BRYONET
I hate to spoil the fun but stems of /Polytrichum// commune often/ grow
to over 1M in length in hummocks in England.
Jeff Duckett
Jeffrey G.Duckett, BA PhD (Cantab.), Professor of Botany, School of
Biological & Chemical Sciences, Fogg Building, Queen Mary, University of
London, Mile End Road, London E1 4NS Tel: (++44)(0)208 882 7485 email:
j.g.duckett@qmul.ac.uk
BRYONET
> BRYONET
>
> Where is Sphagnum fuscum so common and important?
In the northern part of European Russia and the major part of West Asian Russia
and the southern part of Eastern part of Siberia, Sphagnum fuscum is very
common, often dominating in bogs and sometimes also in open forests. I believe
that in Russia in terms of biomass this is the number one among Sphagna. As
forests in Russia are also quite widespread I'd hesitate to compare its weight
with Hylocomium or else.
In one recent lecture of Prof. Isaev (Institute of Forest, Krasnoyarsk, Russia),
I heard that in Russia the ratio of fixed cardon in bogs to that in forests is
2.3:1. I feel that S. fuscum contributed a lot to this, although I never studied
this topic professionally.
Misha Ignatov
BRYONET
Quick reply. Very little C is stored in the temperate zone. The vast
majority is in the northern boreal zone and that's where fuscum
shines , at least in my opinion. But we should get the peatland
ecologist's opinions. I think they can even identify fuscum! (Sorry
about the taxonomist insult).
Dick Andrus
BRYONET
I will argue that Dr. Andrus' claiming Sphagnum fuscum as the World's
most important bryophyte is actually a meaningless challenge. Unlike
biggest, longest, or widest, there is no objective standard by which
importance can be determined on a world wide basis. Although Andrus
defines importance by carbon fixation, that is not the only criterion
that might be considered important. An entomologist might define
importance as a bryophyte that harbors the greatest diversity of
invertebrates, or feeds the greatest biomass of invertebrates.
Even when considering carbon fixation, primary fixation may not be the
best measure of importance. Here northwestern North America are the
most productive forests in the world, the old growth conifer rain
forests. The ongoing productivity of these forests is dependent on
cyanolichens providing a constant input of fixed nitrogen and the
mosses which scavenge micronutrients out of the rainfall. If the whole
world were occupied with a temperate rainforest like ours, it would be
not difficult to make a case for Antitrichia curtipendula (the
dominant canopy moss) being the most important bryophyte in the world.
Without Antitrichia and Isothecium, the carbon fixation of these
forests would be sharply restricted. Sphagnum fuscum is simply not
important in this ecosystem.
I think I could make a more confident nomination of the world's most
beautiful bryophyte. I have some candidate images to present. This
might address the request of Rajendra Lavate, at least a little bit.
What we need is a central web site to host the nominees. Maybe the IAB
blog site?
David H. Wagner, Ph.D.
Northwest Botanical Institute
P.O. Box 30064
Eugene, OR 97403-1064
davidwagner@mac.com
541-344-3327
BRYONET
Dick and other bryonetters,
Where is Sphagnum fuscum so common and important? Based on our local
bogs and fens, and most other temperate zone habitats I have
encountered, I would have guessed S. russowii or S. magellanicum or some
other species a bit closer to the water table. How does S. fuscum fare
in old peat? Is it a dominant member, or are other species more
abundant? I hope some of our fossil peatland bryologists will chime in
here. This is actually a very important question!
Janice
--
*****************************************
Dr. Janice Glime, Professor Emerita
President of IAB; Manager of Bryonet
(Michigan Technological University)
219 Hubbell St.
Houghton, MI 49931 USA
email: jmglime@mtu.edu
home: 906-482-1610
fax: 906-487-3167
*****************************************
BRYONET
I think we need a new category- World's most important bryophyte- for
which I nominate Sphagnum fuscum! I believe no other bryophyte even
comes close with respect to amount of carbon fixed and stored. It may
even be possible that without this species world climate patterns
might be different! If nothing else this ought to start a good
argument. If not, I'll just assume I'm right.
Then once we've settled this, we should do the "world's most
beautiful bryophyte".
Dick Andrus
BRYONET
Here is a picture of Dawsonia superba together with people for scale, as
described along the Silau Silau trail, Mt Kinabalu, Sabah, taken in 1995.
It is not a posed picture I'm afraid, taken very much on the hoof (1/6"
wide open), but it does give a good impression of what it really looks
like in the forest. I have plenty of close-ups which are technically
better but lack people for scale. The height of 850 mm was measured from
a plant in this patch, or nearby. Close-up shots show that the plants
really were free-standing, unlike as in the photograph at:
http://www.anbg.gov.au/bryophyte/photos-captions/irwan-rainforest-2006.html
.
Sean
~~~~~~~~~~~~~~~~~~~~~~~~~
Sean Edwards, Vine Cottage, The Street, Thursley, Surrey GU8 6QF
email: sean.r.edwards(at)btinternet.com
==================
BRYONET
On the ANBG (Australian National Botanic Gardens, Canberra, ACT,
Australia) website (www.anbg.gov.au) in the Bryophyte pages
(www.anbg.gov.au/bryophyte) there is a photograph by Murray Fagg of a
human squatting beside a medium sized clump of one of the Dawsonia
species (possibly D. superba or D. polytrichoides, no voucher) in an
eastern NSW forest
(http://155.187.10.27/bryophyte/photos-captions/irwan-rainforest-2006.ht
ml)
Regards,
Judith Curnow, Cryptogam Collection,
CANB Herbarium (ANBG-site), GPO Box 1777, Canberra, ACT 2601, Australia.
Please consider the environment before printing this email.
BRYONET
Date: Fri, 28 Nov 2008 00:39:04 -0800 (PST)
From: BC Ho <calyptrochaeta@yahoo.com>
Subject: Re: BRYONET: World's most extreme bryophyte (in terms of size)
To: bryonet-l@mtu.edu
Thanks to everybody, we have now several suggestions as candidates for the
World's largest in terms of height (self-supporting) (Dawsonia, Spiridens,
Dendroligotrichum), area (Pterobryella), and length (not self-supporting)
(Fontinalis, Sphagum majus, Polytrichum). On the other hand, there is
only one suggestion of Discelium nudum as a contender for the smallest, apart
from the one that I originally suggested (Ephemeropsis), although I do not know
which of the two species of Ephemeropsis is smaller. With respect to the
smallest bryophyte, I would suggest to disregard the protonema phase
and only consider the leafy or (in the case of liverworts) thalloid
gametophores. This would also help to overcome the difficult problem of
'connectivity' especially in the case of mosses where protonema that derive from
a single spore can sprout several gametophores. I suppose this also applies to
the largest when we want to consider a single plant. Going back to the original
question, anymore suggestions to the tiniest bryophyte? In terms of sporophyte,
Splachnum luteum and S. rubrum are suggested to have the longest seta. Does
Dawsonia also has the largest capsule, as Neil Bell pointed out?
It is interesting that all comments so far are restricted to only mosses. I am
interested to find out what are the giants and dwarfs in the world of the
liverworts. Could there be a reason to why bryologists do not talk (much) about
liverworts when it comes to size, or it is just me who is unaware and not
well-informed?
Most sincerely,
Boon-Chuan
_____________________________________________
Arbeitsgruppe Bryologie
Nees-Institut fur Biodiversitat der Pflanzen
Rheinische Friedrich-Wilhelms-Universitat Bonn
Meckenheimer Allee 170,
53115 Bonn, Germany
Fax: +49 228 73 6542
www.bryologie.uni-bonn.de
BRYONET
Dear Bryonetters,
I had some trouble to find the image Dawsonia sp. - showing the size of the
plant. Finally I succeeded with
http://www.anbg.gov.au/bryophyte/photos-captions/irwan-rainforest-2006.html
There are many more nice images of bryophytes available with
http://www.anbg.gov.au/bryophyte/image-link-list.html
Regards
Michael Häusler
Weinheim, Germany
BRYONET
I found this photograph here:
http://www.anbg.gov.au/bryophyte/photos-captions/irwan-rainforest-2006.html
david
David H. Wagner, Ph.D.
Northwest Botanical Institute
P.O. Box 30064
Eugene, OR 97403-1064
davidwagner@mac.com
541-344-3327
BRYONET
On the ANBG (Australian National Botanic Gardens, Canberra, ACT,
Australia) website (www.anbg.gov.au) in the Bryophyte pages
(www.anbg.gov.au/bryophyte) there is a photograph by Murray Fagg of a
human squatting beside a medium sized clump of one of the Dawsonia
species (possibly D. superba or D. polytrichoides, no voucher) in an
eastern NSW forest
(http://155.187.10.27/bryophyte/photos-captions/irwan-rainforest-2006.ht
ml)
Regards,
Judith Curnow, Cryptogam Collection,
CANB Herbarium (ANBG-site), GPO Box 1777, Canberra, ACT 2601, Australia.
BRYONET
Very interesting topic indeed!
I hope some of you will have pictures of these extreme bryophytes to post to the
IAB blog. That will be very nice.
Please share your pictures in the blog. If you need help on how to register and
publish your blog entry, please email me.
Or send me your jpg files and I will do the upload for you.
Thanks so much.
Efrain
Dr. Efraín De Luna
Depto. de Biodiversidad y Sistematica,
Instituto de Ecología AC,
Apdo. Postal 63,
Km 2.5 antigua carretera a Coatepec # 351,
Congregación El Haya,
Xalapa, Ver 91070, México
http://www.filogenetica.org/personales/deluna.htm
Sistematica en el INECOL
http://inecolsistematica.blogspot.com/
BRYONET
All these comments about the tallest bryophyte are very interesting to
this non-bryologist lichenologist/mycologist. I wish there were good
illustrations of these species. All the photographs that come up for
/Dawsonia /on a Google Image search are beautiful, but could be almost
any Polytrichaceous moss since there are no scales included. What I
would like to see is a photograph with a human (or readily recognized
breed of dog, etc.) in the picture for scale. A photograph that
includes both gametophytes and sporophytes /in situ/ would be
wonderful. Such a photograph would be very useful in lectures to
introductory biology students. I have a hard time getting students very
interested in the bryophytes (they go by pretty fast in our coverage)
and a memorable image would be helpful. The Scandinavian mummy in the
peat bog is what I use now.
Any possibilities?
Fred Rhoades
Western Washington University
Bellingham, WA
BRYONET
This interesting topic came up in 2003, and no doubt before. It started
as a highest (altitude) and lowest (depth in water) topic. For those
that haven't access to the archives, here are extracts:
I posted on 5 Mar 2003: "I know that I have read [unsubstantiated?] of
records of Dawsonia superba exceeding 1 m. I have personally measured
it at 850 mm on the Silau Silau Trail, Mt Kinabalu (29 Aug 1995). And
this was just a passing patch, nothing sought out for its height. One of
the things about Dawsonia is that the individual stems are
self-supporting, and although Polytrichum commune can get pretty tall I
doubt that it ever exceeds about 250 mm free-standing."
An extract from the BBS Travelling exhibition (written 1986-7): "Mosses
and liverworts vary in size almost as much as do flowering plants. It is
difficult to say what the biggest moss is, because all of one very large
clump may have grown from one spore. The Giant Haircap Moss Dawsonia
superba, from South East Asia and Australasia, can reach heights of over
a metre. The similar but slightly smaller British moss Polytrichum
commune can form clumps of about 70 cm height, but the individual stems
are not self-supporting. The long flowing stems of the river moss
Fontinalis exceed a metre. The mosses that hang in festoons in tropical
forests are probably longer still."
I have myself measured Polytrichum commune at 700 mm (excluding fruit)
at Lindow Moss and also in Devil's Punch Bowl, UK, agreeing with
Janice's report, but it was in a mound both times.
Gordon Rothero wrote (7 Mar 2003): "I have a stem of Polytrichum commune
from NW Scotland which is 75cm long - part of an extremely large hummock
- but only the final 15cm or so of this will stand erect without
support."
Rune H. qkland wrote (7 March 2003): "Fontinalis antipyretica, which may
abound in small streams (in Norway). It may also reach more than 50 cm,
not in height, but in length, all green."
Guy Brassard wrote (9 March 2003): "Sphagnum also grows very long.
Sphagnum majus in Newfoundland certainly grew to more than 1 m, albeit
in an aquatic habitat (I remember taping one stem to a piece of
cardboard)."
Answering Neil Bell's question about lamellae as a measure of leaf
area, I made a crude calculation many years ago, haven't checked it
since but looks OK, here pasted from lecture notes: "Mosses such as
Polytrichum have developed other mechanisms to control water loss. Along
the surface of each leaf run dozens of ribbon-like lamellae; a small
movement of the leaf will reveal a photosynthetic area about many times
that of the original leaf surface. A simple calculation shows that the
factor increase of surface area is 2X lamella-height in number of
green cells surface area exposed, so for example lamellae five cells
high will have ten times the surface area exposed. If the lamellae are
capped with impermeable cells, then the percentage exposed area goes up
from 0% to 1,000% of a simple leaf without lamellae." Otherwise,
Rhodobryum giganteum would be a contender.
Sean
~~~~~~~~~~~~~~~~~~~~~~~~~
Sean Edwards, Vine Cottage, The Street, Thursley, Surrey GU8 6QF
email: sean.r.edwards(at)btinternet.com
------------------------------------------------------------------------
BRYONET
There are some really big Polytrichadelphus spp. in the Andes (Peru,
Columbia), e.g. P. giganteus and P. ciliatus, but I don't think these
are recorded from Brazil. There are some highly unusual (although not
large) endemic Polytrichaceae in Brazil however (Itatiella, Oligotrichum
riedelianum), as well as one or two poorly known Polytrichum "names" in
addition to the well known species, so perhaps there are some monsters
out there!
Like Juan Larrain I have also seen some very large Dendroligotrichum
specimens in Chile (although not quite 60cm); I have also seen some
pretty small alpine forms however. I suppose the problem in picking a
"winner" is definitions. Is the largest species the one that has
produced the single largest specimen known, or the one that commonly
produces the largest plants (how commonly...?). "Self-supporting" is
also a continuous variable in practice; some plants are long but
buried in the substrate, pendent (to varying extents) or completely
prostrate, others erect but with varying degrees of "denseness" of
growth... "Longest" and "largest" (in the sense of total biomass of an
individual plant derived from a single protonemal bud) can be
objectively measured but are perhaps not very interesting or significant
in themselves, while other measures of total plant size, that better
encapsulate what we think of as "big", are difficult to quantify.
Neil.
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Neil E. Bell
Postdoctoral Researcher
(Bryophyte Systematics)
Kasvimuseo
PO Box 7
00014 University of Helsinki
FINLAND
+358 9 191 24463
neil.bell@helsinki.fi
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BRYONET
Was it really a single growing plant? Polytrichum mostly grows in large
'cushions' and is not self-supporting in such a case (in contrast to Dawsonia or
Dendrooligotrichum for example).
