Capuchin monkeys in Brazil use big stones to crush the shells of nuts they want to eat. An experiment in the field investigated how these monkeys prepare to use new, unfamiliar tools.
Conquer the globe? You bet we did – but when did it start? A new paper shows early humans made tools in China two million years ago.
We can't observe the brain activity of extinct human species. But we can observe modern brains doing the things that our distant ancestors did, looking for clues about how ancient brains worked.