Thaindian News

London, Nov 21 (IANS) Periods when the earth cooled or warmed have always boosted human evolution by forcing man to adapt to changing conditions and allowing migration.

Climate change not only prompted humans to migrate, but also forced them to evolve culturally by encouraging them to learn to work together.

Experts from the National History Museum and Cambridge University have identified five key time periods when shifts in global climate have resulted in accelerated social and genetic evolution.

The first began around two million years ago when a prolonged dry period caused forests to disappear leading to the emergence of Homo erectus, an early human adapted to running and hunting on the grassy plains, according to the Daily Mail.

The next major development came during the ice age which began 450,000 years ago during which scientists believe human beings were split into three separate groups. European humans evolved into Neanderthals while Asian humans evolved into Denisovans.

Those remaining on the African subcontinent evolved into modern human beings but this group had to wait until around 60,000 years ago when a prolonged warm spell allowed them to spread north.

Then, a sustained cold period between 25,000 and 15,000 years ago caused further changes as the freezing temperatures caused a 330-ft drop in sea levels allowing humans to cross the Bering land bridge into North America.

Wild fluctuations in climate between 10,000 and 14,000 years ago prompted another period of change by forcing humans to develop agricultural techniques which enabled them to stabilise food supplies.

Chris Stringer of London’s Natural History Museum and author of “The Origin of Our Species”, said: “Climate change has been a major player in our evolution.

“It created the conditions that encouraged our early ancestors to come down from the trees and later to spread out of Africa and across the globe. It made us what we are today.”

These findings will be presented at the Royal Society this week.