Fingernails are essentially flattened versions of claws, and they evolved in all primates — including humans — to support broad fingertips, says UW-Madison anthropology professor John Hawks.
Monkeys, apes and lemurs spend a lot of time in trees, and broad fingertips help give them the strong grip needed to climb trunks and hang underneath branches.
Of course, [...]

Over the years, the mysteriously rapid way in which humans learn language has given scientists a lot to talk about.

Small doses of alcohol can kill brain cells in young lab animals. In people, they cause fetal alcohol syndrome. Anesthetics can also kill brain cells in animals. What do they do to young humans?