Adam Primal parent of our race Taken from Mapping Human History by Steven Olson
Counting Our Ancestors • One generation ago each of us has 2 ancestors • Two generations ago each of us has 4 ancestors • In each subsequent generation the number of ancestors double. • Three generation 8 ancestors and 4 generations we have 16 and so on • Or 2n = the number of ancestors • where n = the number of generations
Counting Our Ancestors • If each generation = 20 years • Then 30 generation ago would equal about 600 years ago • At 30 generations each of us would have more than a billion ancestors. (230) • A billion people did not live on earth in the year 1400. (The actual estimate is around 375 million)
Circles of inheritance • At some point lines of inheritance cross so that one person will contribute more then once to your ancestry. (Circle of inheritance) • Example cousins that marry. Their children would only have 6 great grand parents instead of 8. • The greater the number of generations taken into account, the greater the possibility that any two people who marry are distant cousins. • By the tenth generation virtually all of us have circles of inheritance
Critical Threshold • Even after taking into account circular inheritance, the number of ancestors become critically large after about 40 generations or 800 years ago. • At this point Europe and Africa each had about 50 million each. Asia had no more then 250 million • Our ancestors 800 years ago probably included much of the adult population in those regions of the world where they lived
Joseph Chang, a statistician from Yale University, showed that • all of the people living in various regions of the world more than 800 years ago can be divided in to two categories. • Each individual was either the direct ancestor of everyone in that part of the world alive today • Or the person’s linage went extinct.
Migrations • Example Aisa • 800 years ago one of your millions of ancestors was a European adventure who settled in a town on the silk road and married an Asian women. • The children of the pair married other Asians • That European today would be an ancestor of the entire population of Asia.
Implications • The exponential growth in the number of our ancestors going back in time connects us to the people of the past • If a historical figure who lived more than 1600 years ago had children who themselves had children, that person is almost certainly among our ancestors. • Everyone in the world today is most likely descended from Nefertiti, Confucius and from Julius Caesar
Biblical Implications • Because of the exponential growth in the number of our ancestors through time, everyone of us alive today is extremely likely to have descendent from Adam and Eve who lived over 6000 years ago. • However, If there were others living at this time, or before this time, we must have descended from them as well.
Other Biblical Implications • Which of the twelve tribes of Israel are you descended from?