New technique pinpoints milestones in the evolution of bacteria
Bacteria have evolved all manner of adaptations to live in every habitat on Earth. But unlike plants and animals, which can be preserved as fossils, bacteria have left behind little physical evidence of their evolution, making it difficult for scientists to determine exactly when different groups of bacteria evolved. Now MIT scientists have devised a reliable way to determine when certain groups of bacteria appeared in the evolutionary record. The technique could be used to identify when significant changes occurred in the evolution of bacteria, and to reveal details about the primitive environments that drove such changes in the first place. In a paper published online Jan. 28 in the journal BMC Evolutionary Biology, the researchers report using the technique to determine that, around 450 to 350 million years ago, during the Paleozoic Era, several major groups of soil bacteria acquired a specific gene from fungi that allowed them to break down...