African "megadroughts" likely played a role in where and when early humans traveled.
Two research teams have reprogrammed adult cells into stem cells—without using embryos.
Under human influence, species are spreading faster than ever.
Stem cells are revolutionizing disease study and treatment.
A new study shows that primates' precision grip evolved more than once.
Vietnam's threatened, still-mysterious biodiversity gets a conservation connection.
Clues to endurance running and other unique human traits.
The delta's levees are no match for a big earthquake.
A feast before its time.
A predator returns - and reverses decades of aspen decline.