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Ancestry

PostPosted: Tue Feb 15, 2022 12:00 am
by netzerkaiser
Looking into the issue of ancestry, I found that by 2 to power of whatever, you'd have an impossible for the time, bunch of ancestors. To quote Wikipedia on 'pedigree collapse"...

Without pedigree collapse, a person's ancestor tree is a binary tree, formed by the person, the parents (2), the grandparents (4), great-grandparents (8), and so on. However, the number of individuals in such a tree grows exponentially and will eventually become impossibly high. For example, a single individual alive today would, over 30 generations going back to the High Middle Ages, have 230 or roughly a billion ancestors, more than the total world population at the time.[2][pages needed]

This paradox is explained by shared ancestors, referred to as pedigree collapse. Instead of consisting of all different individuals, a tree may have multiple places occupied by a single individual. This typically happens when the parents of an ancestor are related to each other (sometimes unbeknownst to themselves).[3][4] For example, the offspring of two first cousins has at most only six great-grandparents instead of the usual eight. This reduction in the number of ancestors is pedigree collapse. It collapses the ancestor tree into a directed acyclic graph.


I find it fascinating, that you could have same great great great great great great great great great great great great great great great grandfather present maybe three times. It just opens out to me how related we all are.

Re: Ancestry

PostPosted: Thu Feb 17, 2022 12:25 am
by netzerkaiser
Vagabundo1 wrote:
netzerkaiser wrote:Looking into the issue of ancestry, I found that by 2 to power of whatever, you'd have an impossible for the time, bunch of ancestors. To quote Wikipedia on 'pedigree collapse"...

Without pedigree collapse, a person's ancestor tree is a binary tree, formed by the person, the parents (2), the grandparents (4), great-grandparents (8), and so on. However, the number of individuals in such a tree grows exponentially and will eventually become impossibly high. For example, a single individual alive today would, over 30 generations going back to the High Middle Ages, have 230 or roughly a billion ancestors, more than the total world population at the time.[2][pages needed]

This paradox is explained by shared ancestors, referred to as pedigree collapse. Instead of consisting of all different individuals, a tree may have multiple places occupied by a single individual. This typically happens when the parents of an ancestor are related to each other (sometimes unbeknownst to themselves).[3][4] For example, the offspring of two first cousins has at most only six great-grandparents instead of the usual eight. This reduction in the number of ancestors is pedigree collapse. It collapses the ancestor tree into a directed acyclic graph.


I find it fascinating, that you could have same great great great great great great great great great great great great great great great grandfather present maybe three times. It just opens out to me how related we all are.



Once humans developed agriculture and became sedentary, I think many populations didn't travel very far, no more than two weeks journey, in search of a mate. This would indicate that those at the very high end of the social ladder (princes, queens) may be least inbred portion of society. They had long tradition of marrying people from other nations and kingdoms. Far farther than commoner. Yes they married cousins from time to time, but distant ethnic marriage probably more than compensated.


Yeah, I hear you. Just so fucked up to me. I think I never understood that 10 generations ago there were over 1000 people equally carrying your DNA - lofty & low by societal norms. And then you've likes of Churchill, descendent of Marlborough, but Marlboroughs DNA input, to Winston himself would be minimal, maybe 1/700th of his DNA... but to read history books you'd think he was his grand-dad.

Re: Ancestry

PostPosted: Thu Feb 17, 2022 10:12 am
by Iddaoeeok
Vagabundo1 wrote:Once humans developed agriculture and became sedentary, I think many populations didn't travel very far, no more than two weeks journey, in search of a mate. This would indicate that those at the very high end of the social ladder (princes, queens) may be least inbred portion of society. They had long tradition of marrying people from other nations and kingdoms. Far farther than commoner. Yes they married cousins from time to time, but distant ethnic marriage probably more than compensated.


