Climate change caused human evolution?

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Human evolution was triggered by climate change, not work, US scientists said in their recent research.They claim man had to adapt to survive the period of climate changes for over 200,000 years. Now Russian experts will study the theory.
American researchers write “the landscape early humans were inhabiting transitioned rapidly back and forth during a period of 200,000 years. These changes happened very abruptly”. This rapid change could have triggered development of the brain, social skills and tool use. Social anthropologist Alexander Kazankov finds the theory a mainstream trend of today’s anthropology. "That’s exactly how homo sapiens sapiens evolved. And that’s a fact. Abrupt climate changes trigger evolutionary mechanisms to deal with those changes." Alexei believes that the environment changes drove the evolution of the genus Homo and made people scatter across Africa, which some call the cradle of humanity, and further to other continents. However, not all scientists share the hypothesis. Paleoanthropologist Alexander Belov believes climate changes to be important but not decisive. The recent findings contradict previous theories which suggest evolutionary changes were gradual. The expert adds that it’s hard to speak about any gradual evolutionary succession or reconstruct the history of humanity. New data makes scientists change their views on evolution and no existing theory is comprehensive enough to explain all findings. The latter, on their part, aren’t linked in a single chain of evolution and some even prove that regressive evolution existed, for example brain shrinkage. Paradoxically, a Cro-magnon’s brain was 300 cubic cm larger than that of today’s human. So what anthropologists need is a new philosophical ground. "We have no sufficient evidence to be sure of anything. We lack facts- archeological, anthropological and even philosophical as Darwinism is an ideology, and it has no alternative except creationism based on religious dogmae only. So a completely new theory is needed." Some biological findings contradict cultural or climate evidence. Maybe the answer is in genomics? So we have to wait and see when the bulk of data enables scientists to tell us about our ancestors. Source: Voice of Russia