Evolution

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.

Studies of collective behavior usually focus on how crowds of organisms coordinate their actions. But what if the individuals that don’t participate have just as much to tell us?

A lizard that both lays eggs and gives birth to live young is helping scientists understand how and why these forms of reproduction evolved.

Newly discovered worlds of microbes far beneath the ocean floor, inside old basaltic rocks, could point to a greater likelihood of life elsewhere in the universe.

As COVID-19 cases continue to increase, our extensive knowledge of other coronaviruses informs our understanding.

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.

To stay healthy, humans and some other animals rely on a complex community of bacteria in their guts. But research is starting to show that those partnerships might be more the exception than the rule.

In their search for sources of genetic novelty, researchers find that some “orphan genes” with no obvious ancestors evolve out of junk DNA, contrary to old assumptions.

A recently unearthed fossil and new genomic discoveries are filling important gaps in scientists’ understanding of how primitive green algae eventually evolved into land vegetation.