A game changer if it pans out.

Life on Earth is thought to have emerged from the primordial ooze some four billion years ago. Now a provocative new study argues that this miraculous transition from chemistry to biology happened not once but twice. According to the study, bacteria and archaea, the first two branches of the tree of life, each sprung separately. Life on Earth may have emerged not once but twice A game changer if it pans out.