Researchers’ simulations suggest that small population sizes and inbreeding made Neanderthal populations vulnerable to chance fluctuations in population size.

The big cats show signs of inbreeding despite conservation efforts to diversify their populations.

Populations of the two-foot-long amphibians are declining across North America. Scientists are struggling to find out why, before it’s too late.

In the last year, the butterfly’s eastern group has more than doubled its hibernation area while the other population waned. Plus, researchers are moving trees to save monarch habitat.

Researchers plan to relocate mainland wolves to an island in Lake Superior in an effort to boost the near-extinct predator population and limit the growth of local moose herds.

The variation may help explain why stocked salmon don’t fare as well in the ocean.

A 27-year-long study finds insect biomass has declined by about 75 percent. 

Researchers trace the mixing of human populations using DNA.

Joel Cohen uses the tools of mathematics to deconstruct questions of life.