Evidence Suggests Climatic Changes Spurred Evolution

Off the coast of Africa, a Columbia University expert has discovered the first detailed evidence of ancient climatic changes that may have spurred human evolution.

No one knows for certain what forced humanity's remote ape-like ancestors to forsake the trees they called home, why some prehuman species surpassed others, or why primitive human ancestors migrated out of their African homeland. There are, experts say, as many theories as there are fossils.

But new research suggests that weather may be at the root of the human family tree.

An analysis of ocean sediments made public earlier in October shows that in the past 3 million years the cradle of …