Re: Bidpedalism

6 Jun 1995 16:00:45 GMT

Ralph L Holloway ( wrote:
: Harry sure does remind me of my graduate days at berkeley in the '60's.

UCD, 1964-68, BS Math
UCSD, 1968-1972, MA Math with written quals completed for a PhD in
algebraic topology.
In the interim, research in non-linear dynamics and behavioral biology.
GMU, 1994-95, halfway done on a PhD in computational science and
informatics (computer-oriented operations research and scientific
--Hence not a bad guess, and yes, I'm regressing. It's my last chance to
have some fun before I have to eat my brain and settle down.

: Gorillas coming down to the ground to escape predators. Just how many
: instances have you seen of this action? How much do gorillas weigh? Why
: would they be so stupid as to brachiate away in fear through the trees
: when they can place their 600 pounds on the ground and intimidate just
: about any other animal besides ourselves. As for Oxnard, whom I deeply
: respect, his analysis is probably based on some multiple discriminant or
: componet analysis, which isn't really evidence but is a technique (or
: set of them ) used to shore up an hypothesis or an interpretation.

Yes, he likes to blow the reader away with statistics. At least he's more
qualified to do that than A. Q. Morton. This is more solid than his
typical results.

: SAgain, the question is Harry's attribution of a set of terrestrial
: adaptations more evolved than in Australos (graciles too) and Homo
: habilis. Knuckle walking is surely one adaptation to a terrestrial
: habitat, but so is bipedalism, and it stretches the meaning of either of
: these different adaptations to call one more terrestrial than the other.

Especially as the A. lived in a different environment than the African
great apes. I agree.

: There is no evidence to get the Nariokotome youth derived from KNM-ER
: 1470. Maybe from H. ergaster, but those are rather contemporaneous with
: 15000.

I'm suspicious early Homo had had a patchy distribution with many local
populations and a lot of variation. My database has that look about it.
The population characterized by KNM-ER 15000 was possibly the first that
managed to break out of the ecological constraints on the earlier niche.

: And for OH62, it would be neat if we had some decent cranial
: evidence with it. Limb proportions from fragmented postcranials are not
: the soundest evidence, given that we lack any real knowledge of such
: variation 1.8 million years ago.


: An can all of the stress analyses done
: only come up with climbing as the what is being adapted to? Would
: dragging carcasses around provide the same stress patterns?

Probably not, since there would not be the same sort of fitness gain
associated with being able to lug a carcass just a bit bigger. We're
looking for a fitness function that leads to an optimally curved set of
fingers, where tool-using and load-carrying seems to result in straighter
fingers. (Of course, that could be a consequences of premature convergence
in a small population with accidently straight fingers, but that could be
tested using data from H. erectus and H. sapiens populations.) Anyone for
a project?

: What else
: was around to make those footprints at Laetoli?

What's this about a rumored find of an early robust (circa 5 MY)? BTW, has
anyone ever studied that extinct lemur illustrated in Szalay and Delson
that appears similar to the robusts in cranial morphology. It might
provide some insight into hominid adaptations

: Sasquatch? Finally, all
: of observations of chimps and gorillas are on animals living in (now)
: protected enclaves, and it is likely that their distribution over the
: past few millions of years has been far more extensive and within an
: arborial ecological niche far less broken than now (IMHO).

That article on possible evidence for extended isolation of Pan t. verus
is of some interest here.

: Nevertheless,
: that we debate these points is excellent, and shows just how weak the
: fossil evidence, as well as much of our functional analyses. Lets keep
: it up.
: Ralp Holloway.

Cheers --
Harry Erwin
PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"