Cheers,
Volker
---
Volker Buchbender
Clara-Viebig-Str. 5
01159 Dresden
Germany
BRYONET
Hi Bryonetters,
I've seen a Polytrichum gametophyte, collected in Southeast Brazil by Daniel
Vital, which measure more than 80 cm. Then, we have a new recordist for the
category tallest self-supporting orthotropic moss. Unfortunately, I don't
know which is the species.
Marina Santos
BRYONET
Maybe not a world record but I have here a Scorpidium scorpioides that
reach 60 cm (and I'm now sorry I was not more careful in collecting the
older parts).
And shall we consider the underground parts of Climacium ? Has anybody
been more patient than me who stopped digging after collecting 25 cm of
rhizome (wich I would think is rather short, but this is a question
actually) ?
I would suggest Discelium nudum as a contender for the smallest
gametophyte (we have so separate gametophyte from sporophyte, right ?),
but then this will take us nowhere (smilling here), because, well, shall
we consider protonema ?
Jean Faubert
BRYONET
Correction: The very long Sphagum from Newfoundland was S. majus, not S.
macrophyllum. So it certainly lived up to its name.
Guy Brassard
BRYONET
When I was in Newfoundland, I remember collecting a specimen of Sphagnum
macrophyllum which was more than a meter long; we had it dried and attached
onto a bristle-board for showing its extreme length.
Guy Brassard
Guy R. Brassard
1270 Alloway Cres.
Ottawa, ON K1K 3Z1
(613) 745-9337
BRYONET
Although Dawsonia may get the prize for being the tallest
self-supporting /orthotropic/ moss and possibly also for having the
longest leaves and the largest capsules, it has close rivals amongst the
austral and SE Asian tropical pleurocarps for the title of largest
self-supporting moss. Some examples of Spiridens spp. (e.g. S.
reinwardtii) certainly exceed 40cm, growing almost horizontally from the
trunks of trees. Pterobryella longifrons and P. papuensis grow in a
similar manner, and while they may not be quite as long they are
regularly pinnately branched, so the total self-supported surface area
is impressive! However it is measured, these must be amongst the most
visually striking mosses on the planet in terms of size, although they
are much less well known than Dawsonia and hardly ever mentioned in
general texts. Definitely an unexploited resource for drawing mosses to
the attention of the general public! Largest leaf area? Hmmm, are the
lateral surfaces of lamellae allowed to count towards the total?
Neil Bell.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Neil E. Bell
Postdoctoral Researcher
(Bryophyte Systematics)
Kasvimuseo
PO Box 7
00014 University of Helsinki
FINLAND
+358 9 191 24463
neil.bell@helsinki.fi
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BRYONET
Hi Boon-Chuan Ho,
I think this is a quite interesting topic for bryonet.
Recently I collected in the extremely humid lowland rainforests of southern
Chile (Aison Region) some huge specimens of Dendroligotrichum dendroides,
the tallest measuring 59 cm! The forest floor was plenty of this species,
and it was the "king" of a very interesting mini-ecosystem, with several
moss and liverwort species livind in its "shade". It was my first meeting
with the beautiful Rhaphidorrhynchium dendroligotrichum, a tiny moss species
that is know to occur ONLY as an epiphyte on Dendroligotrichum dendroides.
Since then I have been wandering if there are records of Dawsonia superba
taller than these plants.
Maybe somebody on bryonet can tell me.
Juan
Juan Larrain B.
Departamento de Botanica
Universidad de Concepcion
Casilla 160-C, Concepcon, Chile
musgoschiloe@gmail.com
Fono: (56) 41-2204418
Fax: (56) 41-2246005
BRYONET
There was a picture of Fontinalis, being held by Jack Sharp, in one issue of
the Bryological Times, but with a quick search today I did not locate it. It
was about 2 meters long, and if we count branches...
I think there are a few other references to record size (large, but not
small) in several issues of the Times, with a series some years ago.
Janice
--
*****************************************
Dr. Janice Glime, Professor Emerita
President of IAB; Manager of Bryonet
(Michigan Technological University)
219 Hubbell St.
Houghton, MI 49931 USA
email: jmglime@mtu.edu
phone: 906-482-1610
fax: 906-487-3167
*****************************************
BRYONET
I would offer suggestions of Splachnum luteum and Splachnum rubrum for the
longest setas I have come across. Followed closely by Meesia triquetra. I
think I have material in my herbarium of Splachnum luteum where the seta is
around 15cm (the specimens are boxed ready for transfer so I cannot check). For
Meesia triquetra, the setas are around 10cm (again, I can't check the
measurements at the present time).
Prof. Rod Seppelt,
Principal Research Scientist,
Australian Antarctic Division,
Channel highway,
Kingston 7050,
Tasmania, Australia
ph: +61 (03) 6232 3438
FAX: +61 (03) 6232 3449
e-mail: rod.seppelt@aad.gov.au
---------------------------------------------------------
BRYONET
Good Morning Fellow Moss Lovers
I'm proud to share another moss article with you. "Small Miracles" is a
feature article about Mossin' Annie's creative use of eco-friendly mosses in
Leslie Henry's private Zen moss retreat in Brevard, NC. Published in *Carolina
Home and Garden Magazine*, Winter/Holiday Issue, 2008. pp 110-115, the story
is written by Kate Reynolds with photographs by Rimas Zailskas. Special
thanks to Kate for capturing moss magic with her eloquent words and to Rimas
for sharing the marvels of the miniature world of mosses through his
outstanding photographs.
Visit Carolina Home and Garden web site to view Moss article online:
http://www.carolinahg.com/pages/current-issue/holiday-08/small-miracles.php
To get your own subscription to Carolina Home and Garden Magazine, please
register online at: http://www.carolinahg.com/pages/subscribe.php
FREE copies of Carolina Home and Garden Magazine are available at a number
of locations in western North Carolina. To find out where to get your own,
visit: http://www.carolinahg.com/pages/where-to-find-us.php
OR JUST READ THE ARTICLE THAT FOLLOWS:
"Small Miracles"
Carolina Home and Garden Magazine
Winter/Holiday 2008
By Kate Reynolds
Sometimes you have to look beyond the obvious to enjoy nature's gifts. They
hide in unexpected places, waiting for the patient observer to discover
them. Take Leslie Henry's backyard, for example. From the sidewalk, her tidy
contemporary house at the end of a cul-de-sac in Brevard doesn't seem the
type to harbor secrets. But walk around to the back and you enter into
another world: a tranquil sanctuary where every step is cushioned by a deep,
verdant carpet of living green. Welcome to the moss garden.
Tucked at the base of a steep hillside and set beside a lyrical mountain
stream, Leslie's little bit of heaven is a tapestry of textures and hues.
Shaded by tall trees and bordered by stands of ferns, it engenders a sense
of shelter and peace. The ambiance is hushed and ancient.
The garden is fairly young, however, set in place not by decades of slow
growth but in the past year by the magic touch of Annie Martin, better known
as "Mossin' Annie," a local champion and collector of bryophytes - native
mosses. "It was designed to create the effect of a miniature landscape using
varieties from more than 450 types of indigenous bryophytes that we have in
Western North Carolina," Annie says proudly.
Indeed, the effect of looking over Leslie's moss "lawn" recalls viewing the
countryside from the window of an airplane: hills and valleys, an expanse of
forest. There's a rock garden that stands in for a mountain range. It is a
world in microcosm, presided over by a placid seated Buddha statue whose
benign countenance reflects the abiding spirit of the place.
Leslie has a sense of connection to the orient=97her father grew up in Chin
a,
where his father worked for the YMCA. Many treasured pieces of eastern art
grace the interior of her home, and eastern philosophies inform her
worldview.
"I do study and practice Buddhism," she explains, "and my original idea was
for a Zen garden. There was moss here to begin with and because of the
mountain it doesn't get much sun. I've always loved moss and it seemed like
the perfect thing to make it all go together and create an attractive
space."
Mossin' Annie was the ideal partner in manifesting this vision. Petite and
impish, with a penchant for dressing in various shades of purple, Annie has
the air of a charming woodland sprite but is, nonetheless, a very determine
d
woman when it comes to her beloved bryophytes. Her passion is the
preservation of native mosses.
"We have plenty of opportunities to collect and rescue mosses in Western
North Carolina," she says. "There's considerable development that continues
to occur. We work with green developers, the Department of Transportation
and people who are environmentally conscious. They contact us when they're
going to build houses, roads and golf courses and we go in and rescue the
mosses first. The goal is to use them in public or private gardens or,
ideally, to reintroduce them into the community once it's completed."
Leslie's garden is an amalgam of rescued and resident mosses. "Some of the
moss was introduced, but in other areas I took advantage of what was
naturally occurring," Annie explains. "She inherited some good bones from
the previous homeowners, but the rock garden was almost invisible - it was
overwhelmed with hostas." Carefully edited plantings now punctuate the beds,
set amid the moss hummocks and lichens, like 'British Soldiers,' which were
added "for extra accents of delight."
"Mosses are great companions with every plant," Annie says. "They're green
year-round, so when the other annuals and perennials die back, you still
have color. They provide a contrast for bright plants and they're a great
alternative to wood mulch. They don't leach nutrients from the soil and they
help to retain the moisture and provide insulation from the cold."
Resilient and low maintenance, mosses literally live on air and water. "The
leaf of the plant is only one cell layer thick," explains Annie. "It absorbs
all of the water. It has no vascular system - it doesn't have any roots to
absorb water or nutrients. It lives solely on rainfall and dust particles.
So it's extremely tolerant to all kinds of conditions.
"According to the botanists, mosses are 400 million years older than
vascular plants like herbs, so before there was just about anything else,
there were mosses=97and they'll probably outlive all of us."
For Leslie, mosses' sturdy character makes tending to her retreat a fairly
simple task. "I do occasional weeding," she says, "and [the moss] doesn't
like to have leaves on it, so I pick them up or blow them off. It needs to
be watered fairly often, but it takes very little water. I can just mist it
with the hose and you can see how the green just picks right up."
Even the mischief of a local skunk, which attempted to rearrange the moss
beds one night, was easily repaired. Uprooted patches were simply put back
into place and pressed down firmly underfoot. "In fact," says Annie, "the
last phase of the moss planting process, after you've watered it, is to step
on it, and keep stepping on it. That helps it set itself. And you can sit on
it any time you like=97you just might get a wet bottom."
Annie would certainly encourage everyone to sit down and engage the moss up
close. It's there that these wondrous plants truly reveal themselves. "You
need to take a closer look at mosses," she urges, and offers the loupe that
hangs around her neck like an amulet. The magnified plants are exquisitely
detailed: some resembling miniature ferns, others like tiny green
starbursts.
"The immediate impact of the moss garden is the expanse of green," she says,
"but there is another element of color that only comes during the
sporophytic stage." Sure enough, at closer inspection, some of the small
mounds are surrounded by halos of spores; a miniature fireworks display,
just inches from the ground.
This just goes to show that sometimes you find amazing gifts in unexpected
places, like a compact backyard on an ordinary street where ancient plants
invite you to experience the hush and share in the mystery of the complex
world beneath our feet.
"You don't have to be a Zen Buddhist in a garden in Kyoto, Japan, to enjoy
mosses," says Mossin' Annie with a smile. "You can be right here in Western
North Carolina and love them too."
Mossin' Annie offers workshops, presentations, on-site bryophyte
identification and moss rescue, along with moss garden design. For more
information, visit www.mountainmossenterprises.com or call 828-577-1321.
-----------
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Moss!
Take care,
Mossin' Annie
--
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mossinannie@gmail.com
Mountain Moss Enterprises
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Moss mirrors the intricacies of your inner self.
BRYONET
Paul Wilson wrote to Ken Kellman:
"The problem (that our current taxa are not meant to be monophyletic and
often are not) already exists, and the phylocode + developing a good
rank-free classification would not CAUSE the problem; it would partially
alleviate a problem that already exists. You can't get rid of the
problem by ignoring it."
My own response: There is no problem, in my view, beyond
phylogeneticists wanting to name clades and needing to find ways to
modify and make use of present manner of naming taxa as a way to name
clades. That taxa are not meant to be monophyletic is not a problem
because they are meant to be evolutionary units (explanatory of
evolutionary theories) not monophyletic clades.
"Those of you who are concerned with not destroying the traditional
classification should be the biggest proponents of the Phylocode. Until
we have a phylocode, systematists will continue to wreck havoc on
traditional usages of names to try to make them correspond to clades
that they want names for."
My own response: Yes, yes, I agree that havoc should be avoided. Two
codes of classification might do this. On the other hand, unless you
split phylogeneticists from systematists, and I am one of the latter,
then I get to comment on the Phylocode as representative of a major bloc
of systematics researchers. The Phylocode classifies clades but does not
completely deal with evolutionary entities (splits evolutionary taxa and
ignores unique directions of evolution). To the extent that the
Phylocode represents systematic endeavor and fails to maximize
evolutionary information in classification, I demur, take exception, and
object.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Ken Kellman plunks for two separate systems, one focusing on clades, the
other allowing paraphyly. Sounds good, but remember that at least in my
opinion, clades do not reflect evolution, only genetic continuity and
isolation events. The Phylocode would be limited to classifications
based only on patterns of clades, which is good for some kinds of
research but not for others. In my opinion, the same evolutionary taxon
can appear in two different clades, as witness the overwhelming evidence
from "massive homoplasy" and fully cryptic species.
Ken hits the nail on the head, though, as he says:
"Perhaps the real problem comes when we try to blend the two systems as
in the Goffinet et al work that generated this whole discussion. This is
a hierarchical system that enforces strict monophyly."
The Goffinet et al. work (which might be called Moss Phylogeny Group
III) is a mighty contribution as a summary of recent study, don't get me
wrong. We are better for it. I am complaining only about the
disappearance of certain evolutionarily important taxa (Ephemeraceae,
Splachnobryaceae, Cinclidotaceae) by submerging them (at least in
Pottiaceae) without discussion, administratively, by invoking the
classification system called monophyly. I feel monophyly misrepresents
evolution in not recognizing strong and unique but nonmonophyletic
directions of evolution.
Does anyone have complaints about similar examples? Are there other
taxonomists who can't find their taxa?
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Thank you for your contribution Ken. I agree with the theme of your
last paragraph, but if my understanding is correct the phylocode and
a separate rank-free classification would give relief to the
friction, not exacerbate it. I disagree with the implication that
embracing the phylocode would somehow undermine public policy, such
things as the Endangered Species Act, and the understanding of
evolution by the public (at least those with an open mind, like kids
visiting museums).
