To explain why men are on average taller than women, scientists theorized about competition for mates. But the effects of estrogen on bone growth may be answer enough.
Why did sex evolve? Theories usually focus on the diversity of future generations, but some researchers find compelling explanations in the immediate benefits to individuals.
Only 170 million years ago, new plankton evolved. Their demand for carbon and calcium permanently transformed the seas as homes for life.
Researchers agree it’s a long shot, but transmissible cancers could theoretically evolve into independent species. Certain weird parasites might be living proof.
Researchers struggle to incorporate ongoing evolutionary discoveries into an animal classification scheme older than Darwin.
New studies revise ideas about the symbiosis that gave mitochondria to cells and about whether the last common ancestor of all eukaryotes was one cell or many.
An unexpected mechanism allows wasps to rapidly co-opt genes for new toxic functions.
A definitive explanation for why plants evolved spines remains elusive, and human biases compound the problem.