We didn't evolve from chimpanzees, so please keep
that in mind, because we go back and forth from the
comparative record to the phylogenetic evidence from
fossils, and so forth, and we always play the game of
using the chimpanzee as our stem ancestor. Be careful
in that kind of reasoning.
[Referring to slide] These are predictions for
Homo for various structures you can get out of these
figures. Terry [Deacon] did the same thing years ago
and published it in the international journal Primatology.
As I said, what you get is 121 percent, if you
use all of the 45 primate species. If you just use Old
World and apes, it comes down to 66.6 percent but
that's still a respectable amount. If you're doing the
lateral geniculate body, which, of course, relates to
primary visual striate cortex (area 17), it's 146 percent
less than would be expected. If you're doing cerebellar
weights, 6.2 percent. Now, remember that this is log
data; confidence intervals are going in this direction,
narrowing toward the central part of the regression
line, and getting increasingly divergent at the ends of
the distribution. Consequently, 6 percent is possibly
meaningless in any significant statistical sense.