Talk:Pedigree collapse

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[edit] Alfonso XIII

Rmhermen asked me the source for my change of Alf's gggparent's count from eight to ten. I first noticed that the Snopes article linked to from the Pedigree collapse page said ten, not eight, gggparents. I then found this page: [1] which showed a full pedigree. It shows his father had 4 ggparents and his mother had 6 ggparents. (Of course, his father, Alfonso XII, had no more than 8 gggparents by this reckoning.) -R. S. Shaw 22:01, 2004 Nov 29 (UTC)

Regarding "Some geneticists believe that everybody on earth is at least 50th cousin to everybody else."

I User:jamesdowallen challenge this assertion. Most pairs of people are much closer than this; some pairs are much further! First, note that cousins grow (in simplistic model) by a factor of 4 per generation (not factor of 2 as for ancestors), so one would have 4 billion 15th cousins!" This ignores pedigree collapse, but a good guess would be that any two Europeans are closer than 20th cousins. As for "everybody on earth", what about the relation between, say, an Australian aborigine and an Amerindian deep in Amazon jungle? Is there any reason to suppose all such people have post-Columbian Eurasian ancestors? Is there any guarantee of trans-Pacific contact after early migrations? "50th cousin" implies the two isolated aborigines would have a common ancestor within the last 2000 years (approx). Is there any reason to believe this?

Please read up on this at Most recent common ancestor and its linked pages. Rmhermen 13:22, 11 January 2006 (UTC)

Also, that's why the sentence says some geneticists believe ... It's not presented as a hard fact, it's an expression of a hypothesis/theory held by a reasonable number of people in the field. If it said Everybody on earth is at least 50th cousin to everybody else then your challenge would be very appropriate. - DavidWBrooks 14:20, 11 January 2006 (UTC)