> Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and

> Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and migration. Those precise mathematical results showed that in a world obeying the simplified assumptions, the most recent common ancestor would have lived less than 1,000 years ago. He also introduced the "identical ancestors point," the most recent time -- less than 2,000 years ago in the simplified model -- when each person was an ancestor to all or ancestor to none of the people alive today This is clearly ridiculous. We have historical written records to know this isn’t true.