Sunday, 20 December 2009

A Question of Numbers

A spokesman for a syndicate of indigenous New Zealanders attempting to purchase large amounts of farmland in the southern part of the country was quoted in the weekend press as saying that the group had a genealogical connection, dating back to biblical times, to their Middle Eastern financiers.

He may well be right. In fact, he almost certainly is right if my arithmetic is correct. Most family trees have an average of at least three generations per 100 years. The number of any person's antecedents per generational tier doubles with each generation (e.g. you have twice as many great-great-grandparents as you have great-grandparents). Any one person has eight great-grandparents and 16 great-great-grandparents. On this basis, it's reasonable to expect that a child born in 2009 might have had two living generational tiers in 1809: 32 great-great-great-grandparents and 64 great-great-great-great-grandparents - a total of 96 ancestors living on this earth at one time, just 200 years ago. If we use the same assumptions and go back a further 400 years (12 generations) to 1400AD, a person born in 2009 might have had 390,074 direct antecedents living at that time.

If this seems incredible, go back further still. In 1009AD, the child of 2009 can reasonably claim to have had almost 1.6 billion living ancestors. The problem is, the total world population in 1000AD is estimated to have been only 275 million! The only possible answer to this anomaly is that there is a great deal of intermarriage in our ancestry and that each of us has the same people appearing repeatedly in our ancestral lines. But, all that apart, it certainly puts into perspective any claim of genealogical links going back to biblical times, which were twice as long ago!

1 comment:

  1. Having recently undertaken the task of researching my family history in Scotland my brain exploded after going back only 2 generations...or was it three. If numbers are baffling enough then gathering names was an exercise in mental torture. I lost count of the number of James Robertson's I found in those must have been very interesting at a family event ~ Fred Dagg and all his Trevor's was nothing compared to my family!!