re: First human ancestors came from Europe not Africa 7.2 million-year-old fossils indicate

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The idea that humans originated in sub-saharan africa and spread from there never made much sense to me. The sahara desert is nearly the size of the united states. No primitive people were crossing that desert to populate other lands. They would have been cooked and died.

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That's because the Sahara Desert wasn't formed until about 7,000 years ago. Humans had long left Africa before then.

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Before the great desert was born, North Africa had a moister, semiarid climate. A few lines of evidence, including ancient dune deposits found in Chad, had hinted that the arid Sahara may have existed at least 7 million years ago. But without a mechanism to explain how it emerged, few scientists thought that the desert we see today could really be that old. Instead, most scientists argue that the Sahara took shape just 2 to 3 million years ago. Terrestrial and marine evidence suggest that North Africa underwent a period of drying at that time, when the Northern Hemisphere started its most recent cycle of glaciation.

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