All Modern Life Derived From One
From Discovery News. All Modern Life on Earth Derived from Common Ancestor A single, primordial event likely yielded the array of organisms living today. Fri May 14, 2010 05:15 PM ET Content provided by Tina Hesman Saey, Science News 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 mix, creating a web, rather than a tree of life. To determine which hypothesis is more likely correct, Theobald put various evolutionary a...