1. The problem (that our current taxa are not meant to be
monophyletic and often are not) already exists, and the phylocode +
developing a good rank-free classification would not CAUSE the
problem; it would partially alleviate a problem that already exists.
You can't get rid of the problem by ignoring it. It is undesirable
and totally impractical to deny the developments of phylogenetics
over the past few decades.
2. The phylocode doesn't outlaw the current codes. They would co-
exist. Species and other ranked taxa would continue. People would
still describe new species. Species could still be protected. All
that would change is that specimens in those species would also be
referable to a hierarchy of named phylotaxa.
3. There's the Phylocode and the phylocode. Currently, the Phylocode
is only in review above the level of genus, thus doesn't even (yet)
apply to anything remotely close to the species level. People are
going to name clades and they should name clades. What the phylocode
does is lay out some rules for naming the clades and designating what
those names shall mean to subsequent authors. Without a code, we're
living in a land without laws.
Looking far into the future, after the phylocode applies to every
level, and a great many phylotaxa have been described appropriately,
then traditional paraphyletic taxa like Reptiles, Fish, Bryophytes,
and (I presume) Syntrichia ruralis will be highlighted by how they do
NOT fit into the phyloclassification, they will be highlighted as
macroevolutionary formations that are stable and interesting and all
the more so because their names remain in usage despite having given
rise to phylotaxa that have left them behind. Those of you who are
concerned with not destroying the traditional classification should
be the biggest proponents of the Phylocode. Until we have a
phylocode, systematists will continue to wreck havoc on traditional
usages of names to try to make them correspond to clades that they
want names for. Or so I reason.
Respectfully,
Paul Wilson, Professor
Department of Biology
California State University
Northridge, CA 91330-8303
818-677-2937 FAX: 818-677-2034
For printable reprints: https://www.csun.edu/~hcbio028/cv.html
For pictures of bryophytes: https://www.csun.edu/~hcbio028
To listen to my like-radio show: https://www.csun.edu/~hcbio028/
EvolutionReport.html
BRYONET
I have been watching this wonderful discussion, and although I must
confess that I have not understood all of the finer points, I have
learned a tremendous amount. I want to thank Brent and Richard for
working so hard on this thread. I also want to thank Bernard Goffinet
for the work that started it all off.
I want to examine another aspect of this question, that of public
opinion. Although it is obvious that public opinion must not ultimately
be the arbiter of scientific decision, we do have to be aware of how
science is viewed by the layperson. Here is an example that even the
least knowledgeable person can understand. Most would agree that birds
have evolved from reptiles. Are birds then reptiles? Obviously not! A
five year old can tell the difference. But strict monophyly would
dictate that birds be sunk back into the reptiles. The response of the
strict monophyleticists is to remove all hierarchical ranking. This of
course solves the problem. We can have the bird clade and the reptile
clade, and just say that the bird clade is a part of the reptile clade.
We have not lost the evolutionary information, and we have recognized
the two different groups. The problem comes to the smaller clades, what
we may now call genera and species. We do not now have an endangered
clade act. We have an endangered species act. Can you imagine the uproar
from those who already want to discredit science in public policy when
we tell them there is no such thing as a species? Whether or not the
phylocode is a better description of reality, it seems to me that this
is not an avenue that is available to the scientific community. The
promotion of the phylocode would be a disservice to the very
understanding of our world that it is trying to describe. The public
needs MUCH MORE education for that. An outrageous percentage of the
American people do not even believe in evolution! At a time in our
planet's history where the very survival of major ecosystems may depend
on public support of scientific understanding, we must be very careful.
Another issue is the desire of people to organize chaotic problems. We
give plants names, we group these plants in larger and larger groups,
all in an attempt to sort information so that it can be communicated and
used in ways that are impossible without that organization. I think
Richard's traditional taxonomy reflects this way our brains work, and
thus is more intuitive, and therefore more acceptable to the layperson.
Moreover, the best we can say about any of these cladistic trees (or
evolutionary theories), is that they are the personal opinions of the
author(s). There is never any proof, just high probabilities generated
from the evidence available at the time. We would have no success trying
to sell a non-intuitive description of the world with only personal
opinion and probability as our only proof.
I believe that both viewpoints (hierarchical traditional taxonomy with
its acceptance of paraphyly vs the rankless monophyleticist) must be
maintained, but used in different situations. We can recognize that
nature displays a rankless organization reflecting evolutionary
pathways, but we must recognize that we hide certain information by
losing intuitive names. We can also recognize that strict adherence to
rank has other limitations. We do not have to decide between the two
systems. We simply have to state the method we are using and accept the
consequences. Perhaps the real problem comes when we try to blend the
two systems as in the Goffinet et al work that generated this whole
discussion.This is a hierarchical system that enforces strict monophyly.
I am sure that I have missed several of the finer points of this
wonderful debate, and to a certain extent have demonstrated my ignorance
by speaking up. I still think it is important to keep our ideas relevant
to the times we live in.
Ken Kellman
9870 Brookside Ave
Ben Lomond, CA 95005
(831) 336-8548
kkellman@sbcglobal.net
BRYONET
There have been declarations that the arguments of the present thread on
paraphyly and phylogenetics will not change minds. What might be the
real basis of intransigence in the face of apparently cogent arguments
on either side?
Could it be a simple, practical choice is what is being wrestled over?
Some want to classify according to groupings of clades and nought else
(phylogeneticists), others tacking on rank changes for unique traits
(evolutionary taxonomists).
Is this something like an argument over which is the best way to arrange
an herbarium, alphabetically or "naturally" e.g. Bentham and Hooker, or
Engler, or Thorne, or whoever has the latest broad classification?
Alphabetical arrangements are immensely convenient but larger groupings
are exploded; but natural arrangements group genera into families so
someone who studies a family has them all together. Some arrange the
families by a natural linear arrangement, but put genera under the
families alphabetically, which is a nice compromise.
Monophyly is not a theory, but a system of classification, in my opinion
adopted so lineages alone can be the basis of classification. There is
no force in Nature called monophyly that requires a new genus to
diversify its lineage only as a sister group to another genus, or a new
family to be only a sister group to another family. Given this, then
there is a choice between monophyly and paraphyly in classification that
can be idiosyncratic. It is more library science than systematics.
Phylogenetics has contributed a fine method of analyzing morphological
relationships (parsimony) on the basis of some but not all
evolutionarily important traits, and of distinguishing molecular genetic
continuity and isolation. I submit that phylogenetic adherence to
monophyly in classification, however, excises equally important
information on new evolutionary directions (nonmonophyletic genera and
families). If the Pottiaceae were represented in a future floristic book
following the MPG III, then there would be no diagnoses of Ephemeraceae,
Splachnobryaceae or Cinclidotaceae.
Biodiversity measures and triage decisions are now commonly based on
phylogenetic (patristic) distance between lineages (that is, summing the
intermediate branch lengths is a measure of how long clades have evolved
away from each other), but not how much clades or taxa have evolved and
in what unique respects.
Is this the difference between two camps, how we are to arrange our
herbaria? At what cost to science?
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
I appreciate your wonderful response, Efrain! I used the phrases
"monophyly-mad" and "innocent students" only to encourage contribution
to the discussion. Outrage is a great way to elicit sharing of
information and opinions, which drives genuine advances.
Efrain wrote:
"I was converted to think in terms of phylogenetic theory and methods as
a way to decide among competing hypothesis (Hs) of biological groups as
lineages (species, genera or any level of inclusiveness)."
and
"For the particular area of research that has to do with the making of
classifications it is certainly true that numerical phylogenetic methods
are by far the robust option to select hypotheses of groups, characters
and change."
Yes, I agree, in part.
I am interested, however, in evolutionary taxonomy, which maximizes
evolutionary information in classification (working with Linnaean
classification). Lineages and level of inclusiveness are okay but only
part of evolution. Note that you select the most robust of phylogenetic
hypotheses, not evolutionary hypotheses. E.g. if you compare support for
Ephemeraceae as a family apart from the Pottiaceae with lumping it,
there is no support when only phylogenetically informative traits are
used. Autapomorphies are ignored.
Suppose the Ephemeraceae occurred at the base of the Pottiaceae as a
sister group? It would be recognized as a separate family. Given there
are many genera in the Pottiaceae, the chance the Ephemeraceae would
differentiate at the base of the Pottiaceae rather than from a distal
clade is 1 divided by the number of Pottiaceae genera in the cladogram.
This is genuinely arbitrary, and the concepts of the evolution of this
family are affected (by deletion of the family description in literature
based on the classification) by an rigid enforcement of monophyly.
If you select hypotheses of "groups, characters and change" based only
on relative branching of lineages, then anagenetic, autapomorphic
information is missing from the classification. This may include
important evolutionary information such as a description of a family
which may be deleted from the literature if the family is lumped in an
influential (phylogenetic) classification. This definitely affects
biodiversity study, since degree of change is only reflected as relative
degree in phylogenetics, not absolute degree as in evolutionary
taxonomy.
Your fellow innocent,
R.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
I have been copying and pasting into the blog the recent exchange of ideas on
systematics, homology, even statistics.
Now I read that some of us were innocent students. Well, Rich, you know me well
too much that my innocence has not vanished from my student days,, it just has
evolved and adapted to local conditions ... :)
As one innocent former student of a "monophyly-mad phylogeneticist" (aka Brent!)
I have to confess: I was converted to think in terms of phylogenetic theory and
methods as a way to decide among competing hypothesis (Hs) of biological groups
as lineages (species, genera or any level of inclusiveness). I was thought to do
research gathering data (morphological, molecular, etc) and performing relevant
analyses (statistical, phylogenetic, or else) to select hypotheses about
characters and groups with at least two expectations: it is the best H to
explain currently available data (under some optimality criteria, such as
parsimony, likelihood or posterior probablilities), and it is the best H that
has higher chances to survive if more data is added later (under some measure of
corroboration, support or robustness).
Thus, I distinguish concepts and methods that are applicable to each of
different areas in this pluralistic chain of research: biodiversity,
explorations, floristics on one side, and the actual making of the taxonomic
groups and revisions of them on the other side. For the particular area of
research that has to do with the making of classifications it is certainly true
that numerical phylogenetic methods are by far the robust option to select
hypotheses of groups, characters and change. This is the approach that I in turn
teach to another paraphyletic group of innocent students.
I hope this does not make me too soon a "monophyly-mad phylogeneticist v2.01"
saludos!
E
Dr. Efraín De Luna
Depto. de Biodiversidad y Sistematica,
Instituto de Ecología AC,
Apdo. Postal 63,
Km 2.5 antigua carretera a Coatepec # 351,
Congregación El Haya,
Xalapa, Ver 91070, México
http://www.filogenetica.org/personales/deluna.htm
Sistematica en el INECOL
http://inecolsistematica.blogspot.com/
BRYONET
Brent Mishler has indicated that he will no longer participate in the
discussion on paraphyly because:
(1) Nobody will learn anything since the alternatives are black and
white, and Mishler or Zander won't give up.
Reply: Everybody is learning things, Brent, particularly myself, and
witness the general interest (Bryological Times and IAB blog). John
Maynard Keyes once said, "I change my mind when new information appears.
What do you do?" I particularly like my phrase "monophyly-free
phylogenetics" which is a nice meld of two extreme points of view, and
represents a softening of my views. What do you do?
(2) The debate reprises old debates of 25 years ago.
Reply: The molecular dimension was not there 25 years ago in the way it
is today. The way it is now used should be publicly discussed. The old
debates were between pheneticists and cladists, and between pattern
cladists and, what?, regular cladists. I advance the following: (1) a
new view on parsimony with morphological traits as just a kind of
cluster analysis, and (2) a much restricted idea of what the molecular
analysis means (continuity and isolation but not necessarily speciation
and Biological Species Concept), and (3) acceptance that in mainstream
classification paraphyly is okay when new evolutionary directions arise
out of the middle of a clade rather than just the base, and should be
recognized by a change in rank.
(3) Everybody important accepts phylogenetics.
Reply: Oh? Then now is time for a good debate, given that everybody
important is wrong. By wrong, I focus on the problems of phylogenetics
(like strict monophyly and emphasis on statistical power, not
reliability), not the good things (parsimony analysis as a kind of
cluster analysis, molecular analysis for genetic continuity and
isolation).
(4) We bryologists are conservative.
Reply: Not me. Maybe Brent is confusing conservativeness with the fact
that we have been a "specialty science" (actually using microscopes)
somewhat isolated from angiosperm research. No longer, I hope.
(5) The future is up to the students.
Reply: Sure. That is why this discussion should be continued, with
particular arguments repeated if necessary. Postmodernists say we are
all in very isolated groups and the only real exchange is in negotiation
across impossible psychological and spiritual boundaries. Nah! Science
will out.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Actual data is wonderful, and Lars' detail of examples of species
problems is illuminating and challenging.
Regarding the first two examples, I would think that Scorpidium
scorpioides evolved from an isolated population of the paraphyletic S.
cossonii, while the same situation would explain the problem with a
paraphyletic species of Antitrichia. One taxon evolving from another,
that is, descent with modification of taxa. Molecular phylogenetic
branches, of course, connect the isolated populations of S. cossonii.
This is expected.
In the third example, with cryptic species having different geographic
ranges, I think a detailed molecular analysis would simply find
disparate range changes in isolated populations of the same species.
In the fourth example, of Drepanocladus aduncus and splitting, a lack of
molecular differentiation of one sequence could just indicate rapid
evolution during speciation, which apparently is commonly reported in
the evolution literature (along with morphological stasis after rapid
speciation, i.e. punctuated equilibrium).
In the fifth example, of Homalothecium, yes, the situation is
complicated, and must be studied. This problem is actually an
opportunity for study of evolutionary changes, something for a graduate
student to consider as a dissertation. Some knotty problems we can throw
up our hands about and leave to the next generation.
Arguing about species definitions make us strong.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Dear all,
This will be my last note on this subject, since Richard and I have
stated our opinions and aren't going to convince each other. No point
in continuing in a "does so, does not, does so, does not..." mode
indefinitely. Besides, this debate was held 25 years ago among
mainstream systematists of the time, and there is a large and
important literature that we don't need to rehash here. The verdict
in most areas of systematics was that monophyletic classifications
based on rigorous phylogenies is the path towards progress. And
incredible progress has truly been made in the last couple of decades
in understanding of phylogenies, classification, and comparative
studies based on those. My colleagues in animal, fungal, and
angiosperm systematics are amazed that we are still having these
debates in bryology, actually... But we bryologists are a uniquely
practical and conservative bunch, which isn't necessarily a bad
thing. Not all new ideas in science are good ... but some are, and we
need to adopt those.
The future is truly up to the students -- it doesn't really matter
what the entrenched opinions are of the older scientists in the
field. I would urge students to read the literature, discuss these
issues. and make up their own minds. See which approach is the most
practical and useful in your work...
