On the Common Ancestors of All Living Humans
Douglas L. T. Rohde
Massachusetts Institute of Technology
November 11, 2003
Questions concerning the common ancestors of all present-day humans have received considerable attention of late in both the scientific and lay communities. Principally, this attention has focused on `Mitochondrial Eve,' defined to be the woman who lies at the confluence of our maternal ancestry lines, and who is believed to have lived 100,000-200,000 years ago. More recent attention has been given to our common paternal ancestor, `Y Chromosome Adam,' who may have lived 35,000-89,000 years ago. However, if we consider not just our all-female and all-male lines, but our ancestors along all parental lines, it turns out that everyone on earth may share a common ancestor who is remarkably recent.
This study introduces a large-scale, detailed computer model of recent human history which suggests that the common ancestor of everyone alive today very likely lived between 2,000 and 5,000 years ago. Furthermore, the model indicates that nearly everyone living a few thousand years prior to that time is either the ancestor of no one or of all living humans.