"Clades are real." Hmmm, polar bears have been shown to have evolved
from one group of brown bear. Thus:
((brown1, polar) brown2) . . . So one of the brown bear molecular
lineages and that of the polar bears make a clade.
The clade is based on the interesting fact that they share some
non-coding genetic traits that may be taken as tracking generation of
the polar bear species.
Real interesting, but are we going to base changes in classification on
this? Brown bears and polar bears are quite different even if the brown
bear occurs in two separate molecular lineages. I feel that the
circumscription of brown bear as a biological entity in nature is far
more important than basing classification on information on what group
of brown bears the polar bear came from. Clades are real, but not real
important.
R.
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Richard H. Zander
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Missouri Botanical Garden
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richard.zander@mobot.org
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and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
Non-post deliveries to:
Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, MO 63110
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