Best,
Brent
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
E-mail: bmishler@calmail.berkeley.edu
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
An interesting question might involve such complex genomic bases for
species.
How about a species that evolves in one population a different genetic
pathway to create the same character (say drought-resistance or rounded
leaf shape)? We have then two populations evolutionarily exactly alike
except for one trait maintained by a different genomic pathway. Are
these then two different species? The two populations interact with the
metapopulation in the same way. How different genomically must two
populations be, though alike in expressed traits, to be different
species?
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
Oh, no, Dieter, I am not offended. I never indulge in similar remarks
myself. I have promised myself to never mention the name "Lysensko" even
though this discussion evokes my sympathy for the immortal and
incomparable Vavilov, who heroically defended "mainstream" genetics even
unto the Gulag.
Choosing characters from the gut? Plant taxonomists have worked
assiduously for 250 years since Linnaeus to select traits that organize
taxonomic groups. These traits are linked through stabilizing selection,
and it is stabilizing selection that makes taxonomy work in the first
place. Hundreds or thousands of specimens are analyzed through
omnispection, phenetic and parsimony analysis, geographic data, fossils,
and other important information to devise a classification that reflects
both inferred evolutionary lines and new (autapomorphic,
non-monophyletic) directions in evolution. Yes, all the problems you
list are there, and these must be dealt with in evolutionary taxonomy.
DNA nicely tracks genetic continuity and isolation events, but not
necessarily speciation or new directions in evolution (by selection or
drift). Change in non-coding DNA sequences is not evolution, but these
track evolution, and evolution must be inferred by morphologic and other
"traditional" study.
Forcing classification to conform to the artificial stricture
(monophyly) required to make genetic continuity and isolation events
alone the basis of classification is very unfortunate and crippling.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
Multiple tests (= multiple comparisons) is only vaguely like
bootstrapping. One example is a bag full of coins. You want to see if
one of them is loaded (heavier on one side).
You take the first one and flip it 10 times, then the second 10 times,
then the third, etc. Eventually you will come to a coin that comes up on
one side five times in a row. The chance of this is 1/2 to the fifth
power, or only 3 out of a hundred.
Does this mean that this coin is loaded (with a 97% chance of being
loaded?). Of course not, because you are making multiple tests. You need
to flip that (or any) coin many, many times to see if it really does
come up on one side about 97% of the time. The p value is based on long
term frequency of the one coin not a set of coins.
Dividing a set of species into two sets almost always allows different
descriptions of the two sets, no matter which way you divide them. The
only descriptions that really count, however, are those that are much,
much better than any other.
Several sequences are better than one when they are independent and
reflect the same gene history. But they often do not (differential
lineage sorting). The 'rigorous statistical tests' are indeed rigorous,
but often only apply to one gene sequence, and are applied in the
context of emphasis on statistical power (discrimination of new
information) not reliability. Note that the chance of any two lineages
are correct is the product of their probabilities, thus in a cladogram
of all 99% probability clades, no more than 6 clades can be correct
together at a 95% joint probability. This is often okay if only that set
of six clades is being discussed as important. If all clades are at 95%
reliability, then no two clades can be reliable as a set if that set is
important in evolution or classification.
Regarding Neckeraceae and biogeographic support, you need to demonstrate
that such biogeographic support is indeed significant with respect to
that exhibited by any other combination of taxa. In any case, if the
taxa being changed around are not well distinguished in the first place,
biogeographic criteria are scarcely the most important elements in
classification. If the taxa are good taxa that are split to enforce
monophyly, see my paper
Zander, R. H. 2008. Evolutionary inferences from non-monophyly on
molecular trees. Taxon 57: [PROOF] http://tinyurl.com/6hctpa
on why this hides evolutionary information.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
Well, Brent, I guess you read mainly the phylogenetic journals. Yes,
many once-mainstream journals have been co-opted by monophyly-mad
phylogeneticists and their innocent students. If you look at a range of
journals, however, there is much work on biodiversity, floristics,
evolution, and even revisions that ignore the strict monophyly aspect of
phylogenetics.
The real value of phylogenetics for morphology and other expressed
traits involved in evolution is in the non-ultrametric cluster analysis
called parsimony, and the tracking of genetic lines of continuity and
isolation from molecular analysis. These methods I think are or should
be easily subsumed in "mainstream" taxonomy as these have value in
evolutionary taxonomy.
Phylogenetics, unfortunately, has the egregious stigma of enforced
monophyly in its classifications. Mainstream taxonomists reject this
additional feature as presumptive, artificial nonsense, and so commonly
reject phylogenetics in genera. We don't want the baby thrown out with
the bath water, so if phylogeneticists would only see reason . . .
I think I and other evolutionary taxonomists can support the phrase
"monophyly-free phylogenetics" as a synonym of modern evolutionary
taxonomy. Any others with comments on this idea?
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Hi Richard,
"Mainstream" implies the majority view... you are entitled to your
opinion, and have made some interesting points in this debate. But
clearly the mainstream, majority view these days is phylogenetic
systematics; just look at the literature in recent years.
By the way, your mushroom-fueled magic dances sound fun (you know I am
from Berkeley!). :-)
Best,
Brent
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
BRYONET
Statistics is certainly not my strongest area, but if I understood
correctly what Richard means with "multiple tests" or "multiple
comparisons", they are sort of bootstrapping. Of course homoplasy in
nucleotide sequences does occur, but isn't it precisely because of
that that we should have several sequences instead of one? And the
results even then must pass rigorous statistical tests before they can
be considered reliable. Some of the species-groups we have ended up
with in the Neckeraceae would never have been made on morphological
grounds but what is interesting is that they are, almost without
exception, biogeographically very meaningful.
Johannes E.
--
Dr. Johannes Enroth
PhD, University Lecturer, Bryologist
Dept. of Biological and Environmental Sciences
P.O. Box 65
FIN-00014 University of Helsinki
Finland
______
BRYONET
right .....
and the pope said to Galileo Galilei that the sun is circling the earth
as it was observed by esteemed astronomers ..... ;-)
Dear Richard, please don't feel offended by this little polemic comment,
But I felt that your latest comment is a little off and contradicts some
of the nice ideas you had before.
Earlier you argued with unequal gene flow, recombination, hybridisation,
introgression, differing evolutionary rates between taxa and among genes
in a certain taxon, statistics and testing of hypotheses now you choose
characters from the gut.
I don't feel the need to repeat what Volker, Brent and Lars as well as
Johannes already said, but I would wish that rethink about the comment
you made below.
However, I need to comment your opinion on weighting characters. I think
we should have learned from the history of bryophyte taxonomy that some
morphological characters have been overweighted. Thus, I am heavily
opposed to your recommendation of weighting characters according to our
evolutionary concept, this is not very scientific. We should test which
characters are useful and therefore we need something independent of
what we are testing. DNA is such tool with all the problems mentioned
earlier.
Greetings
Dietmar
BRYONET
Certainly we should re-examine the morphological basis of taxa when
apparent homoplasy or paraphyly occurs. On the other hand, splitting any
group of relatively few taxa, say five genera, will create two groups
that are describable. The new "uncovered" or "emergent" traits that
distinguish the two groups may simply be no better than any other traits
that allow diagnoses of two new groups when splitting the five taxa
randomly.
This is called a "multiple tests" or "multiple comparisons" problem in
statistics. Finding a set of traits that allow morphological splitting
to match molecular splitting is NOT corroboration. You must, instead,
demonstrate that the traits you are proposing to base the new
morphological split on are indeed much better than any other combination
when the group of five taxa is split any other way. Only when an
reliable morphological diagnosis is available for the morphological
split can this be corroboration for the reliable molecular split. I have
not seen any such evaluation done though finding morphological traits
are commonly reported as "supporting" molecular splits.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
T: Paraphyly
-----Original Message-----
In such an extreme paraphyletic situation we should perhaps not think so
much about how to classify A, B and C in the first place but to go back
to morphology and re-evaluate the morphological characters that had been
used so far to classify the groups. Quite some morphological characters
used so far are more correlated to e.g. environmental conditions than to
relationships between the groups (e.g. Peristome reduction or length of
the seta, just to name a few). I see the molecular based phylogenies as
a chance to uncover the (un-)reliable characters. Perhaps A,B and C are
not that extremely differing any more when we ignore the unreliable
characters?
Cheers
Volker
BRYONET
Volker Buchbender's view of molecular phylogenies as a way of testing
the (un)reliable morphological characters closely echoes my ideas. And
it seems most of the "traditional" generalizations of which characters
are reliable must go. Given that those generalizations have been more
or less paradigmal what we are witnessing is in fact not an "overhaul"
but a total revolution of ideas. I consider it a privilege to play a
small part in that. To me, as a moss taxonomist and systematist, the
science is right now more rewarding than ever.
Yours truly,
Johannes Enroth
--
Dr. Johannes Enroth
PhD, University Lecturer, Bryologist
Dept. of Biological and Environmental Sciences
P.O. Box 65
FIN-00014 University of Helsinki
Finland
______
BRYONET
In such an extreme paraphyletic situation we should perhaps not think so
much about how to classify A, B and C in the first place but to go back
to morphology and re-evaluate the morphological characters that had been
used so far to classify the groups. Quite some morphological characters
used so far are more correlated to e.g. environmental conditions than to
relationships between the groups (e.g. Peristome reduction or length of
the seta, just to name a few). I see the molecular based phylogenies as
a chance to uncover the (un-)reliable characters. Perhaps A,B and C are
not that extremely differing any more when we ignore the unreliable
characters?
Cheers
Volker
*******************
Dipl.-Biol.
Volker Buchbender
Clara-Viebig-Str. 5
01159 Dresden
Germany
BRYONET
Hi Johannes,
I agree; systematics is at its most exciting right now. The one
thing I would add is the caution that molecular data have homoplasy
also, and thus are not always reliable either. The problem with
traditional systematics is its methodology (i.e, a non-cladistic
approach, and reliance on only a few selected characters). The
problems experienced by traditional methods doesn't mean that
morphological characters are somehow more suspect. Our best approach
in the future is to integrate multiple sources of data: nucleotide
sequences from a number of unlinked genes, morphology, and genome
structure, to get a complete picture of relationships.
Best,
Brent
BRYONET
In some of the messages it appears as if molecular and morphological data are
considered fundamentally different for 'species' definition and classification
purposes. I believe Brent already pointed out that this is not the case; both
kinds of data can be used for phylogenetic reconstruction, and can in principle
yield results similarly useful for defining units and understanding how
different entities are related to each other. The main difference is that
molecular methods produce much more data than we can ever hope to do with
morphology. Even so, there are cases (yes, they do occur) when morphology
reveals phylogenetic signal that molecular evidence so far fails to recognize or
contradict. Thanks to the molecular data, we rapidly accumulate evidence that
many patterns of relationships among individuals, populations, etc. (e.g.,
recombination / hybridization), that we earlier saw only rarely and when they
affected phenotypically expressed characters, are more common than m
ost of us (including myself) perhaps thought. This needs to be considered in
our 'species concepts' as well as in our classification of 'species', because
this tells us something about how evolution has worked and how the various
entities are related to each other. Looking beyond that, a classification that
reflects phylogenetic history is more informative than other classifications and
therefore provides other biological sciences with a better basis for their
hypotheses as well as for their interpretation of various phenomena. This said,
I am the first to admit that I see problems with translating all known patterns
of relationships into names useful for every purpose. Names are our way of
summarising what we see and understand, and can therefore not perfectly cover
all aspects.
One thing in the debate I have some problems to understand is the statement by
Richard that "If one taxon, that is, one evolutionary entity, can appear in two
different molecular clades, how might this affect the use of named clades in
evolutionary research?" Is it not so that if one taxon appears in two different
clades, we have actually got two evolutionary entities, and they should be
treated as such? How can two separate lineages be one evolutionary coherent
entity? I would assume that members of evolutionary coherent entities by
definition must exchange genetic material among individuals at least
occasionally, or they can hardly be called coherent. An exchange of genetic
material leaves traces in the molecular pattern (and more rarely in morphology),
and then we have of course no longer independent lineages. Sometimes, what first
appears as odd molecular patterns can be clarified by a deeper study of the
morphology (or ultrastructure, physiology, habitat preferences, etc
.), as Volker pointed out, but in other cases we may have to accept that the
molecular patterns are not reflected in morphology.
Lars Hedenäs
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BRYONET
The thread of discussion seems to be wavering into a "what is a
species?" exchange. Let me lob one more query about monophyly and
paraphyly.
Take an extreme paraphyletic situation just for discussion purposes:
((AB)C . . . where A and B are terminal on a clade and C is just below
them (as nearest neighbor). A and C are exemplars of one species. B is
an exemplar of a different family.
How shall we classify this admittedly extreme example? A and C make a
paraphyletic group. (1) We could make A, B and C all families, which
makes three monophyletic groups. (2) We could sink family B into the
single species represented by A and C and make one monophyletic species.
(3) We could describe A and C as different "cryptic species" and reduce
B to a third species, all three in the same genus. (4) Something else?
Three different genera?
How does this get across evolutionary information?
Is this different from the common case when A and C are the same genus
and B is a different family or even a different genus? How? If species
are so sacrosanct and different from genera that they cannot be used in
the above example, then why are they commonly split as "cryptic"?
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Paul Wilson's weighing in on the side of the Phylocode is, I believe,
opportunity for me to repeat the evolutionary content of my objections
to monophyly in classification:
"My argument is that monophyletic taxa or lineages commonly have no
evolutionary coherence. Evidence is the "massive homoplasy" or fully
cryptic taxa (species, genera, families) that are being uncovered when
more exemplars are molecularly examined. Monophyletic taxa have
artificial integrity, much as alphabetical classifications are very
attractive for their intellectual and practical simplicity, and value in
advancing science. What happened to evolution in classification?"
If one taxon, that is, one evolutionary entity, can appear in two
different molecular clades, how might this affect the use of named
clades in evolutionary research? Pretty badly, I imagine. Monophyly has
phylogenetic information (tree-thinking, clades of molecular genetic
continuity and branching) but not necessarily evolutionary information
(e.g. when generitically isolated but evolutionarily coherent entities
are split among two or more molecular lineages). There is much evidence
for such in "massive homoplasy" and fully cryptic taxa at all taxonomic
levels. Paul Wilson' leap of presumption is in his words:
" Many of the things that have been given species names (and names at
all taxonomic ranks) are not monophyletic by contemporary definitions.
Other species have arisen out of part of them and left them behind.
There is overwhelming evidence for many cases of nominal species
containing uncountable numbers of indistinguishable long-isolated
lineages and excluding one or more divergent lineages that are nested
within. The way in which we go about discovering undescribed species and
revising nominal species boundaries does NOTHING to ensure that the
things we give Latinized name are monophyletic."
