[Avodah] Your Ancestors

[Micha Berger]

R' Mike Gerver posted to Mail-Jewish in 1994 a request to help him collect
more date to tighten an argument that odds are, every Jew alive either:
- is a geir or all his ancestry are from geirim recently enough for him to
  know, or
- descends from Rashi. (Or anyone else of that era or earlier.)

See <http://www.ottmall.com/mj_ht_arch/v11/mj_v11i88.html#CYU>

Calculations involve estimating rate of marriage across social strata,
between towns, and between eidot.

All Jews. Even Teimanim. (Ethiopians weren't a discussion yet, odds are
no.)

Well, this article makes that all the more probable:
    http://bigthink.com/stephen-johnson/why-youre-probably-related-to-nefertiti-and-confucius
     Why You're Probably Related to Nefertiti, Confucius, and Socrates
     December 7, 2017   by Stephen Johnson
     ....
     [J]ust how far back do humans need to go to find a common ancestor
     of their own: a person to whom all living people are related?

     The answer, for people of European descent at least, is surprisingly
     recent: 600 years. The common ancestor for every single person alive
     on the planet today, no matter where, lived approximately 3,600 years
     ago. That means Confucius, Nefertiti, Socrates, and any figure from
     ancient history that had children, is in some way your ancestor.

Then, quoting Adam Rutherfore's new book, A Brief History of Everyone Who Ever Lived:
    "We are all special, which also means that none of us is," writes
    Rutherford in the book. "This is merely a numbers game. You have two
    parents, four grandparents, eight great-grandparents, and so on. Each
    generation back the number of ancestors you have doubles. But this
    ancestral expansion is not borne back ceaselessly into the past. If
    it were, your family tree when Charlemagne was Le Grand Fromage would
    harbor around 137,438,953,472 individuals on it -- more people than
    were alive then, now, or in total."

So, why not?

    "You can be, and in fact are, descended from the same
    individual many times over," Rutherford writes. "Your
    great-great-great-great-great-grandmother might hold that position
    in your family tree twice, or many times, as her lines of descent
    branch out from her, but collapse onto you. The further back through
    time we go, the more these lines will coalesce on fewer individuals."

    The startling discovery that all Europeans might share a common
    ancestor who walked the Earth just 600 years ago was first
    proposed in 1999 by a Yale statistician named Joseph Chang. In
    his paper Recent Common Ancestors of All Present-Day Individuals,"
    <https://www.jstor.org/stable/1428340> Chang used complex mathematical
    conceptslike Poisson distributions and Markov chainsto show how
    webbed pedigrees can overlap to produce common ancestors.

If that is true of Europeans in 600 years, Jews over 800 years lo kol
shekein?

:-)BBii!
-Micha

-- 
Micha Berger             We are great, and our foibles are great,
micha at aishdas.org        and therefore our troubles are great --
http://www.aishdas.org   but our consolations will also be great.
Fax: (270) 514-1507                        - Rabbi AY Kook