Re: Dissecting the Aquatic Ape: Bipedalism

1 Aug 1996 14:27:11 GMT

Stephen Barnard ( wrote:
: HARRY R. ERWIN wrote:

: > My understanding is that hominid evolution was quite rapid as the
: > evolution of species go. However, I was unaware that the rapidity of that
: > change was a possible argument for it being behavorially caused. My
: > understanding of chimpanzees is that they have the rudiments of a culture
: > and that the culture can change from group to group. If our distant
: > ancestors had cultures too, isn't trying to predict the behavorial basis
: > of their speciation very, very, problematic?
: >
: > If, however, we assume that hominid evolution occured as the result of some
: > learned behavior, then that event should probably be something that was
: > discovered accidentally and perpetuated through imiation and teaching. It
: > would have to become a part of the new culture. To me, the question of
: > bipedalism is a question of what changes in protohominid culture caused
: > bipedalism (and other structural changes that occured near this time) to
: > be a successful survival strategy.
: >

You got the attribution wrong.

: There is a well known idea in evolutionary theory called the Baldwin
: Effect. The basic idea is that the ability to learn can dramatically
: speed up evolution -- not only the evolution of learning, but also the
: evolution of other characteristics, including morphological
: characteristics.

See WGS Hines and DT Bishop, "On Learning and the Evolutionarily Stable
Strategy," J. Appl. Prob. 20:689-695, 1983, and H Erwin, "The Dynamics of
Peer Polities," ch. 3 in SE van der Leeuw, ed., Time, Process, and
Structured Transformation, Routledge, One World Archaeology Series, 1996
(originally presented at the Cambridge Conference on Dynamic Modelling and
Human Systems, December 10-13, 1990). Hines and Bishop show that adding
learning results in the ESS being perturbed. I show (in the context of
social dynamics) that it can even become chaotic. A speed-up, though, is
not necessarily the case.

: Perhaps the presumably "hyper" learning ability of protohumans can
: explain the very rapid evolution of hominids due to the Baldwin
: Effect.

: Steve Barnard

Harry Erwin, Internet:, Web Page:
49 year old PhD student in computational neuroscience ("how bats do it" 8)
and lecturer for CS 211 (data structures and advanced C++)