Why enforce monophyly? It is not a pattern of evolution but of generic
continuity, and should not be central to classification. Such continuity
is demonstrated in paraphyly as well as monophyly.
*****************************
Richard H. Zander
*****************************
------------------------------------------------------------------------
BRYONET
Please allow me to continue this discussion. I begin with a tribute to
Wilf Schofield. His passing marks the end of an era of bryology in
North America. Wilf has been my most significant bryological mentor. I
will miss him sorely.
We never discussed species concept because we had essentially the same
species concept and didn't need to. Wilf specialized in biogeography;
the units he mapped are the same kind of species I write keys for and
make inventory lists of, which I try to teach the next generation to
master.
I mis-spoke earlier when I suggested that I held a "modified
biological species concept." I didn't realize that these terms would
bring in a load of theoretical baggage which I do not fully embrace.
It would be far better for me to say I maintain a traditional species
concept. It is not entirely a scientific concept in that there is a
subjective, intuitive element to the traditional species concept. It
is not easy to articulate this to young biologists trained in
biochemistry and phylogenetics. The students in my taxonomy class who
have the most difficult time with species are those steeped in math
and chemistry. They like hard edges, clear definitions, to the
phenomena they want to learn. I would explain that species are like
rain storms. Rain storms are real things, but they have fuzzy edges
and are not always distinctly separated. Like species, rain storms are
generated in different ways and have different persistence in time.
Species, like rain storms, are part of a continuum only if one is
inclined to see continuous process as necessarily defining a
continuum. People like me see distinct storms in the atmosphere and
distinct species in the forest.
Traditional species are those collections of organisms which we, as
human beings, can distinguish (with reasonable consistency) using our
senses. The core definition of a traditional species is morphological
distinctiveness. Traditional species are very similar to the "kinds"
of biblical terminology, "created kinds" to a creationist. I would not
have trouble teaching a creationist to identify the species of moss in
our region. Although having a concept that is acceptable to
creationists is referred to disparagingly by some scientists, it
emphasizes the fundamental, intuitive aspect of the traditional
species concept. Folk taxonomies very often have species concepts that
are entirely congruent with the traditional species concept. David
French demonstrated that the Warm Springs Indians are able to
distinguish every single species of Lomatium, a "difficult" genus of
flowering plants, that western scientific taxonomists recognize. Jared
Diamond has written insightfully about similar folk taxonomies.
Learning to recognize traditional species is most readily transmitted
by direct instruction. I have even suggested that traditional
taxonomists are neo-shamans in western culture because much of the
knowledge is inarticulate. We detect smells and visualize forms for
which humans do not have adequate terminology. I can point out the
characters to a student or friend at my elbow but cannot describe them
in English or Latin. The consistency by which we use this knowledge,
across cultures, convinces me that it is a valid body of knowledge,
that traditional species are real entities. The notion is suspect to
many scientists, however, particularly those who adhere to the dictum
"if it ain't quantified it ain't science!" My reply is, if you're
studying nature you're doing science.
The traditional species concept is something that we adopt as humans
and in which we as scientists find a great source of inquiry. Here is
where scientific discussion begins. What Darwin attempted to do, with
considerable success, was provide a scientific explanation for how
(traditional) species came to be. Natural selection covers a lot of
cases. But not all.
It is proper to appreciate that the species we recognize with the
traditional species concept are not at all uniform. Ownbey claimed
that Edgar Anderson constantly reminded students: different things
evolve in different ways. Some species are differentiated by
genetically fixed reproductive isolation (more common in animals than
plants) and some by extrinsic reproductive isolation. Some species are
symbiotic and some are parasitic. Some species are characterized by
rapid change over time and some are characterized by stabilizing
selection. Some species are monophyletic and some species are
paraphyletic. Some species are variable and some are stenotypic. Some
are rare and some are common. Some are phylogenetically isolated and
some are part of a species complex. Some species have had reticulate
ancestry, while most have a strictly diverging genealogy. In some
cases, because of the limitations of our senses, some traditional
species are a mixed bag of genotypes that all look alike.
There is no doubt that phylogenetics is having a huge impact on
classification above the species rank, an impact that I appreciate and
attempt to incorporate into my work. Much of this discussion has been
about exactly how this is to be done. Because of the nature of my
situation, however, I cannot make serious contributions to this field.
I work in a home laboratory where I do not have facilities to extract
DNA and do not have funds to send the DNA for sequencing. When I find
a new species, it will be impossible for me to give it a phylocode
name because of this. I'll photograph it and give it a binomial. For
this reason, field botanists like me are likely to continue to rely on
a traditional species concept, traditional classification, and our
traditional system of nomenclature, and teaching by contact as much as
by writing.
And, from time to time, going hiking with those crazy cladists.
David H. Wagner, Ph.D.
Northwest Botanical Institute
P.O. Box 30064
Eugene, OR 97403-1064
davidwagner@mac.com
541-344-3327
BRYONET
Dear fellow bryophyte enthusiasts,
I just cannot resist throwing in my two cents on classification and
evolutionary biology. I do a little bit of work on bryophytes, but my
main teaching duties have been in evolutionary biology. Chatting with
bryophyte enthusiasts often makes me want to correct their evolutionary biology,
but I usually try to restrain myself, to listen more than to talk. The
discussion that Zander has brought up has the potential to generate much light
on subjects that many would do well to have illuminated. Of course, there's also
a danger of some frictional heat, but bryologists are all friends. And for
people who are coming at bryology without the background in terminology, I guess
they can ask questions if they want to learn more.
Zander brings up many really excellent topics of great interest to evolutionary
biologists. Many of his insights allow for some clarification after a little
rewording.
1. Conservatism of traits is a major feature of evolutionary history.
At all levels in the hierarchy of diversity novelties arise and then some of
them become characters that have gotten locked or nearly locked in place and
then don't subsequently change much. Perhaps this is because the lineage enters
an adaptive zone or a developmental mode where stabilizing selection tends to
make deviants less fit.
2. Mayr made many contributions to understanding evolutionary biology, including
a great deal of writing on the origin of reproductive isolating barriers, a
process very widely referred to as "speciation" ever since Mayr. A number of
people regret that the label contains the root "species" in it. The same regret
applies to "the origin of species" as referred to by Darwin, and to "species
concepts" as referred to in every evolutionary biology text.
"Speciation," "the origin of species," and "species concepts" are of
huge interest to evolutionary biologists - really the holy grail of
my field - but they are rather crudely related to the nominal species
of taxonomists and only crudely related to the twigs of the phylogeny
that may be named. One can regret Mayr's and Darwin's semantics
greatly (call those semantics evil) while still building on the
substance of their views. For example, Darwin went to great lengths
to illustrate that two divergent races can differ to any degree, that
the level of distinction we call a species boundary is in some cases
miniscule and in other cases very great with various cases having
amounts of divergence insensibly in-between. Mayr added greatly to
our understanding of the origin of diversity, but his and Darwin's
choice of words does cause mischief for most students of evolution
sometime during their studies.
3. Many of the things that have been given species names (and names
at all taxonomic ranks) are not monophyletic by contemporary definitions. Other
species have arisen out of part of them and left them behind. There is
overwhelming evidence for many cases of nominal species containing uncountable
numbers of indistinguishable long-isolated lineages and excluding one or more
divergent lineages that are nested within. The way in which we go about
discovering undescribed species and revising nominal species boundaries does
NOTHING to ensure that the things we give Latinized name are monophyletic.
Given all this, I more than sympathize with Zander's frustration and
I admire his depth of knowledge. As a matter of degree, my frustration is worse
closer to the species level and less acute further up on the major branches, but
it is really only a matter of degree. Given the great amount of interest I have
in many of the features of evolution that Zander points out, perhaps he will
find it heartbreakingly ironic that I end up using the same headlight as
Mishler. (I think these guys are not so far different in their first principles.)
There is a great cottage industry that is inferring the tree of life
with its divergent lineages, its reticulations, and its display of
convergence, reversal, and parallelism. This great cottage industry
uses many statistical methods that are being improved and invented
every year. The data that go into inferring the history of the tree
are varied, including a great many lines of molecular evidence,
morphology, ecology, geography, in some groups fossils. Although I
personally spend little of my time on the grunt work of these
phylogenetic researches, and although if I were spending money I
would spend a lot greater proportion on old-fashioned taxonomy near
the species-level, I can't but be wowed by how much progress is being
made on phylogenetics.
Now, I cannot be wowed and then at the same time deny phylogeneticists the
prerogative to name the branches and twigs of the phylogeny when well supported.
There is no stopping them, and they shouldn't be stopped. They should be
encouraged. The research is SO MUCH MORE VALUABLE if clades are named. It should
be noted, that this research is indeed very valuable. If one has a phylogeny,
then many of the topics that Zander brings up can be evaluated more
rigorously. If you try to use a pre-phylogenetic classification,
there are terrible statistical problems. If you want to learn about
adaptive zone, the co-option by development of genetic cascades, the
reason why some groups are diverse and others poor in diversity,
biases in the direction of evolutionary shifts, how climate changes
have spurred on speciation, etc., etc., etc. - you will do much
better with a phylogeny than with an old-fashioned evolutionary
classification.
So, I want a phylogenetic classification. In that context, ranks can
only be the crudest of designators and trying to maintain the rule
that "families cannot be in families, genera cannot be in genera"
will cause endless instability in the usage of names as we gradually
resolve the phylogeny better and better. For this reason I want the
establishment of a sensible phylocode, which is well underway. And I
think we should role up our collective sleeves to get the well-resolved branches
named. I don't think any of the phylotaxa should have -aceae or -ales at the
end. Yes, there will be some borrowing of names and parts of names that evoke
familiar taxa, but in general a reader must be able to know when an author
intended a name to be the name of a whole clade (and believed s/he had good
reason to believe it was) versus the names we currently have. I advocate having
two classification systems: the one we currently have, updated as people
see fit, with crude ranks and no attempt at monophyly at any level
(but especially not at the species level), and a new classification that has no
ranks at the species level or any other level.
The new classification will not instantly obliterate the old one. I
don't know if the old one will eventually fall out of usage. Maybe or
maybe not. We still seem to find a use for paraphyletic groupings
like Reptile, Invertebrate, Algae, and Bryophyte, so perhaps we will
still find a purpose for Scrophulariaceae and Acrocarpae. I do
predict that the new classification will be used. It will allow one
to put into words and remember that which otherwise could only be
presented graphically. There will be absolutely no stopping the
vertebrate taxonomists. Ibid. on those interested in the dynamics of
macroevolution. You could call the phylogenetic classification a
"special single purpose" classification - I wouldn't mind - but it is
a purpose of huge utility and central interest. In fact, if anyone is
left who wants to revamp our received evolutionary classification, s/he will
surely use the phyloclassification to appreciate such things as (1) which
characters are conservative where and which are homoplastic where, (2) branches
that appear long with a re-organization of how the organism does business and
which branches are short with ancient cousins still doing nearly the same thing,
and (3) the deep homologies that tread between seemingly disparate organisms.
Most respectfully,
Paul Wilson, Professor
Department of Biology
California State University
Northridge, CA 91330-8303
818-677-2937 FAX: 818-677-2034
For printable reprints: https://www.csun.edu/~hcbio028/cv.html
For pictures of bryophytes: https://www.csun.edu/~hcbio028
To listen to my like-radio show: https://www.csun.edu/~hcbio028/=20
EvolutionReport.html
BRYONET
Hi Richard,
Just a couple of comments here -- the monophyly concept I was talking
about is Hennig's -- it isn't recently arrived on the scene. And the
classification isn't theory-free; it is based on phylogeny and thus
has much evolutionary content. Phylogenies can be and are used these
days to study all aspects of evolutionary, developmental, and
ecological processes. But no need to repeat the literature here....
The important point is that bryological systematists need to continue
(and increase) our production of sound phylogenies incorporating
morphological and molecular data, and to reflect these results in
phylogenetic classifications. Researchers in all these new areas of
comparative biology and conservation are depending on us. And
perhaps most importantly, it is a tremendous source of new support
for our field!
Best,
Brent
BRYONET
Hi Richard,
You raise an important but huge issue. Too much for an email
discussion, but there is considerable literature if people are
interested.
You're right that complete reciprocal monophyly in all alleles in a
genome takes a long time, and perhaps never happens if occasional
horizontal transfer occurs. For example, Homo sapiens is not yet
reciprocally monophyletic with respect to chimpanzees, and we think
we are a pretty "good species." Bits of DNA in completely sequenced
plant genomes (including Physcomitrella) look like they came in
horizontally from other branches on the tree of life. So when people
like me talk about monophyletic taxa at any level, we are not talking
about monophyly in every single gene in that taxon. It's
complicated, for sure!
Best,
Brent
--
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
E-mail: bmishler@calmail.berkeley.edu
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
BRYONET
Well, I don't agree, Brent.
My argument is that monophyletic taxa or lineages commonly have no
evolutionary coherence. Evidence is the "massive homoplasy" or fully
cryptic taxa (species, genera, families) that are being uncovered when
more exemplars are molecularly examined. Monophyletic taxa have
artificial integrity, much as alphabetical classifications are very
attractive for their intellectual and practical simplicity, and value in
advancing science. What happened to evolution in classification?
How can you say Mayr was evil when phylogenetics is based on gradualist
evolution and the Biological Species Concept? You can't condemn the New
Synthesis then defend a System based on certain of, at least Mayr's,
central concepts.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Following Brent's discussion, "monophyly" is now a moving target, with
different definitions. One of them is resistant to my (and apparently
others') complaint of illogic.
If shared ancestors are now (by some anyway, including Brent) viewed as
having "special status" and not involved in definitions of monophyly,
then not only is the evolutionary information at the crown of a clade
excised from classifications (e.g. synonymizing a family derived from
another family), but the evolutionary information as it applies to
classification is also excised from all other parts of the cladogram.
This synchronic definition is what Hennig suggested we do, according to
Brent.
Apparently synchronic means ignoring theories of evolution, such that a
classification is theory-free.
What we are left with is non-ultrametric cluster analysis based on
nested sets of advanced traits. The relative "advanced" status of traits
is okay, since (in my opinion) clades are okay for what they are, since
there is nothing wrong with parsimony analysis are a way to group taxa
(morphologically) or follow genetic continuity (molecularly), but
eliminating the evolutionary information conveyed by morphological
traits and the unique, not phylogenetically informative morphological
traits that demonstrate wide evolutionary divergence is where the flaw
in phylogenetic classification lies. Again we have classification that
is not evolutionarily based, but phylogenetically based.
Once, I think most of us mainstream taxonomists thought phylogenetics
helped introduce more evolutionary information into classifications. To
some extent, parsimony analysis of morphology did, in my opinion. But
now, evolutionary information is being excised and we are poorer for it.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
That all new species or sister lineages will eventually undergo
reciprocal monophyly may be an unfortunate assumption that underlies a
major flaw in phylogenetic classification. Reciprocal monophyly occurs,
correct me if wrong, when speciation occurs and the two genetically
isolated lines gradually diverge, pupping off their own new species.