Actually not true, royalty and aristocracy tend to be more inbred through the need to marry people of the same status. So you end up with the Habsburg jaw; the 'chinless wonder' stereotype of the British aristocracy; Queen Victoria's legendary fecundity leading to haemophilia being rampant among the royal families of Europe and King George V and Tsar Nicholas II looking like twins.

Re: Ancestry

PostPosted: Thu Feb 17, 2022 11:52 pm
by netzerkaiser
Iddaoeeok wrote:
Vagabundo1 wrote:Once humans developed agriculture and became sedentary, I think many populations didn't travel very far, no more than two weeks journey, in search of a mate. This would indicate that those at the very high end of the social ladder (princes, queens) may be least inbred portion of society. They had long tradition of marrying people from other nations and kingdoms. Far farther than commoner. Yes they married cousins from time to time, but distant ethnic marriage probably more than compensated.


Actually not true, royalty and aristocracy tend to be more inbred through the need to marry people of the same status. So you end up with the Habsburg jaw; the 'chinless wonder' stereotype of the British aristocracy; Queen Victoria's legendary fecundity leading to haemophilia being rampant among the royal families of Europe and King George V and Tsar Nicholas II looking like twins.


I'd tend to go with you on that, Idaoeeok - its a great point, though the other chaps point in my opinion does have equal merit, & he made it with equal eluquence. Its like two faces of the same coin, to me. Idaoeeok, I think my reference of Marlborough comes from the beautiful (to me) scene below, which imagines the meeting of 'mad Jack' Sassoon & Wilfred Owen in WW1 'rehab' centre. I'd love you to see it. I think its touching on so many levels.

https://www.youtube.com/watch?v=FuzRR3jVgS0

Actually today at work I found time to research the war of the Spanish succession (1701–1714) where John Churchill (Marlborough) made his name with his victories at Blenheim (1704), Ramillies (1706), Oudenarde (1708), and Malplaquet (1709) & was shocked at the casualties of this war, perhaps 500,000 odd on the both the French & British parties sides. I was aware of the 7 years war, largely through Kubricks Barry Lyndon https://www.youtube.com/watch?v=rh6C4Zpvngc & the Great Northern war between Sweden & Russia, both in that century, the former over a half-century later in fairness.

Anyway the point of my thread is that I' was so blinkered in my own way, that I never understood until a few days ago, just how many people contributed to your existence. Somehow I imagined you had 2 sets of grandparents going back to 2 sets of great great great great great great great grandparents etc, not withstanding this 'pedigree collapse' element, but I can't be the only one.

If you get a chance try the Melville Samourai movie I uploaded link for. I'm just going to watch it again right now, 2nd half, I watched 1st half last night. I think its a moving experience. The composer of the soundtrack, who died tragically young in a diving accident, to me, seems to anticipate 'Tubular bells' years in advance.

Hope you're keeping well too.

Re: Ancestry

PostPosted: Fri Feb 18, 2022 1:42 am
by netzerkaiser
I think we're all coming in at different angles. But look, discussion is good, respect is paramount.

Re: Ancestry

PostPosted: Sat Feb 19, 2022 4:11 pm
by Iddaoeeok
Vagabundo1 wrote:Take a look at list of ancestors for some lineages in European royalty, known ancestors were even from nations outside Europe. Not so many English would be having ancestry outside of Europe from that time. Account also English Royal family has German and French ancestry along with others.


This is true but, at a certain point, European royalty were increasingly drawn from the same small and diminshing gene pool and they, more or less, were all related to one another. This is why a fairly obscure minor German royal house could legitimately claim the throne of the United Kingdom. Nationalities are actually meaningless when it comes to European monarchies. I mean Prince Philip was born in Greece to Prince and Princess Andrew of Greece and Denmark but there was not a drop of Greek blood in his body, his lineage was basically from same few German royal houses as his future wife. Philip's mother was Queen Victoria's great-granddaughter and Elizabeth's father was Queen Victoria's great-grandson.