Tim Lees

Every person alive today carries evidence of a woman who lived in Africa roughly 150,000 to 200,000 years ago. Scientists call her “Mitochondrial Eve.” She was not the first woman. She was not the only woman alive. And she was certainly not walking around as the mother of humanity. Her significance is stranger than that. Inside most of our cells are tiny structures called mitochondria, which contain their own DNA. Unlike most of our genetic material, mitochondrial DNA is inherited almost entirely from our mothers. Your mother received hers from her mother. Your grandmother received hers from hers. Follow that maternal chain backward far enough and something remarkable happens. The lines converge. Many women living alongside Mitochondrial Eve had children. Their descendants may even be among us today. But somewhere along those maternal lines, a woman had only sons, or no surviving children, and that particular mitochondrial lineage ended. Again and again, branches disappeared. One did not. Through an extraordinary sequence of mothers having daughters who had daughters, continuing across thousands upon thousands of generations, one ancient maternal lineage survived all the way to every living human population. Scientists reconstructed that history by comparing mitochondrial DNA among people alive today. And there is an important twist. There was no single prehistoric moment when one woman suddenly became humanity's universal maternal ancestor. As maternal lineages disappear, the identity of our most recent common maternal ancestor effectively moves forward through history. “Mitochondrial Eve” is therefore not a biblical Eve. She was a real woman within a much larger population whose mitochondrial lineage happened to survive when others eventually vanished. We don't know her name. We don't know what she looked like. She lived and died without knowing that anything about her was unusual. Yet an unbroken biological thread connects her to roughly eight billion people alive today. #archaeohistories