Reciprocal monophyly may be slow to occur when there is backcrossing or
later hybridization, but the two lines gradually diverge sufficiently
that they are entirely distinct.
I think that reciprocal monophyly may not occur, however, when two (say,
geographically or otherwise genetically) isolated populations remain
morphologically static, undergoing the same normalizing selection,
although both accumulate different non-coding or otherwise minor DNA
changes. These isolated groups may pup off their own quite different new
species but remain evolutionarily identical (identical traits involved
in selection), and are extant as "surviving ancestors". Thus, at least
two independent lineages of the initial split remain resistant to forces
that encourage reciprocal monophyly: mainly anagenetic, gradual
evolutionary change. Even a single lineage, if it remains static while
producing daughter species confounds assumptions of reciprocal
monophyly.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Hi all,
Delineating evolutionary groups is difficult simply because they are
often gradual and in this aspect, I agree with Lars.
I think that we should keep the concept of species more plastic and
flexible, leaving open the question of resolution with respect to
"true" species boundaries, particularly when we estimate genetic
variance of quantitative traits indirectly from the rutinely used
molecular markers.
Keeping in mind that species differences have usually a polygenic nature
and often different sets of genes epistatically interacting underline
biologically important morphological traits or hybrid sterility, this
extrapolantion may be a big lottery. Sometimes we win. Sometimes we
lose. Regardless of these preliminary results, we should keep track of
moving files anyway.
Regards,
Iwona Melosik
Department of genetics
Adam Mickiewicz University
Poznan, POLAND
Here is Brent's paper, "Species are not uniquely real biological
entities." It came through in the wrong format to go with his earlier
message.
BRYONET
Hi Jon,
Reproductive isolation is certainly important biologically, but we
who work on plants realize that there is not one magic point at which
ability to interbreed suddenly goes to zero (unlike the zoologists
who insisted there was such a point). In plants (and it turns out in
most animals also), the potential to successfully interbreed
gradually trails off as one looks at more and more distantly related
populations. Thus even with respect to interbreeding, species are
not different in some special way from levels above and levels below.
Cheers,
Brent
--
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
E-mail: bmishler@calmail.berkeley.edu
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
BRYONET
i THINK I believe that species are more real than other taxa
(levels ...). As the population geneticist Jody Hey has pointed out,
the (time) point at which two taxa become reciprocally monophyletic
does not identify a moment of any biological import. The time at
which two species become reproductively isolated is important because
only then can they become reciprocally monophyletic.
J
Jonathan Shaw
Department of Biology
Duke University
Durham, NC 27708
Phone: (919) 660-7344
FAX: (919) 660-7293
shaw@duke.edu
BRYONET
I am moved to offer a comment following that made by Lars Hedenas (31 October).
The discussion on species, genera, families, evolutionary relationships, etc.,
has for the most part been written in terms that are specific to the realms of
the molecular geneticist and, I dare to add, largely incomprehensible to many
mere mortals (a group to which I align myself) - but, then, that is applying a
classification not only to myself but others and perhaps I should have assigned
myself a number - and a different number to each and everyone else!!
Molecular characteristics are just ONE of many characters we can use to classify
organisms. In the field, I do not use DNA sequences to identify what I am
looking at. I answer the innate call of the human species to classify or to
sort everything into some sort of order - to lump like with like, to make order
out of chaos.
To assign a number to every individual ignores, it seems to me, relationships,
notwithstanding the fact that Lars asserts that in Nature everything is more or
less part of a continuum.
As Nature deals in variation, Type species represent only one part of that
variation and perhaps in Botany we should take note of the standards applied by
Entomologists - at least 20 specimens of an insect are needed to draw up a
species description so that variation can be ascertained and described and also
the differences between male and female can be part of the morphological
description.
I walk my dog each morning accompanied by the Tasmanian Forensic Pathologist.
We have many and varied discussions and he confided to me the other morning that
DNA shows considerable variation - the result of random mutations. This makes
his job more difficult than it might be and emphasises the point that DNA is
not, perhaps, the definitive answer to everything.
Who knows if the species, let alone the individual assigned to a particular
species, in these molecular classifications is, in fact, a "good"
representative. If the Phylocode becomes the accepted norm, there will be great
scope for molecular biologists - they will need to sequence every single
individual in order to come up with a classification that indicates relationships.
Somewhat tongue in cheek, perhaps, but I intend to retain my faith in
morphology, ecology, and classical taxonomic methodology.
Prof. Rod Seppelt,
Principal Research Scientist,
Australian Antarctic Division,
Channel highway,
Kingston 7050,
Tasmania, Australia
ph: +61 (03) 6232 3438
FAX: +61 (03) 6232 3449
e-mail: rod.seppelt@aad.gov.au
---------------------------------------------------------------
BRYONET
It seems like it is time to add some more hard data in the species concept
debate. The purpose with this is not to say that different species concepts
cannot be valid under specific conditions or for special purposes. I just want
to underline that when I experience (basically!) a continuum with some breaks
this is as much based on observations as what we intuitively see when we are out
in nature, only that it is observations of molecular and morphological patterns,
from below to above the species level. When we start looking into the molecular
structure of what we usually call 'species' and complexes of closely related
morphologically defined 'species', we actually find a lot of interesting and at
first startling patterns that seem to contradict our intuition regarding what a
'species' is. However, I believe these patterns justify a somewhat different,
but as pragmatic interpretation, than more traditional concepts regarding how to
mentally organise individuals, populations,
etc., into units that we may call 'species' or not. I think a number of
examples from among the mosses may be helpful to describe the span in how
variation below to just above the traditional 'species' level appears to be
organised, even though I will not get into details regarding which molecular
markers, etc. were used.
Scorpidium scorpioides is a well-known and widely distributed wetland species,
where we find both quite some variation and recombination within a
morphologically well defined species and could probably feel satisfied with the
traditional species concept (cf., Taxon 57: 121-130; 2008). If we look at the
equally well morphologically defined, very closely related S. cossonii (same
paper), we also find a lot of variation, no evidence for recombination, BUT the
molecular pattern suggests that this, as morphologically defined, is
paraphyletic. Scorpidium scorpioides is nested within S. cossonii, and in this
specific case it does not appear as if incomplete lineage sorting is the reason
for the found pattern. Thus, the situation parallels that found at higher
taxonomic levels. Both these Scorpidium species, as morphologically defined,
make sense from a biological point of view, since they have, i.a., different
habitat preferences and partly different geographical distributions. On t
he other hand (as will be seen in a forthcoming paper in Plant Systematics and
Evolution), the molecular variation makes as much sense biologically if the
morphology-based concepts of these two species are disregarded, namely when
interpreting the history of this complex, sine genotypes that appear ancestral
in the S. cossonii-scorpioides complex are restricted to specific climatic
regions from which other, gradually more and more different genotypes have
colonized most of the current distribution areas of the 'species'. Who can tell
whether an interpretation as a 'continuum of increasingly different genotypes'
or a traditional species concept is the more meaningful in this case?
Next, consider the situation in Antitrichia curtipendula s.l. (Botanical Journal
of the Linnean Society 156: 341-354; 2008). In this complex, we find (1) two
molecularly well and morphologically somewhat, but clearly separated species, A.
curtipendula and A. gigantea, the latter restricted to western North America.
Within the widespread E North American-Eurasiatic-African A. curtipendula we
find (2) two clear groups of genotypes, or 'cryptic species' (?), that differ
from each other in two mutational events. Within one of these two groups
recombination seems to have occurred, but not in the other. Within the latter,
we find (3) that the tropical African populations are unambiguosly
differentiated from the rest in one mutation (and possibly morphologically). If
the African populations are recognized as a taxon this would, however, make the
rest of A. curtipendula s.str. paraphyletic. Whereas the recognition of A.
gigantea as separate could be interpreted within a traditional species
framework, the situation for A. cutrtipendula is more difficult. We have two
slightly differentiated cryptic E North American-Eurasiatic lineages, one of
which has a more restricted distribution within the total distribution of the
other, and a separate tropical African lineage nested within one of these.
Again, one could interpret Antitrichia curtipendula s.str. as a single species
and be happy with this, or one could admit that there is a lot of additional
hitorical or phylogeographic information to be gained from recognizing the
variation that it is actually present.
The third example is Hamatocaulis vernicosus, where we have two molecularly well
differentiated 'cryptic species' within what we morphologically define as a
single 'species' (Plant Systematics and Evolution 268: 131-145; 2007). In
Europe, one of these 'cryptic species' seems to occur throughout the continent,
whereas the other one is found only south of the northern boreal zone. Is this
one 'species', that everyone can recognize in the field, or is it more
meaningful from a biological and conservation point of view to recognize two
'species' with different histories, frequencies, etc., or maybe a 'species
concept' does not describe the situation at all?
As a fourth example, consider Drepanocladus aduncus, which some researchers
until very recently divided into three 'species' based on morphology. Molecular
variation shows that we actually have a single, albeit very variable lineage
(Journal of Bryology 30: 108-120; 2008). Again, the infraspecific variation
appears correlated with meaningful geographic patterns. Thus, are the
intuitively interpreted three 'species' better than the single lineage revealed
by the molecular variation, for biological and conservational issues?
As a fifth and last example, within 'genera' such as Homalothecium (American
Journal of Botany 95: 720-730; 2008; mscr. in prep.), Isothecium (Molecular
Phylogenetics and Evolution 42: 700-716; 2007), and Sciurohypnum (forthcoming
paper in Taxon), it has recently been shown that (1) what we interpret as good
'species' based on morphology sometimes exchange genetic material in various and
sometimes very surprising ways (Isothecium), and (2) specimens that are
intermediate between morphological 'species' both molecularly (partly as a
result of recombination) and sometimes also morphologically do exist. What is a
good 'species' in such cases, and how are they compared with each other and
other, 'better' defined ones in terms of their contribution to the biodiversity
(including function in ecosystems).
Rounding up, I fail to see why the variation below to just above the 'species'
level should be treated so fundamentally different from the variation seen at
higher levels. The lineages we now recognize as 'families' started as less
distinct lineages corresponding to what we now call 'genera', those recognized
as 'genera' started as 'species', and those recognized as 'species' as
'populations' or individuals, didn't they? We are talking about the same gradual
process of lineage differentiation and individual or lineage extinctions all the
way, aren't we?
Lars Hedenäs
BRYONET
Dear all,
Dave and I are old friends and colleagues, having argued these issues
at many SO BE FREE forays! Speaking of which, everybody come next
year to the Sierra Nevada, 24-27th March, 2009, see announcement at:
http://ucjeps.berkeley.edu/bryolab/trips/sbf_2009.html); we can
continue these deep discussions over wine and a microscope with real
plants...
So no disrespect intended, Dave is truly a great field bryologist,
but his view that species are special is a minority opinion among
botanists (it is a import from zoology...). The first evolutionary
botanist, Charles Darwin, had it right. Attached is another "in
press" paper, from a book edited by Robert Arp and Francisco Ayala
(one half of a debate on this issue), that outlines the noble
botanical point of view stemming from Darwin, and the evil zoological
point of view stemming from Mayr... :-)
I argue that all taxa are real, if properly recognized as
monophyletic groups. So are species, but not in a special way...
Dave and I agree that ties to the entire suite of biological data are
an important property of a good classification. I just add that this
extends to the whole rich hierarchy of nested taxa making up the tree
of life
Best,
Brent
BRYONET
I am going to jump into this discussion to provide the perspective of
a field botanist. That's what I call myself. Rod Seppelt would
recognize me as a mainstream taxonomist. Brent Mishler, as he writes
in his forthcoming Taxon paper, knows me a pragmatist who confronts
theoreticians.
I have a strong academic background (which includes a 17-year
university post) but the latter part of my career has been primarily
doing field research with ongoing teaching supplementary. It is from
the field botanist's perspective that I offer a contrasting critique
of Lars Hedenas' view that everything in nature is part of a
continuum. My experience and training leads to a differing
interpretation of what I see in nature. A species concept is at hand.
When I return from a job, a significant part of my report is a simple
species list. When I report that there are 78 species of bryophytes in
watershed A as opposed to the 52 species in watershed B, I am
confident I am providing meaningful information, subject to critical,
independent verification. What I recognize as a species is very clear
to me as well as those who receive my report. They can use this
information to help decide if watershed A or B is worth more
investment of management attention. If alpha biodiversity is the sole,
legal criterion for attention, watershed A gets the funding. Nobody,
not even a lawyer, will contest this decision.
Every name on my species list additionally provides a link to its
entire suite of biological data. All supplemental data, such as
abundance, microsite character, reproductive potential, or
significance in the ecosystem, are clearly tied to the species name I
use. In other words, when I say I have found Brachythecium frigidum in
a small drainage of watershed A, it means (in southwestern Oregon)
that this small drainage contains a permanent stream. A permanent
stream is important to fisheries. If a fisheries biologist can learn
to recognize Brachythecium frigidum in the field, he or she can make
an on-the-spot, seasonally independent, assessment as to the nature of
that stream. There are practical applications, e.g.: no logging across
permanent streams but maybe logging in valleys with intermittent
streams when the drainage is dry.
The species I recognize, whether bryophyte or vascular plant, are
real. They have been recognized by adepts since before written
language. We pass on identification skills from one generation to the
next. (The lineage of my teachers reaches directly back to Linnaeus
and before.) The species we name are natural aggregate entities whose
existence demands a biological explanation. They are facts to which
the theory must fit; we cannot (like creationists) try to fit the
facts to the theory.
Why are species so easy to recognize? Evolutionary theory has shown
that species are the aggregate units upon which natural selection
acts. My own concept is a modified biological species concept;
reproductive isolation is characteristic of most good species. The
small number of entities which don't fit this concept are proof that
species are not immutable, that evolution is an ongoing process and
not just a theory to explain the past. This number is less than the 5%
confidence interval. In western Oregon, I can positively identify over
99 % of the specimens I bring in from the field. There is a BIG break
in the continuum between species and the first rank in our taxonomic
hierarchy, genus.
Now, if I were to say there are 14 genera in watershed A and only 11
genera in watershed B, Brent's can of worms is opened up. My taxonomic
opinions will influence these numbers. Here is where I admit Lars'
continuum shows its application. What defines a genus does not have
the intuitive sense of a species, nor it does not seem to have any
biological sensibility, either. My mentor, Marion Ownbey, used to
repeat constantly, "There is no objective means of determining rank in
a hierarchy." In this regard I appreciate the phylocladist's dilemma.
My conundrum is not confined to theoreticians. Consider an imaginary,
plausible example.
