Any studies done on general likelihoods of direct-line connections?

[Robert M. Riches Jr.]

Have there been any studies done or papers published on the
topic of general likelihoods of direct-line connections as a
function of the number of centuries or generations between a
possible ancestor and a possible descendant?

I would think that at least for modern people in the US who
have anywhere near a "typical" mix of ancestors who
immigrated mostly from Europe, I would think it ought to be
possible to make a model that could predict how likely it is
that any general modern person is a descendant of any
general person who lived around 1500AD, 1000AD, 500AD, 1AD,
etc.

Thanks.

--
Robert Riches
spamt...@verizon.net
(Yes, that is one of my email addresses.)

[Bob LeChevalier]

"Robert M. Riches Jr." <spamt...@verizon.net> wrote:
>Have there been any studies done or papers published on the
>topic of general likelihoods of direct-line connections as a
>function of the number of centuries or generations between a
>possible ancestor and a possible descendant?
>
>I would think that at least for modern people in the US who
>have anywhere near a "typical" mix of ancestors who
>immigrated mostly from Europe, I would think it ought to be
>possible to make a model that could predict how likely it is
>that any general modern person is a descendant of any
>general person who lived around 1500AD, 1000AD, 500AD, 1AD,
>etc.

It isn't all that easy, since there are so many variables that have
major effects on the calculation. However this wikipedia topic
summarizes some of the results, and gives some useful links for you.

http://en.wikipedia.org/wiki/Most_recent_common_ancestor

The estimate on time estimates for most recent common ancestor of all
humans is a couple thousand years BC, but for Europeans may be as
recent as 1000 AD.

But of course this doesn't exactly answer your question. That there
may be one (unknown) person from 1000AD that is an ancestor shared by
all Europeans does not tell you the chances of being descended from
any other particular person from 1000 years ago. Still, I suspect
that the mathematics involved in that calculation might answer your
question.

lojbab

[Denis Beauregard]

On Sun, 19 Aug 2007 03:23:32 GMT, "Robert M. Riches Jr."
<spamt...@verizon.net> wrote in soc.genealogy.computing:

>Have there been any studies done or papers published on the
>topic of general likelihoods of direct-line connections as a
>function of the number of centuries or generations between a
>possible ancestor and a possible descendant?
>
>I would think that at least for modern people in the US who
>have anywhere near a "typical" mix of ancestors who
>immigrated mostly from Europe, I would think it ought to be
>possible to make a model that could predict how likely it is
>that any general modern person is a descendant of any
>general person who lived around 1500AD, 1000AD, 500AD, 1AD,
>etc.

I don't know of any study, but I can speak for Quebec early
immigrants.

The immigration during the French regime is estimated (until 1763)
roughly to :

- about 30,000 immigrants in all
- about 8,000 men married before or after migration
- about 2,000 women married before or after migration
- about half of immigrants have descendants 300 years later
(my estimate from a subset where I tried to find which immigrants
had a descendant)
- the population of today is estimated to about 5 M inside Quebec
with old French roots, and about 5 to 10 M outside Quebec, so
10 to 15 M
- one immigrant is estimated to be the ancestor of nearly every body
(95 to 99% of the population, this is based on building many
genealogical trees). This immigrant is Zacharie Cloutier and I know
one person (dead but siblings are alive) with a complete French
ancestry but not descending from Zacharie.
- on the page below, you will find statistics about the number of
married descendants before 1800 (this page is in English)
http://www.genealogie.umontreal.ca/en/lesPionniers.htm#Les%20principales%20descendances
- there were 68,000 marriages celebrated in Quebec until 1800 and the
population in 1800 should be about 150,000 to 200,000
- massive emigration outside of Quebec occured in 1850-1920, and the
not French immigration after 1759 is small so you can consider the
1800 population as all the descendants of the original 5,000
immigrants with descendants
- you can see on my site the year of marriage for all of them and
the early generations (see my sig) and I have made many genealogical
trees so you can estimate who had descendants (see this as a survey
and there are some immigrants for which I have no descendant in my
database but those descendants exist).

You can figure something from this message.

Denis

--
0 Denis Beauregard -
/\/ Les Français d'Amérique du Nord - www.francogene.com/genealogie--quebec/
|\ French in North America before 1721 - www.francogene.com/quebec--genealogy/
/ | Maintenant sur cédérom, début à 1765
oo oo Now on CD-ROM, beginnings to 1765