The citizen-science app iNaturalist lets you record observations of plants and animals. The data can be used to study biodiversity.

Heliconian butterflies choose mates with similar wing patterns. Their genes make them do it.

Scientists explore the causes--climate change, habitat destruction, and more--that decimated animals and humans alike, from Ice Age to Internet Age.

Scientists have found there are actually four different species of giraffes. But what makes a species?