Suppose I find a distinctive species of moss on rocks in a streambed.
I am confident it is an undescribed species. Its characters would lead
me to place it in the genus Racomitrium in the sense I have used for
most of my career. If I were to apply the taxonomy in the new
Bryophyte Flora of North America, it would seem to be referable to
Bucklandiella. I can't name a species without assigning a genus. This
is the Achilles heel of Linnaean nomenclature. What should I do? I
cannot see how the phylocode will help me. But the phylogeneticists
can help me learn if Bucklandiella is monophyletic and justify naming
in this genus, or show Bucklandiella to be paraphyletic or
polyphyletic (which it really appears to me) and I can relax and
describe a new species of Racomitrium.
To summarize, a species is biologically real entity. There is no
continuum between species and higher ranks in a hierarchy of
classification. A continuum characterizes classification ranks at
genus and above. A traditional hierarchy of classification is
extremely useful, in that it maintains reference to past literature
and helps teach students to learn the species. It organizes
information in an intuitive, if not strictly phylogenetic, fashion.
Phylogenetics can contribute to a refinement of our traditional
classification. The phylocode is largely irrelevant to a field
botanist's work.
David H. Wagner, Ph.D.
Northwest Botanical Institute
P.O. Box 30064
Eugene, OR 97403-1064
davidwagner@mac.com
541-344-3327
BRYONET
Hi Richard,
Interesting discussion, getting to some really important issues for
bryology. Here is a quick comment on your note:
There have been two different concepts of monophyly out there in the
literature since Hennig; the first a diachronic definition that
includes the ancestor in the group, worded succinctly like this: "a
common ancestor and all of its descendants." You correctly point out
that this definition leads to logical paradoxes, especially with
ranked classifications. Others have pointed this out in the
literature as well, including me.
But the second view of monophyly, Hennig's own, is a synchronic
definition, worded succinctly like this: "all and only descendants of
a common ancestor." I.e., the ancestor (if known) is not classified
with its descendants; it has a special status. This definition is
not subject to the problems you outline. There is further discussion
in the chapters I co-authored in the book "Species Concepts and
Phylogenetic Theory: A Debate" edited by Wheeler & Meier, 2000.
Best,
Brent
--
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
E-mail: bmishler@calmail.berkeley.edu
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
BRYONET
Dr. Kumar is clearly a mainstream taxonomist, like myself. What is a
mainstream taxonomist?
You know you are a mainstream taxonomist if you instantly reject a
proposal to change the Code of Nomenclature such that any new name is
illegitimate if, when used as a correct name, it would render another
group paraphyletic. A phylogeneticist would consider the proposal a
moment before deciding one way or another.
Kidding aside, I think mainstream taxonomists accept that exemplars make
up clades but exactly what each specimen implies is one way how we
differ from phylogeneticists. Mainstream taxonomists accept that
molecular phylogenetic analysis, assuming reliability, tracks genetic
continuity and isolation, but we differ in how continuity and isolation
is reflected in classification. Mainstream taxonomists accept that
classifications should reflect descent with modification as best
possible, but we feel taxa are what descend and are modified by
selection, not traits such as are individually mapped on a molecular
cladogram. We are happy with the new developments in systematics over
the past 30 years, except for the loss of evolutionary information
caused by strict enforcement of monophyly in classification, and the
glorification of morphological tree-thinking as anything more than a
form of non-ultrametric cluster analysis. (Well, this is my off-the-cuff
manifesto, and may not represent everybody.)
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Drs. Werner and Ros have a good point that different classifications address
different needs. In my opinion, however, this is not a case where, for instance,
alphabetical classification is good for organizing herbaria, the Phylocode is
good for phylogeneticists, and Linnaean classification is good for mainstream
taxonomists. I'm saying that monophyly fails by its own logic.
Dick Brummit has pointed out that if paraphyly is not allowed in classification,
taxa collapse into one species in one genus in one family. Here is my example:
Monophyly requires all exemplars implying any one taxonomic level to be
ultimately derived from one basalmost shared ancestor, and such ancestor is of
the same name as all exemplars (at some level, species, genus, or whatever).
Judging from diagrams of monophyly in definitions of the term, the ancestor is
definitely included in that taxon. This is most parsimonious in that only one
change at a given taxonomic level is needed. That is, in an (AB)C terminal group
with A and B in genus X, the shared ancestor of A and B is, monophyletically, an
extinct species in genus X, otherwise if the extinct shared ancestral species
were in a different genus, A and B in genus X would have to both derive from
that different genus, say Y. Two independent evolutionary developments of genus
X would be needed if the shared ancestor were a
different genus, which is less parsimonious.
However, if A and B in ((AB)C were different genera, the most parsimonious view
of their shared ancestor would be that it was either a species in genus A or
genus B, not in some third, unknown, hypothetical genus, which would require two
derivations of genus A and genus B from that third genus. If the shared ancestor
were either in genus A or genus B, only one derivation of a new genus is
necessary. In cladistics, every hypothetical extinct shared ancestor requires an
extra unnecessary speciation event to create that ancestor. BUT if one of the
sister taxa A or B is the same taxon as the shared ancestor, that taxon is
paraphyletic and the other sister group must be synonymized with it. This
applies to all bifurcations in a cladogram if monophyly were required
throughout, and the cladogram collapses. The taxon of the shared ancestor can be
guessed at by examining the next more basal lineage (the "nearest neighbor") and
seeing which sister group is more similar to that. That is
, is A or B more similar to C? If A, then B must be synonymized with A.
Example: In the Werner et al. 2004 (Plant. Syst. Evol. 243: 147-164) cladogram
of Pottiaceae, Pottiaceae s.str. is sister to an Oreoweisia-Pleuridium clade
representing both Dicranaceae (as Rhabdoweisiaceae in MPG III) and Ditrichaceae.
Because the nearest neighbor is Ceratodon, in Ditrichaceae, the shared ancestor
of Pottiaceae and Dicranaceae-Ditrichaceae is probably Ditrichaceae, which is
now paraphyletic. Thus, all genera of Pottiaceae should be sunk into
Ditrichaceae. (Given the few exemplars, this is just an example for
illustration, and the taxonomic identity of the shared ancestor is doubtless not
discoverable from this data.)
In the same cladogram, Pottia lanceolata and P. bryoides have a shared ancestor
most parsimoniously identifiable as Pottia, hence making the Pottia clade
monophyletic. The sister group of Pottia is Stegonia latifolia. The shared
ancestor of Pottia and Stegonia, if the one most similar to Desmatodon
latifolius the nearest neighbor, would be Stegonia, not an unknown third genus.
This minimizes the number of new genera created evolutionarily. By the logic of
monophyly, all species of Pottia need to be sunk into Stegonia.
If this seems extreme, in my opinion the problem is that phylogenetics is
founded on the reverse of what is commonly promoted as its best features,
monophyly and parsimony of explanation.
This does not mean that the Werner et al. 2004 cladogram is in any way wrong as
a cladogram. It does illuminate genetic continuity and isolation in the family,
and is a significant aid in classification along traditional lines. It is the
phylogenetic interpretations of what the exemplars imply that I think produce
something (MPG III) that is not even a specialized classification for a
specialized audience.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Hi Rod,
Hope all is well down under. I'm glad you bring up morphological
data; it is relevant to clearing up a common misconception:
Phylogenetic systematics in general, and the Phylocode in particular,
is not about molecular genetics per se. It is about monophyly,
classifying closest relatives together, and many kinds of data can be
used as evidence for hypothesizing monophyly including morphology.
Morphology has an important role to play in phylogenetics; I remain a
big fan of it (as does Lars)! So the crucial issue is not data
sources, but rather what is done with data.
Best wishes,
Brent
**********************************************************
Brent D. Mishler
Professor, Department of Integrative Biology
Director, University and Jepson Herbaria
Associate Director, California Biodiversity Center
Mailing address:
UNIVERSITY OF CALIFORNIA, BERKELEY
UNIVERSITY AND JEPSON HERBARIA
1001 VALLEY LIFE SCIENCES BLDG # 2465
BERKELEY, CA 94720-2465 USA
Phone: (510) 642-6810
FAX: (510) 643-5390
E-mail: bmishler@calmail.berkeley.edu
WWW: http://ucjeps.berkeley.edu/people/mishler.html
**********************************************************
BRYONET
Good idea Brent, to bring in the species concept as well in the discussion,
since this has bearings also on how we understand the higher taxa. To my mind,
'species' as they are usually understood, i.e., as some kind of entities that
could be intersubjectively described according to specified criteria, are as
much a constructed concept as the higher taxa. What actually is out there is
basically(!) a continuum from 'identical' individuals through slightly different
ones to more and more different ones, and so on up to the highest 'taxonomic
levels'. Due to different historical, spatial, genetic, or other factors or
constraints, many breaks in the continuum have occurred. Examples of such breaks
include extinctions of entire lineages and earlier representatives of extant
lineages, at all levels from individuals, populations, or 'species' to lineages
recognized at higher taxonomic levels.
The 'species' is a practical concept to describe variation and diversity in
nature. However, to focus too strongly on the 'species' concept and 'speciation'
(if focussing only at the species level) tends to block the mind from exploring
many of the patterns present out there, also regarding the higher entities
usually recognized to summarize the variation among the 'species'. Since I
believe that in nature there is really a continuum that has been affected by
numerous subsequent breaks, I am not sure that any species concept recognizes
entities that are directly comparable to each other any more than the currently
used higher taxonomic level entities. We simply need to decide what we need the
species concept(s) for. How does a specific species concept guarantee that, for
example, similarly large (in which sense) units, biologically / ecologically
equally 'important' functional units, or evolutionary equally significant
lineages are recognized as the 'species' that can subsequ
ently be used in comparisons of diversity, functional, and other
characteristics among areas, ecosystems, etc.?
Have a nice weekend, Lars
Lars Hedenäs
Swedish Museum of Natural History
Department of Cryptogamic Botany
Box 50007
SE-104 05 Stockholm
Sweden
ph: +46-(0)8-51954214
Try our searchable database to registered cryptogam specimens (English, Swedish,
Spanish): http://www.nrm.se/botany/krypto-s
Månadens kryptogam (Swedish): http://www.nrm.se/manadenskryptogam
BRYONET
Jon has countered my objections to the new online moss classification by
Goffinet, Buck and Shaw (let's call it Moss Phylogeny Group III) with
several important points. I will take these from last to first:
Apparently we must choose or compromise between genealogical
relationships and phenetic distance. I can't believe that Jon equates
the concerns of evolutionary taxonomy simply with phenetic distance.
Judging from his fine papers on population ecology and metapopulations,
he is quite familiar with macroevolutionary theory. This discussion is
not a reprise of the battles between pheneticists and cladists of the
70's, which the cladists won with a method that seemed to match
evolutionary theory better (parsimony).
Regarding capturing genealogical relationships, there is precious little
information on genealogical relationships in MPG III. The genealogical
relationships of the lineages is mostly back in the cladogram(s) on
which the classification is based. Long ago, cladists tried to put
genealogical relationships into classification by strict hierarchy of
ranks in a clade. For the three-taxon terminal group ((AB)C . . ., if C
is a genus, then the lineage (AB) is a genus and A and B would be each
subgenera. And so forth. Of course this was unworkable, both because one
soon runs out of ranks and because taxonomists would not put up with it.
If A is a genus, then it is a genus, not a subgenus no matter where in
the clade it occurs. Cladists caved in and now allow clades with exactly
the same taxonomic rank in all branches of a clade, such as a clade with
all species, or all genera (or implied genera since we are dealing only
with exemplar specimens), etc. This classification hides genealogical
information because there is no clue to position of a taxon on a tree.
Well, if genealogical subgenera can be promoted to genera if indeed they
are genera, why not to families if indeed they are families?
I think, correct me if wrong, that the only genealogical information in
the MPG III is the distribution of genera in families or families in
orders. This means that the classification gets across at most the
information that each family is a polytomy of genera. Each order is a
polytomy of families, etc. Where is the genealogical information on
position in a clade? Back in the cladogram, quite a different thing,
okay in its own right and place. This hiding of genealogical information
in a phylogenetic classification is, in addition, at the cost of hiding
any evolutionary information that conflicts with an insistence on
phylogenetic monophyly. Given this problem, surely cladograms and
evolutionary classifications with paraphyly can co-exist, separately,
and convey their different kinds of information?
Jon wrote: "this approach would mean that some members of the Pottiaceae
share a more recent ancestor with species outside the family than they
do with other Pottiaceae. Not good." The cladogram clarifies this with
exemplars, so why cripple the classification?
Jon wrote: "Ephemerum is simply a highly modified (morphologically)
member of the Pottiaceae clade." Simply? I see no comparative discussion
of morphology and biorole that may or may not distinguish Ephemeraceae
as a family. How about Splachnobryaceae? Is there any discussion of the
reasoning of A. Koponen on this issue? Clearly evidence of evolutionary
adaptation is ignored in MPG III by insisting that the evolutionary
classification instead match the phylogenetic cladogram, even though
even an approximation of such a match is impossible because strict
hierarchy of ranks has been quite reasonably abandoned by cladists.
The Phylocode apparently does create a classification with such a match.
I think attempts to wrench evolutionary classifications into a
phylogenetic mold, e.g. MPG III, are not helpful to understanding either
evolution or genealogy.
Jon wrote: "since many "good" species (defined morphologically or even
biologically [reproductive isolation]) may not have had time to reach
monophyly." This assumes gradual and continuing change, while there is
plenty of evidence of punctuational evolution followed by stasis of
morphology (like habitat tracking). The fact that there are many fully
cryptic species indicates that ancestral species (identified as shared
ancestors in cladograms), anathema to monophyly, may be extant.
Morphological stasis (while DNA continues to mutate) is governed by
stabilizing selection, which after all is the basis of taxonomy. A
living fossil confounds insistence on monophyly, and is not necessarily
revealed by polytomies in a morphological cladogram but will support
paraphyly or even apparent phylogenetic polyphyly in some cases.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
*****************************
BRYONET
Richard, and colleagues,
I always appreciate input, and I view the classification as an "community"
effort. I take responsibility for error and some judgments.
Some specific responses:
Ephemeraceae and Splachnobryaceae: the study by Goffinet et al. (2001,
Annals of Botany) and Goffinet & Cox (2000, Bryologist) suggest that
Ephemerum and Splachnobryum are closely related if not nested among
Pottiaceous taxa. One could doubt these results until further study and
retain the Ephemraceae and Splachnobryaceae as separate families, but there
is as little support for that (beside the morphological "distinctiveness")
as there is , as one could argue for merging them with the Pottiaceae. It
seems very much reasonable to me to consider these families as reduced
Pottiaceae. Maybe I am wrong. It would be worth mentioning that Micromitrium
and Ephemerum exhibit distinct patterns in spores germination, and
protonemal development, and that while Ephemerum exhibits a patterns
congruent reminiscent of the Pottiaceae, Micromitrium does not. We are
currently investigating this more.
