It’s always nice to find reinforcement for what many believe are my way-out-in-leftfield theories. Some reinforcement from Mark Humphrys and others was found at http://humphrysfamilytree.com/ca.html
They use the term Most Recent Common Ancestor, abbreviated as MRCA, to refer to the search for the couple closest to present time that each and every one of us will reach if we could follow all of our own ancestral pathways far enough into the past.
There is a statement about midway through that says “when you go far enough back, every individual is either an ancestor of the whole world today, or else is an ancestor of no one alive today.” It then goes on to suggest that “far enough back” may be 700 AD, at least for the Western world.
This is the concept I was trying to describe in the Gladiator Captain’s Log http://familyforest.com/captainslog/13.html. Each and every person portrayed at the Coliseum, both in the stands and in the arena, was either an ancestor of all of us, or an ancestor of none of us.
Most of the records about most of our ancestors have been irretrievably lost forever. However, by looking at the patterns of genetic migration that can be seen by connecting the recorded history that has survived, we can gain fascinating insights into the wondrous and colorful ancient ancestry that was truly our own.