DNA

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.

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.

Studies suggest that epigenetics allows some learned adaptive responses to be passed down to new generations. The question is how.

Origin-of-life researchers have usually studied the potential of pure starting materials, but messy mixtures of chemicals may kick-start life more effectively.

Modern humans and more ancient hominins interbred many times throughout Eurasia and Africa, and the genetic flow went both ways.

To avoid passing on new mutations to offspring, plants may minimize the number of divisions by the stem cells that make flowers and seeds.

The discovery that apparently dead cells can sometimes resurrect themselves has researchers exploring how far they can push the point of no return.

Surviving fragments of genetic material preserved in sediments allow scientists to see the full diversity of past life — even microbes.

New work raises the estimated diversity of viruses in the seas more than twelvefold and lays the groundwork for a better understanding of their impact on global nutrient cycles.