I have to smile when I read Brent Mishler's sentence beginning, "If we
face the truth, that there is no such thing as 'species' ..."
Echoing in the back of my mind is a retort from a young creationist I
tried to engage in a discussion some years ago. In response to one of
her statements, I began, "That's an interesting belief ..." at which
point she blustered, "Well, that's not a belief, that's the truth."
End of discussion. Eventually she came to understand that a belief is
not a belief unless you sincerely think it is true. And that the
limits of truth are at the boundaries of personal belief. I believe
that Brent honestly believes that there is no such thing as species
but I do not share Brent's beliefs. I suspect this is because our
perspectives are different.
By the time I was 10 years old, I was the class "nature nut." I
collected butterflies, beetles, ferns, snakes, rocks--whatever was in
season. I wanted to know what everything was. I was kind of like
Darwin. By the time I was in graduate school my interests had narrowed
to plants and my dissertation was on ferns. That original desire to
know everything had narrowed to a stated desire to be able to walk
into the woods and be able to identify every plant I saw. Within a
local area this is not unreasonable, even identifying most on sight,
and over the past 30+ years the local area has expanded to include
most of northwestern Oregon, perhaps more.
Within this region, I can put a confident name on 99+% of the plants I
encounter. I believe the things I name have some kind of biological
reality and each a fundamental biological consistency. What are these
entities which I name? I call them species, a do all field botanists I
know. I want to know what they are and what they are doing: their
current ecological roles, interspecific interactions, genetic
composition, and, if possible, the evolutionary history that got them
here.
I am keenly aware of the dictum passed to me from Edgar Anderson by my
mentor Marion Ownbey, "Different things evolve in different ways."
Some lineages evolve rapidly, some slowly. Many, probably most,
species could be characterized by clearly defining a monophyletic
clade but many cannot. Some are simply clones (e.g., parthenogenetic
lizards, apomictic triploids) some are allopolyploids, many are still
mysteries.
I think bryology will continue to move ahead when we accept that
species are not unique, what with all their diverse historical,
cytological, ecological, genetic, biochemical, biogeographic, and
phylogenetic characters, but that they are nonetheless real in a
comprehensive evolutionary sense. This is an integrative, not
confounding, sense that keeps them in context of nature and not simply
an algorithm for analysis of an array of DNA sequences. The ongoing
problems revolve around understanding what species are, both in their
individual identity and in comparison to others, closely related or
not. And understanding why some organisms do not sort into species and
will not in our lifetimes, the fascinating 1- %. The only thing
species seem have in common is our ability to recognize them as nature
recognizes them. This is an evolutionary species concept, which I
believe in. I believe species are the basic units upon which natural
selection acts. I wish I could live long enough to bet (10:1) that in
another half century my concept of species as recognizable
evolutionary entities will persist more widely than Brent's concept of
"no such thing as 'species,'" even if a complete and perfectly
delineated phylogeny of all plants were possible to achieve.
David
----------------
David H. Wagner, Ph.D.
Northwest Botanical Institute
P.O. Box 30064
Eugene, OR 97403-1064
davidwagner@mac.com
541-344-3327
http://web.mac.com/davidwagner/Site/FernZenMosses.html
On Oct 6, 2009, at 10:36 PM, Janice M. Glime wrote:
> If we face the truth,
--
****************************************
Dr. Janice M. Glime, Prof. Emerita
Past-President of IAB, Manager of Bryonet
219 Hubbell St.
Houghton, MI 49931 USA
phone: 906-482-1610
email: jmglime@mtu.edu
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