Due to climate change, the prospect of nuclear war, and a political disregard for facts, the doomsday clock is now closer to midnight than any time since the 1950s.
The newly sequenced genome of an Alaskan infant who lived just after the last Ice Age provides clues about the ancestry and migrations of early Native Americans.
Nomads migrating into Europe during the Stone Age may have brought the plague, setting the stage for epidemics like the Black Death, which killed at least 25 million people.
