|
|
Re: Exaptation and The Adaptationist Stance
Ralph L Holloway (rlh2@COLUMBIA.EDU)
Sun, 21 May 1995 23:22:12 -0400
Strange. My memory takes me back to the early 1960's when I was a
graduate student at Berkeley. I remember a particularly good student
presentation at that time by Richard Lee, who argued that
"preadaptations" didn't exist, only adaptation and natural selection. In
those days everything in early hominoid evolution were seen as
"preadaptations" for hominid evolution. Thus brachiation was viewed as
preadaptive for upright posture and bipedalism. The gripping hand was a
preadaptation for stone tool-making, and so on and so forth. Washburn's
early speculations were full of them.
Today there appears to be a major polarity between adaptationists
and selectionists that has simply gone too far. I think Smith's account
is useful and while I haven't read Dennet yet, I certainly intend to.
Exaptations might be better terms for those old 'preadaptations, but I'm
unconvinced they provide any more insight that plain and simple selection
and adaptiveness.
I was unfortunately present at S.J. Gould's James Arthur Lecture on
the Evolution of the Human Brain a couple of years ago where I learned
that language was just some epiphenomenon that grew out of brain size, a
spandrel it was, this language, this cognitive faculty of ours. More
crap. It will never explain why some microcephalics with brain sizes that
match those of gorillas are nevertheless able to engage in true language
behavior, albeit at a very reduced level of competence. I guess it is
time to reinvent another wheel invented in the '60's. Ralph Holloway.
|