Protein analysis rules out multiple sources
One isn’t such a lonely number. All life on Earth shares a single common ancestor, a new statistical analysis confirms.
The idea that life-forms share a common ancestor is “a central pillar of evolutionary theory,” says Douglas Theobald, a biochemist at Brandeis University in Waltham, Mass. “But recently there has been some mumbling, especially from microbiologists, that it may not be so cut-and-dried.”
Because microorganisms of different species often swap genes, some scientists have proposed that multiple primordial life forms could have tossed their genetic material into life’s