Rhabdoweisiaceae: a group of genera placed in this family composes a
monophyletic group that appears to be sister to the Dicranaceae (excluding
some genera placed elsewhere). Whether two sister-lineages should be
recognized as two taxa or not is a question of preference. The argument that
the Rhabdoweisiaceae may lack a diagnostic character, may be true, and can
result from a) variation within the lineage, with apomorphies lost due to
reduction, or b) simply that we have not looked hard enough. The same
problem arises within the Splachnaceae wherein clades lacks diagnostic
features expressed by all members of the group. At present I suggest
recognizing the two families, thereby stimulating a critical investigation
of the characters, by exploring the complete -not merely the traditional-
character space (i.e., developmental, anatomical characters of the
calyptrae,...).
Lumping: the merging of a monophyletic taxon with the paraphyletic group
subtending it has been much debated. Such practice does not completely erase
"the effects of history on traits that respond to evolutionary forces" since
taxa of a rank below can accommodate that. Granted subfamilies,
subgenera,... are typically implicitly ignored and carry less importance in
our daily practices.
As I have said before I would welcome discussion on some of the decisions.
In response to the initial message I have received many comments, some can
be easily addressed others require that someone (myself here) makes a
judgment call. As I also said before, I would hope to find the time to
provide annotations to the classification, but the critical element here,
namely time, is a precious resource these days.
To simply "reject in the Goffinet, Buck and Shaw classification all lumping
and splitting that is based solely on enforcing phylogenetic monophyly, and
is not based on reasoned evaluation of the evolutionary importance of the
taxa involved" makes no sense to me, mainly because one's "evaluation of the
evolutionary importance of taxa" may be fairly subjective, and because that
hypothesis is, just a hypothesis as well, and while a gut-feeling that
something is wrong may provide the impetus for a reevaluation of all data,
and thus lead to a critical testing of all hypothesis, and be confirmed,
that feeling should not be the sole decisive factor. For example, the
merging of Coscinodon with Grimmia is based on the recent study by Hernandez
et al. (Mol. Phyl. Evol.) wherein the two species of Coscinodon are nested
each is a distinct clade of Grimmia, which prompted me to abandon the genus.
Recent discussions raise the issue of low taxon sampling, ...., all of which
are valid. Retaining the genus does, however, not inform us of evolutionary
importance of this taxon, in fact it is misleading. Now, there is a
possibility that there is a lineage that should be called Coscinodon, but
the circumscription of which should be revised.
We have made errors, as I acknowledged in the Goffinet & Buck (2004) paper,
with some changes in the classification due to misidentification of taxa in
phylogenetic studies, or other causes. There may be errors made by others,
in their work. The classification is a work in progress, and I urge
bryologists to raise issues that they have with aspects of the
classification.
I welcome comments.
Bernard
--
Dr. Bernard Goffinet
Associate Professor
Ecology and Evolutionary Biology
75 North Eagleville road
University of Connecticut
Storrs CT
06269-3043 USA
Ph: 1-860-486-5290
Fax: 1-860-486-6364
http://www.eeb.uconn.edu/people/goffinet
Check out the on-line classification of mosses:
http://www.eeb.uconn.edu/people/goffinet/Classificationmosses.html
BRYONET
One of the basic problems is that it is impossible to classify organisms
in a simple way that reflects all the biological complications behind
the surface. If you want all taxa to be monophyletic you loose important
information and if you admit paraphyletic taxa you loose other important
information. We are afraid that there is no simple solution to this
problem and have to admit that in our own work we did not follow a clear
line, partly because of opposed opinions within the coauthors of our
papers, partly - to quote Jon - because Â"life is full of compromisesÂ"
and for one reason or the other, we preferred one bad solution over the
other.
One additional problem is that different types of biologists have
different needs. If you are interested in reconstructing the tree of
life, you prefer monophyletic taxa. Maybe an ecologist prefers
paraphyletetic taxa, because they are more similar in their biological
niche requirements. If you are teaching, you prefer a relative simple
system that is easy to understand, and so on.
As a conclusion, we are afraid that our grandchildren will still be
discussing these issues. But the good thing is that with a little luck
some of us will be funded to do all the additional research that is
necessary to solve all the problems related with biological classification.
Olaf Werner and Rosa Maria Ros
--
Rosa MarÃa Ros EspÃn
Catedrática de Botánica-Professor of Botany
Universidad de Murcia
Facultad de BiologÃa
Departamento de BiologÃa Vegetal
Campus de Espinardo
30100-Murcia
Tlf: 34-968-364989
Fax: 34-968-363963
E-mail: rmros@um.es
BRYONET
Yes, of course all of this would stop with a rank-free classification
and final implementation of the PhyloCode. It is clear that the
hierarchical Linnean nomenclature and classification cannot reflect or
represent the phylogenetic lineages with any accuracy. Perhaps we
should make a clear distinction between a "descriptive" (Linnean and
morphology based) classification and an "analytical" one. The
descriptive taxa could consistently be cited in quotation marks
"Ephemeraceae" and they could be used in floras, keys etc. Monophyly
in "real" sceintific classifications is an absolute prerequisite
because it is their very basis!
Best regards,
Johannes E.
--
Dr. Johannes Enroth
PhD, University Lecturer, Bryologist
Dept. of Biological and Environmental Sciences
P.O. Box 65
FIN-00014 University of Helsinki
Finland
______
BRYONET
Hi all,
You anticipated me, Jon -- I was just going to say that these strange
artifacts that Richard refers to are due to constraints of the ranks
in the current nomenclatorial system, not due to constraints of
monophyly. Under the Phylocode we can have Ephemeraceae and
Pottiaceae; Isocladus and Subsecunda -- just noting that the former
is nested inside the latter. For more details and discussion see the
Phycode website and literature list at
http://www.ohiou.edu/phylocode/. Also, just for fun I attach a
summary of some of these issues that is "in press" in Taxon as part
of the Linnaean 300th anniversary symposium. [Manager's note: this arrived in
unreadable code; hopefully we can send it later.]
One comment on species: what one calls "good" species depends on the
species concept one holds. Monophyly is a good idea for taxa at that
rank too, under phylogenetic species concepts. Obviously, this is a
different (and huge) can of worms, but I couldn't let it go! :-)
cheers,
Brent
BRYONET
My own personal view of this issue is that Richard has valid
objections to any taxonomic approach that absolutely requires
monophyly. This is also, and perhaps especially, true at the species
level, since many "good" species (defined morphologically or even
biologically [reproductive isolation]) may not have had time to reach
monophyly.
The other side of Richard's coin however, is that excluding a nested
clade from the broader e.g., family or genus, is positively
misleading with regard to genealogical relationships. Treating
Ephemerum, for example, as a separate family, obscures the important
insight that Ephemerum is simply a highly modified (morphologically)
member of the Pottiaceae clade. As with paraphyletic groups in
general, this approach would mean that some members of the Pottiaceae
share a more recent ancestor with species outside the family than
they do with other Pottiaceae. Not good. An example in Sphagnum,
closer to my heart at present, is the recognition of section
Isocladus for S. macrophyllum and related species (as in McQueen &
Andrus's BFNA treatment), even though there is solid evidence (if I
dare say so myself) that these species are highly modified members of
the section Subsecunda. That approach, a section Isocladus equal in
rank to Subsecunda, totally obscures the relationship. So, when do
we try to accurately "capture" genealogical relationships, and when
do we ignore them because of phenetic distance?
Life is full of compromises ...
Now, I would expect Brent to weigh in with the view that all this
discussion argues strongly for rank-free classification.
Jon
Jonathan Shaw
Department of Biology
Duke University
Durham, NC 27708
Phone: (919) 660-7344
FAX: (919) 660-7293
shaw@duke.edu
BRYONET
There has been some discussion of Pottiaceae in the past week or two on
Bryonet. Some of the questions can be solved by studious attention to
the Code. There is, however, reference to Goffinet, Buck and Shaw's
Classification of the Bryophyta, a version on the Web
<http://www.eeb.uconn.edu/people/goffinet/Classificationmosses.html>
which extends the Buck and Goffinet original classification in Bryophyte
Biology, and Goffinet and Buck's second version in Molecular Systematics
of Bryophytes.
These classifications are the result of enormous labor by seasoned
bryologists, and are of value. They are all deeply flawed, however, in
enforcing phylogenetic monophyly on portions of the classification. I
can best speak for and defend the Pottiaceae, but I note that the two
fine families, the Ephemeraceae and the Splachnobryaceae, are lumped
into the Pottiaceae, and a somewhat less distinct family, the
Cinclidotaceae, is also lumped into it. From reading the justifications
of Goffinet and Buck in Molecular Systematics of Bryophytes, this is
solely due to requiring phylogenetic monophyly (as a taxon derived from
a common ancestor and including all descendants), such that families (or
genera) cannot derive from a clade named as a different family (or
genus). That families apparently cannot evolutionarily derive from other
families is a common justification for changes in classification, ditto
genera from genera, etc. The new classification of Pottiaceae follows
molecular studies by Werner et al., cited in MSB. On the other hand
Goffinet, Buck and Shaw did recognize Pleurochaete, well known to derive
from Tortella. They did also lump Timmiella into Pottiaceae, though it
is well-known to be phylogenetically distant from the Pottiaceae. If
there is method to their decision to require phylogenetic monophyly in
some clear-cut cases of paraphyly or polyphyly and not in others, this
is not clear.
A rigid enforcement of phylogenetic monophyly is a particularly bad
problem because it hides evolutionary information. The description of a
new family (or other supraspecific taxon) is a major event in
evolutionary taxonomy, and the rejection of the name and associated
characteristic morphological traits and sometimes biorole is wrong,
simply because of an antievolution-in-classification presumption that
taxa of higher rank cannot evolve from taxa of the same rank.=20
Relevant is the continued recognition of the family Rhabdoweisiaceae. My
paper in Bryologist (111: 292-301) demonstrated that it has no
acceptable diagnosis although it forms a reliable clade just below
Dicranaceae s.str. and other families. I believe what fuels its
recognition by cladists is that: if Rhabdoweisiaceae is actually just a
minor basal lineage of Dicranaceae with other families branching off the
Dicranaceae as sister groups distally (just as there are families
derived from distal lineages of Pottiaceae), then Dicranaceae is
paraphyletic and all genera of Pottiaceae, Eropdiaceae, Calymperaceae,
and Leucobryaceae must be transferred to Dicranaceae, and the family
names placed in its synonymy. This is even more nonsensical in the
context of reflecting evolution in classification than retaining
Rhabdoweisiaceae, which has no distinguishing evolutionary importance
other than genetic isolation, but having to choose between two bad
classifications is what adherence to phylogenetic monophyly brings.
Units of macroevolution are genera and taxa of higher rank (even though
ultimately it is genetic changes in the individual that powers natural
selection or drift), and such units should reflect as best we can
ascertain the effects of history on traits that respond to evolutionary
forces, not simply patterns in the genetic continuity or isolation
demonstrated by molecular analysis. Taxonomy informs evolutionary
thought by careful description of such units (taxa are diagnosed to
reflect apparent evolutionary differences and minimize complete
convergence). The redemption of systematics faced with difficulties in
dealing with vast numbers of species and few broad methodological
guidelines is not to follow an arbitrary classificatory system that
substitutes monophyly for evolution. It must remain evolutionary
systematics, which recognizes paraphyly as a necessary result of
reflecting perceived results of evolution in classification.
Evolutionary monophyly (one taxon derived from one other) is quite
different from phylogenetic monophyly.
I urge bryologists to reject in the Goffinet, Buck and Shaw
classification all lumping and splitting that is based solely on
enforcing phylogenetic monophyly, and is not based on reasoned
evaluation of the evolutionary importance of the taxa involved. This is
not maundering for the quondam methods of evolutionary taxonomy, but
vigorous rejection of artificial, antievolution elements in the
taxonomies of pattern cladists.
A response would be welcomed.
*****************************
Richard H. Zander
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander@mobot.org <mailto:richard.zander@mobot.org>
Web sites:
<http://www.mobot.org/plantscience/resbot/>
<http://www.mobot.org/plantscience/bfna/bfnamenu.htm>
*****************************
------------------------------------------------------------------------
Bryonet is a service of the International Association of Bryologists (IAB)
and is administered by Janice Glime <jmglime@mtu.edu>
through Michigan Technological University
IAB Officers:
President Janice Glime <jmglime@mtu.edu>
Secretary Geert Raeymaekers <geert.raeymaekers@skynet.be>
Treasurer Blanka Shaw <blanka@duke.edu>
First VP: Masanobu Higuchi, Second VP: Benito Tan
To join IAB ($11 per year), contact Blanka Shaw <blanka@duke.edu>
IAB website: http://www.bryology.org/
------------------------------------------------------------------------
--
*****************************************
Dr. Janice Glime, Professor Emerita
President of IAB; Manager of Bryonet
(Michigan Technological University)
219 Hubbell St.
Houghton, MI 49931 USA
email: jmglime@mtu.edu
phone: 906-482-1610
fax: 906-487-3167
*****************************************
From: Delphine.Aigoin@ulg.ac.be
To: bryonet-l@mtu.edu
Subject: BRYONET: Rhynchostegiella
> BRYONET
>
>
>
> \/ / D. Aigoin
> \/ PhD student in Evolution Sciences
> \ ULG / ISEM
>
>
> Dear Bryonetters,
>
> I work about the evolution of endemism in the Macaronesian bryoflora and I
> intend to reconstruct the phylogeography of Rhynchostegiella and determine
> the evolutive history of this genus. Therefore I would like to ask whether
> some of you could provide me with some samples of Mediterranean and
> African species ? (I'll be of course happy to refund the cost of the
> shipping.)
>
> Sincerely,
> Delphine Aigoin
>
>
> University of Liege (ULG)
> Department of Life Sciences
> Plant Taxonomy & Conservation Biology
> Institute of Botany, B22 Sart Tilman,
> B-4000 Liege,
> Belgium
> Tel. (32) 4 366.38.42
> ------------------------------------------------------------------------
> Bryonet is a service of the International Association of Bryologists (IAB)
> and is administered by Janice Glime <jmglime@mtu.edu>
> through Michigan Technological University
> IAB Officers:
> President Janice Glime <jmglime@mtu.edu>
> Secretary Geert Raeymaekers <geert.raeymaekers@skynet.be>
> Treasurer Blanka Shaw <blanka@duke.edu>
> First VP: Masanobu Higuchi, Second VP: Benito Tan
> To join IAB ($11 per year), contact Blanka Shaw <blanka@duke.edu>
> IAB website: http://www.bryology.org/
> ------------------------------------------------------------------------
>
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