Rectifying Evolution and Geneaology

[Curtis Clark]

At 03:05 PM 7/13/2002, Richard Pyle wrote:
>Goodness...I spent a LOT more time on that than I had originally intended,
>and I sort of ended up losing my direction along the way.  I guess the
>take-home message is that, although it's very convenient to represent
>evolution as a clean bifurcating tree of descent, and it's logical to think
>of evolutionary history as a "geneaology"; one shouldn't forget that the
>"true" geneaology of individual organisms works in a reticulate pattern, not
>a bifurcating one.  Actually, the "true" GENEaology isn't even about
>individual organisms, it's about individual genes (as Dawkins summarized so
>well in his classic book); and when you get to this level the reticulation
>becomes even messier (especially when you get into bacteria containing genes
>that evolved in humans, and vice-versa). On a brighter note, maybe this
>gives credibility to the idea that cladograms represent the evolution of
>characters, rather than populations of organisms -- given that "characters"
>and how they're used to construct cladograms represent the genes, rather
>than the individuals.  But I won't go there....

With all due respect, this is bogus, as bogus as the idea that quantum
physics makes chemical elements unreal, or that the circulatory system is
really just a "bunch of cells". Just because different patterns exist at
different levels of organization, it doesn't follow that some are more
"real" than others.

("Gene", btw, is the derivative word; genealogy as family tree is closer to
the Greek root.)


--
Curtis Clark                  http://www.csupomona.edu/~jcclark/
Biological Sciences Department            Voice: +1 909 869 4062
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