Researchers suggest that evolution may speed up dramatically during certain periods, challenging a long-held theory and helping explain a puzzling 30-million-year gap between genetic estimates and the ...

Oxygen played a key role in the evolution of complex organisms, according to new research published in BMC Evolutionary Biology. The study shows that the complexity of life forms increased earlier ...

Bacteria are the most diverse organisms on Earth, with a number of species that’s difficult to quantify. They’re also incredibly old. Bacteria consist of a single cell. They do not have bones and are ...