Catching genes from chlamydiae allowed complex life to live without oxygen

Researchers has discovered a new group of Chlamydiae – named the Anoxychlamydiales – living under the ocean floor without oxygen. These have genes that allow them to survive without oxygen while making hydrogen gas. The researchers found that our single-cell ancestors ‘caught’ these hydrogen-producing genes from ancient Chlamydiae up to two-billion years ago – an event that was critical for the evolution of all complex life alive today.