The animal kingdom stretches anatomy far beyond human expectations. Some creatures carry organs that rival furniture in size, ...

More than 1.5 billion years ago, a momentous thing happened: Two small, primitive cells became one. Perhaps more than any event—barring the origin of life itself—this merger radically changed the ...

This article was originally featured on Knowable Magazine. More than 1.5 billion years ago, a momentous thing happened: Two small, primitive cells became one. Perhaps more than any event—barring the ...