Evolution is both cultural and biological (email@example.com)
17 May 1995 16:35:28 GMT
Up to now the most plausible theory, to me, is that bipedalism was a
reactiont to the change in environamental conditions. The ability to walk
on two feet instead of bein quadruped or knuccle walker was possitive in that:
1) bipedalism is more energy efficient.
speed species energy cost
2.9km/hr Chimpanzee 0.522
2.9km/hr human 0.193
4.5km/hr chimpanzee 0.426
4.5km/hr human 0.170
2) Temperature regulation
The higher of the ground an animals body is the cooler air it comes into
The more upright posture of humans offers less surface area exposed to
the sun and heating than a quadruped.