2016-12-27 01:13:04 UTC
it should have got away independently more or less simultaneously in
several independent parts of the world. Susan Corwin argues that
agriculture got under way only when it became possible and backs up
her thesis with paleo data.
Prior to about 13,000 years ago the climate of the earth was extremely
dusty (think 'dust bowl') indicating that conditions were extremely
unfavourable for plant growth.
" Living in a Dust Storm: the Genetic and Behavioral Bottleneck:
For over 60,000 years, about 3000 generations, far longer than the
time back to the stone age, the struggle to survive was huge.
=> likely, all species of land occupants were endangered:
plants, animals, insects, etc."
The primary reason that conditions were so poor was that atmospheric
CO2 was at a level where plants had great difficulty growing.
Agriculture only got underway when atmospheric CO2 rose above 230ppm.
[This probably occurred as temperatures began to rise at the end of
the ice age. EES]
For more information see http://tinyurl.com/j5sxp5l or