The evolution of plants and animals generally has been thought to occur through the passing of genes from parent to offspring and genetic modifications that happen along the way.

A team headed by scientists from the Institute for Research in Biomedicine (IRB Barcelona) reports how the protein Ler, which is found in pathogenic bacteria, interacts with certain DNA sequences, thereby activating numerous genes responsible for virulence, which bacteria then exploit to infect human cells.

Maintaining fluid balance in the body is essential to survival, from the tiniest protozoa to the mightiest of mammals.

A new study of more than three dozen bacteria species — including the microbes responsible for pneumonia, meningitis, stomach ulcers and plague — settles a longstanding debate about why bacteria are more likely to steal some genes than others.

Since the days of Darwin, the "tree of life" has been the preeminent metaphor for the process of evolution, reflecting the gradual branching and changing of individual species.