Re: Where are the zoologists?

Bryce Harrington (bharring@girtab.usc.edu)
8 Jan 1995 18:18:52 -0800

In article <3d7t85$bre@badger.3do.com> jjh@3do.com writes:
>>>In article <3cipq6$8a6@badger.3do.com>, jjh@3do.com (Joel Hanes) writes:
> bharring@phakt.usc.edu (Bryce Harrington) writes:
>>
>>I could believe this if the feature was sometimes present, sometimes
>>not, for example blue eyes, inny-belly buttons, left-handedness, etc.
>>But for features which are dominant and universal throughout the
>>entire species, like the nose, hairlessness, adiapose fat, bipedalism,
>>etc. there needs to be an explanation.
>
>No. Some things just happen from historical contingency.
>
>To the best of my knowledge, all humans have a vermiform appendix.
>To the best of my knowledge, this trait is a historical accident,
>not an adaptive response to selection pressure.

Eqven if the appendix is _not_ useful today, it was at one time useful
for something. I did _not_ say that things that are present must be
adaptions; I said that they must have an explanation. The appendix
needs to have an explanation, even if it is a so-called "historical
accident." That is my point: the traits in question need an
explanation.

It may very well be that fat, hairlessness, et al are also historical
accidents, but that does not excuse them from needing investigation,
as an earlier poster claimed. The reason could be derived from AAH,
or from some other hypothesis, but the traits should not be swept
under the rug. In the case of the traits in question, they may very
well provide the answers (or at least leading questions) to the
solutions we seek.

>The organs in the human abdomen are supported by stringy tissues
>depending from the backbone. This arrangement is decidedly
>bad for an upright biped, but good for a quadruped.
>Do you claim that this trait that we all share is adaptive?
>I claim it's a historical accident.

Fine, those are obvious leftovers and solid indications that we were
once quadropedal (of course, since these traits are soft tissue they
don't count as evidence ;-)

Anyway, you missed my point. Even if they are not adaptations, they
need to be explained and not ignored as some people argue.