Re: Date for Last Common Ancestor?

Stephen Barnard (
Tue, 13 Aug 1996 07:31:43 -0800

Stephen Barnard wrote:

[snipped for brevity]

> Clearly, for large N this is extremely unlikely. But it's worse than that. Even
> for small N (say N=2), for N never to reach one it would be required that both
> mothers in set S_k-1 be the *only reproducing daughter* of the two mothers in set
> S_k, and this state of affairs would have to be maintained backward in time *in
> perpetuity*!

Oops, there's a slight flaw here, but it's not fatal.

The mothers in S_k could have other reproducing daughters that weren't
in S_k-1 because their lineages died out before the present day.

Other than that, the argument still follows as before.

Steve Barnard