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From: "David Wilson" <>
Subject: Re: [DNA-R1B1C7] The Trinity Ui Neill study
Date: Thu, 17 Jan 2008 08:24:08 -0800
References: <bd5.235eb14e.34c07cf7@aol.com><9656caf80801170703n68275d26y48c7b422a6ed5918@mail.gmail.com>
In-Reply-To: <9656caf80801170703n68275d26y48c7b422a6ed5918@mail.gmail.com>


Since we're looking only at the Y-chromosome succession here, we don't need
to worry about the ages of the mothers involved. The point is that if a
males historically fathered a surviving child every year or two between the
ages of 20 and 50, the average age for that generation is 35. I have no
doubt that tracing firstborns only would get you a new generation every 23
years or so on average, but if we are tracking all individuals who left
offspring (and specifically male offspring), the average generation would be
longer. And if we tracked only lastborn sons of lastborns, the generation
length could be quite long indeed.

This is discussed periodically on the RootsWeb DNA list, and as I recall the
statistics for people with long and complete family trees show that in the
last 300 years, the age of the father when his middle child was born was
about 30-32. I usually use 30 as a generation length -- or as a cruder
yardstick three generations per century.

David Wilson

-----Original Message-----
From:
[mailto:] On Behalf Of Paul Conroy
Sent: Thursday, January 17, 2008 7:03 AM
To:
Subject: Re: [DNA-R1B1C7] The Trinity Ui Neill study

Lochlan,

Why would you say:

I'm not sure but I think these figures are assuming a 25 year average per
generation which is probably too low.


In most of recorded history, and probably before that time too, men got
married in their early 20's and women a few years after puberty 16+, they
also lived short lives, so that figure looks conservative to me if
anything?!

Cheers,
Paul

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