erect posture and its implications

[Human <100533.1710@compuserve.com>]

Message text written by INTERNET:cadams@hh.gpz.org
>regulation<

Perhaps vertical height (and mass?) is only possible with a four chambered
heart.....a 4 C heart permits more vigorous activity and once acquired
enables size.....

I suspect that a higher metabolism is advantageous in that it permits
migration, leading to ability to continuously exploit available food
sources, leading to occupation of all available ecological niches,
squeezing out the less effiicient more reptilian fauna. How many modern
reptiles can migrate long distances...turtles, what else?

I also suspect this idea is not new.

martin