New techniques have shown that people reached the New World far earlier than the long-standing estimate of 13,000 years ago, but scientists still debate exactly when humans arrived on the continent—and how.
People who had cognitive functions depleted by noninvasive brain stimulation or a mentally demanding task could subconsciously recognize individual words in a made-up language more easily than controls, researchers find.
Some studies suggest that associations between the health of children and the experiences of their parents or grandparents may be due to epigenetic mechanisms, but confounding factors challenge this interpretation.
Diverse lines of evidence point to humans’ presence in the New World long before the dawn of Clovis culture. But rewriting this chapter of human history raises many questions about how these early people came to inhabit these continents.