Re: Yersinia pestis (Minnich's research bacterium) found in ancient human bones.

On 7/11/2024 5:40 PM, JTEM wrote:

  RonO wrote:
 

A hunter gatherer diet is much better than an agricultural diet, and they might not have been very good farmers.  The advantage of agriculture is that it can sustain larger populations on the same amount of land, but those populations do not have to be very healthy.

 I have heard much the same thing for my entire life; lifespans began
to drop with the switch from hunter-gatherer to agriculture. The
advantage appears to be population densities -- a simple matter of
how many mouths you can feed.
 People didn't live even as long as Neanderthals but, evolution
works at the level of a population not an individual....
 I've often argued this point with Aquatic Ape as exploiting the sea
can support a higher population density than inland hunter gathering.
 Looking at Chimps:  The savanna supports the  _Lowest_ population
density!  So the idea that humans could have evolutionarily benefited
from a reduced gene pool seems odd, to say the least.
 

Upright walking allowed the human lineage to exploit the expanding territory opened up by the reduction of the forests.  By the time Homo erectus evolved the savanna had greatly expanded while the forests had been greatly reduced, so they had more savanna territory to exploit and their populations did not need to decline with the other apes that relied on the forests.  Homo erectus could exploit both forest and savanna, but in the forests they were in competition with the other great apes.
Ron Okimoto