About 60,000 years ago, humans migrated out of Africa as the climate shifted from wet to very dry, drier even than the region is now. The researchers traced the Horn of Africa's climate 200,000 years into the past by analyzing a core of ocean sediment taken in the western end of the Gulf of Aden.

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About 60,000 years ago, humans migrated out of Africa as the climate shifted from wet to very dry, drier even than the region is now. The researchers traced the Horn of Africa's climate 200,000 years into the past by analyzing a core of ocean sediment taken in the western end of the Gulf of Aden.