Climate Change On The Brain
Don't tell Al Gore: early climate change may have helped humans evolve:
Writing in the Proceedings of the National Academy of Sciences, Clayton Magill said: "The landscape early humans were inhabiting transitioned rapidly back and forth between a closed woodland and an open grassland about five to six times during a period of 200,000 years.Climate change made us smarter! Unfortunately, today's doomsayers seem to be headed in the opposite direction...
"These changes happened very abruptly, with each transition occurring over hundreds to just a few thousand years."
The findings appear to contradict previous theories which suggest evolutionary changes were gradual, and in response to either long and steady climate change or one drastic change.
Professor Katherine Freeman said: "There is a view this time in Africa was the 'Great Drying,' when the environment slowly dried out over 3 million years.
"But our data show that it was not a grand progression towards dry; the environment was highly variable."
This rapid change could have triggered development of the brain, said Magill.
He said: "Early humans went from having trees available to having only grasses available in just 10 to 100 generations, and their diets would have had to change in response.
"Changes in food availability, food type, or the way you get food can trigger evolutionary mechanisms to deal with those changes.
"The result can be increased brain size and cognition, changes in locomotion and even social changes -- how you interact with others in a group. Our data are consistent with these hypotheses.