Re: On the importance of sticks.

Robert Scott (rscott@mail.utexas.edu)
17 Mar 1995 05:31:21 GMT

In article <168966455wnr@catcrtve.demon.co.uk> Peter Mitchison,
PMitch@catcrtve.demon.co.uk writes:
>poorly, my beautiful theory was safe from inconvenient facts. I suppose
that
>you could imagine a half way house situation where the proto-hominids
(is
>there an official term for the first apes on our branch of the family
tree?)
>slept in the trees but took day-trips on to the plains to feed. I would
like
>to hear more about the evidence you mention to see whether that is a
>possibility.

Briefly, I think you're "half way house" idea might fit in with a
"woodlands" interpretation of paleoenvironments. There is carbon isotope
evidence on the grassland/woodland debate published recently (1994, I
think) in at least preliminary form in Nature (Kingston, is the name of
one of the authors I think). Also, see the work of Thure Cerling for
other carbon isotope evidence.
My undergrad. prof. mentioned a few times having fossil trees in the
Baringo Basin where he works in Africa. There has been a large amount of
paleoenvironmental work been done on Fort Ternan in Kenya (at about 14
mya a little old for hominids proper but very significant for mid and
later Miocene apes. (Fort Ternan is the site for the type specimen of
_Kenyapithecus wickerii_). (see G. Rettallack and J. Kappelman for
opposing views) Paleoenvironmental stuff for _Sivapithecus_ in Pakistan
and Turkey is also relevant. Just a few thoughts off the top of my head.
Time permitting I'll try and dig up a few more references.

I think context is the key for scenarios like thone you propose. I agree
absolutely that predation could be a large selective force. We need to
ask what was the environment like earlier, later (before? after?) what
hominids/apes were present? what trends do we see in environments? All
very fascinating stuff.

Oh, I almost forgot. Wolde-Gabriel et. al. lean towards forests (gallery
forest?) for Aramis (the A. ramidus site). (see Nature 1994 Sept. or Oct.)