Re: Neoteny was Re: god makes hubey

H. M. Hubey (hubey@pegasus.montclair.edu)
25 Nov 1995 17:48:13 -0500

n8010095@cc.wwu.edu (Phillip Bigelow) writes:

>hubey@pegasus.montclair.edu (H. M. Hubey) writes:

>>>To me it's strange. IF I extrapolate from say lizards, to dogs, to cats,
>>>to chimps, to humans, I wind up thinking that future of humans is
>>>like what the sci-fi writers imagine; smaller jaws, larger eyes,
>>>larger braincases, less body hair, etc... Well, that looks a
>>> lot like a human baby.

> You can't extrapolate from lizards to dogs to cats, Mark. The phylogeny
>doesn't follow that tree at all.

OK, reptiles..

Just imagine that you've been given a million dollars and have working
for you the people who make those morphing movies. Take the bones of
the various kinds of animals that I wrote above, and create 3D images
of them on a computer. Then run the morphing program so that it fills
in the gaps between them so that there's a smooth transition from
one to the other.

And then run the program and watch the screen as the skull shape
goes from reptile to human. Just imagine it. If you want a little
help with your imagination check D'arcy Thompson's book.

>1) Although cats display more apomorphies than do canids, they did not evolve
>from canids. Therefore, there is no linear relationship for those two
>animals.

Dead end from another branch. It's too bad you keep forgetting what
these trees are and what they mean and why this whole idea of a
tree is used in the first place.

>2) Lizards are a relatively well-derived (read "highly-evolved") group of
>reptiles. Further, they are not the ancestors of dogs or cats. So there is
>no linearity in this case either.

There's no linearity anyway, whatever it means in this case. I should
have said reptiles.

>3) Chimps and humans evolved from insectivorous mammals, NOT from
>carnivorous mammals such as dogs or cats. So, there is no linearity in
>this case either.

Another dead end. But there's a continuous linkage, the trunk of the
tree so to speak. The others are the more highly evolved and hence more
fit versions of the splits from the main trunk, and share a lot
with the ancestors from which they split.

The same idea, a slight change.

-- 





				Regards, Mark

				http://www.smns.montclair.edu/~hubey