(urth) Mystery of Ascia/Agia

[Jeff Wilson]

On 1/21/2011 12:34 PM, Gerry Quinn wrote:
>
> From: "Jeff Wilson" <jwilson at io.com>
>> It is pointedly brought up within Sev's memoirs on one or two
>> occasions. It's essentialy a restatment that among a population the
>> traits most suited to their environment will come to dominate.
>
> Unless variations are very small, the idea of a 'natural country type'
> conflicts with Dollo's Law which was discussed here a while ago. Suppose
> a race evolves in Country A according to the 'natural' pattern, moves to
> Country B and after many generations adopts that country's natural type,
> and then moves back to Country A again. If they go back to the original
> type, they are violating Dollo's Law.

Dollo's Law has since been weakened to allow reversion over millions of 
years:

	http://www.pnas.org/content/91/25/12283.full.pdf

"...we show that, in fact, there is a significant probability over 
evolutionary time scales of 0.5-6 million years for successful 
reactivation of silenced genes or 'lost' developmental programs."

This is after the Book's time of authorship, so the Book doesn't have to 
agree with it, but other RL observations included in the Book don't have 
to agree with Dollo's Law as an absolute, either.


> What should happen according to Dollo's Law is that they will evolve
> traits suited to life in Country A, but those traits will not be the
> original traits. A country cannot have a single unique natural type.

This doesn't prevent a continental area from have a convergent "look" 
that newer populations can convince themselves ls essentially the same 
after 20 generations, even if it would really take more like 50.

-- 
Jeff Wilson - jwilson at io.com
Computational Intelligence Laboratory - Texas A&M Texarkana
< http://www.tamut.edu/CIL >