On Wednesday, August 30, 2017 at 12:10:28 PM UTC-7, wjhonson wrote: > My theory is that *every* snippet gets passed down to *someone*. OK, so let's take a medieval person who had only one child. That child receives exactly 1/2 of the parent's DNA and does not receive the other half. That means in 1 generation, 50% of the DNA gets passed to NO ONE. In every generation, even in a family with a dozen children, statistically some of those snippets will be lost completely. So much for that theory. Further, after 10 generations, the blocks that get passed are the same blocks passed for 30 generations, just in a progressively lower proportion of descendants - this means that two people claiming descent from Edward I may well share the same block of DNA, but it may be entirely coincidental if one of them descends from Edmund Crouchback, or Joan Fitz Roy, or Toda Aznarez of Pamplona, with the presence of this shared DNA being entirely coincidental and not due to the common descent you are trying to test. Even if you get a match, you haven't confirmed squat. I know you have it in your mind that it would be possible to reconstruct the genomes of medieval people simply by doing autosomal testing on the entire human population and using their pedigrees to extrapolate back, but such an approach would not survive the collision with hard reality. To argue that autosomal DNA testing can be used in this way because you think it should be possible is fantasy. taf

On Wednesday, August 30, 2017 at 1:02:17 PM UTC-7, taf wrote: > On Wednesday, August 30, 2017 at 12:10:28 PM UTC-7, wjhonson wrote: > > > My theory is that *every* snippet gets passed down to *someone*. > > OK, so let's take a medieval person who had only one child. That child receives exactly 1/2 of the parent's DNA and does not receive the other half. That means in 1 generation, 50% of the DNA gets passed to NO ONE. In every generation, even in a family with a dozen children, statistically some of those snippets will be lost completely. So much for that theory. > > Further, after 10 generations, the blocks that get passed are the same blocks passed for 30 generations, just in a progressively lower proportion of descendants - this means that two people claiming descent from Edward I may well share the same block of DNA, but it may be entirely coincidental if one of them descends from Edmund Crouchback, or Joan Fitz Roy, or Toda Aznarez of Pamplona, with the presence of this shared DNA being entirely coincidental and not due to the common descent you are trying to test. Even if you get a match, you haven't confirmed squat. > > I know you have it in your mind that it would be possible to reconstruct the genomes of medieval people simply by doing autosomal testing on the entire human population and using their pedigrees to extrapolate back, but such an approach would not survive the collision with hard reality. To argue that autosomal DNA testing can be used in this way because you think it should be possible is fantasy. > > taf However a lower proportion, multiplied by a broader base, means the same proportion or perhaps even more. And you are still stuck on two living people trying to compare their DNA to determine if they descend from Toda Aznarez. While I'm not. I'm speaking of a project which would recreate the DNA of every medieval person, by testing every living person. Not just two.

On Wednesday, August 30, 2017 at 3:12:09 PM UTC-5, wjhonson wrote: > On Wednesday, August 30, 2017 at 1:02:17 PM UTC-7, taf wrote: > > On Wednesday, August 30, 2017 at 12:10:28 PM UTC-7, wjhonson wrote: > > > > > My theory is that *every* snippet gets passed down to *someone*. > > > > OK, so let's take a medieval person who had only one child. That child receives exactly 1/2 of the parent's DNA and does not receive the other half. That means in 1 generation, 50% of the DNA gets passed to NO ONE. In every generation, even in a family with a dozen children, statistically some of those snippets will be lost completely. So much for that theory. > > > > Further, after 10 generations, the blocks that get passed are the same blocks passed for 30 generations, just in a progressively lower proportion of descendants - this means that two people claiming descent from Edward I may well share the same block of DNA, but it may be entirely coincidental if one of them descends from Edmund Crouchback, or Joan Fitz Roy, or Toda Aznarez of Pamplona, with the presence of this shared DNA being entirely coincidental and not due to the common descent you are trying to test. Even if you get a match, you haven't confirmed squat. > > > > I know you have it in your mind that it would be possible to reconstruct the genomes of medieval people simply by doing autosomal testing on the entire human population and using their pedigrees to extrapolate back, but such an approach would not survive the collision with hard reality. To argue that autosomal DNA testing can be used in this way because you think it should be possible is fantasy. > > > > taf > > > However a lower proportion, multiplied by a broader base, means the same proportion or perhaps even more. > > And you are still stuck on two living people trying to compare their DNA to determine if they descend from Toda Aznarez. While I'm not. > > I'm speaking of a project which would recreate the DNA of every medieval person, by testing every living person. Not just two. Ah, there is it. *This is not possible*. It is totally illogical and non-nonsensical. Proof: - There existed a person that every living person is descended from. For convenience sake, we shall call him "Ugg" - Posit that Ugg had 2 children, Franz and Mary. - At some point, descendants of Franz and descendants of Mary intermarried and had children, call them "the descendants". - Go Autosomal Test one of these "descendants" or any of their descendants. -> There is nothing. Absolutely nothing, that will tell you the DNA signature of Franz or Mary... or Ugg. For each segment of your DNA that came from UGG, it could have come through Franz. It could have come through Mary. You have no way to know. You also have no way to know if it came from Ugg or his wife. You can't even identify a *single* segment as being Franz's or Mary's. It isn't hard from here to construct a proof by induction that this is true for anyone alive today. --Joe C