re: elaine morgan alternative

Mike Muller (
Fri, 05 Jul 1996 14:05:16 -0400

Mate recognition will hinder interbreeding most of the time. Also
territorality will prevent it. Just because a troop of protohumans
wandered into anothers territory won't mean they would be welcome....most
likey chased off or killed outright.

And as for overheating...the Radiator theory doesn't say that it was the
temperature on the savanna that forced bipedality. The gracile
australopithecines were pre adapted by possessing a primative network of
veins in the brain and not the O\M sinus that the robust lineages had.
This allowed for superior cooling and the ability to spend more time
explioting the newer adaptive zones that opened up with the spread of
grasses and plains. This may have just reinforced the already
semi-bipedal posture these creatures had been experimenting with. The
robusts did not have adequate cooling for their brains and there for
remained semi-arboreal and this accounts for the still-curved hand and
feet morphologies.

And finally... the Gombi chimps do not have and selective pressures on
the to become bipedal...there food supply is not dwindling, they have not
been separated from it by a growing grassland...other competitors are not
challenging them for it. All of these factors can select for a bipdeal
stance if the only available food had to be procured upright.