Whenever I look at the chart below I think about the one-sidedness of genealogical studies and the justification of “blue blood.” This simple chart show tear to shreds any justification that we haven’t mixed with other ethnic groups if we all once migrated from Africa.
The question isn’t how different we are but how closely related we are.
Category: Enrique Tessieri
Without commenting the issue of mixing with different ethnic groups, I would like to remind you that the way you are calculating is seriously wrong. 2^199 is 803469022129495137770981046170581301261101496891396417650688 which is many many orders of magnitude larger than even the estimates of the number of people ever lived. What you are missing is inbreeding, with more or less closely related persons. Especially in the past, inbreeding has happened typically with quite closely related persons as villages were small and travelling large distances difficult.
If we want to know more about this kind of things, we should turn into genetics, instead of flawed napkin calculations. For example, it seems that non-African populations might have 1-4 % of genome which has come from the Neanderthals genome through interbreeding.
It’s not just inbreeding that leads to pedigree collapse. Pedigree collapse also happens when we descend from more than one offspring of two parents, which is quite common. This brings the total number of descendants down considerably, because the otherwise second set of parents is eliminated in that generation – and all following generations. As an example: William Marshall is my 23rd.-25th. great-grandfather through all five of his daughters. Maude, Eva, Isabel, Sybil, and Joanne.
PsVoter i want you to read this [story about a] scientific article about neanderthal and homosapiens interbreedinf if ever occured.
I thought it might be useful to put your story quote into blockquotes, D4R. Let me know if there is something that you want changed. Good reference, by the way.
Thank you Mark. Can you be a bit specific what you mean by my story?
Oh i got it Mark what your saying. I dont mind it and thank you for putting my posted article in to blockquotes. It’s fine like that, nothing need to be changed. Thank you.
Great to read your comments, D4R!
Thank you Enrique.
My great grandparents, of which we all have 8, were first cousins, which means that I have 14 instead of the 16 great-great grandparents dictated by pure arithmetic. There are several of these cousin marriages in different branches of my tree, which means doubling each past generation is wrong, and I’m quite confident that most people, if they look back far enough or carefully enough, will find the same in their trees. The chart is wrong by at least this factor.
Hi Gene, thank you for your comment. If you calculate the matter your way, how many grandparents would you have if you went back 200 generations?
A person’s 200th generation is made up of the 196th generation of each of their 8 great-grandparents. Since two of my g-grandparents have the same ancestry, it’s the same as removing one of those 196-generation trees. Theoretically, that means my 200-generation tree would have 12.5% fewer ancestors from their generation back. However, some of the 7 remaining g-grandparent trees also have at least one and in some cases more cousin marriages. The total deduction from my 200-generation tree would depend on the number of those marriages and how far back in the tree they are. In short, I have no idea the actual number. I doubt it’s possible to know, but the number is significant. I think it’s unlikely to the point of impossibility that anyone has ever had the theoretical number of ancestors the chart indicates.