This bacteria hasn't evolved in 2 billion years

1.8 billion-year-old fossil-bearing rock — (Image credit: UCLA Center for the Study of Evolution and the Origin of Life)

Fossilized sulfur bacteria off Australia's coast has provided some surprising news for scientists: The organism hasn't evolved in more than two billion years.

Researchers from UCLA collected sulfur bacteria samples that were 1.8 billion years old and compared them with samples from other bacteria in the region from 2.3 billion years ago. Both sample sets were identical to modern sulfur bacteria found off Chile's coast. The findings were published this week in the journal Proceedings of the National Academy of Sciences.

The scientists were quick to note that the bacteria's lack of evolution doesn't contradict Darwin's theory, though. The sulfur bacteria haven't evolved, but that's because their environments haven't changed, either. The fossils date to the Great Oxidation Event, Live Science notes, when oxygen levels on Earth surged. Deep sea rocks' environments haven't changed since that period, so the bacteria haven't had to change, either.