How far back would you need to go in order for your family history to be meaningless?

If you found this web page and are reading it, chances are you are ardently searching for your family roots, and you find this question a bit blasphemous. However, bear with me for a few minutes.

You have two parents, four grandparents, eight great-grandparents, and 16 great-great-grandparents (2-g grandparents). In every generation removed from yourself, you double the number of grandparents in that specific generation over the previous generation.

Consider the following table which has selected entries from a complete table:

your relatives	generations from you	number in that generation
parents	1	2
grandparents	2	4
great grandparents	3	8
2-g grandparents	4	16
6-g grandparents	8	256
14-g grandparents	16	65,536
24-g grandparents	26	67,108,864

The mathematical way to calculate the number of grandparents in a particular generation removed from you is to take 2 to the exponential power of the number of generations.

The number of grandparents in generations near to you in time is relatively small. However, as the number of generations increase, the number of grandparents in each generation skyrockets.

A very important and relevant fact is that as you go back in time, the population pool of people that contain your grandparents decreases.

At some point in time, the number of grandparents in a generation will be larger than the pool of people from which they would have come.

The upshot is that at some point in time, there will a generation of grandparents that will have so many people, that your family history to that generation becomes meaningless in some sense.

Recently, I traced my family history to William the Conqueror of the time period of the Norman Invasion of England (1066 AD). Indeed, he is my 24-g grandfather and is one of the 67 million grandparents that I have in that generation. However, the entire population of all of Europe at the time of the Norman Invasion is estimated to be 38 million.

So what meaning is there on being related to William the Conqueror or anyone else who lived at that time?

For people with European ancestry, it only takes 26 generations (24-g grandparents) to have more grandparents in a generation than the pool of people living at the time. 26 generations cover approximately 800-900 years.

Every person has 67 million 24-g grandparents. For those of European heritage, there was only about half that many people, 38 million, living in all of Europe at the time those 67 million 24-g grandparents would have lived.

If as a person of European descent, you could account for all 67 million 24-g grandparents, you could be related to every living person in Europe who lived during the time period of the Norman Invasion twice over. Or perhaps, you might only be related to half the population of Europe during the time period of the Norman Invasion, four times over.

The conclusion is that there is a large number of grandparents from a few hundred to 900 years ago that would appear multiple times in every person’s family history who is of European descent.

Also, any person with a European heritage living today is probably related to most (dare say all?) other people of European descent who are now living. This is a remarkable conclusion considering we are only discussing 900 years or so of history.

Clearly, tracing your family history to a generation with more people than the pool of people living at the time takes something away from the pursuit if you desire to define yourself as having a unique ancestry. Go back 26 generations and you are no more or less unique than any stranger off the street with a European ancestry.

So, how far back can someone search their family history and find meaning?

This question can only be answered by each individual who is interested in finding their roots. However, it is an important question to answer to put your family history in an appropriate perspective. Personally, the search for my family history has enriched my appreciation with the general history of the western world.

URL: http://www.rretc.com/familyhistory/fh_meaning.html
Copyright (c) 2005 with Michael Keyes (michael.keyes@rretc.com)