[Avodah] Mitochondrial DNA and the Mabul

[Zev Sero]

On 21/09/2012 4:00 PM, Micha Berger wrote:
> BUT... this doesn't really help align the Torah with scientific
> observation for a totally different reason. More cosmic rays and mutations
> also means more cancer. Rather than longer lifespans than today, we
> should expect far shorter ones. Despite any differences in nutrition.

We don't know what the *average* lifespan was.  More mutations ought
to mean a lot of unsuccessful mutations that cause miscarriage or a
short life, but also a lot of successful mutations that lead, in the
presence of better nutrition and climate, to a longer life.

But if that doesn't seem plausible to you, consider my suggestion that
the cosmic ray bombardment occurred during the mabul itself, when the
van allen belts were probably completely inoperative (along the lines
of "hotzi chama minarteka").

However we look at it, though, the 8 individuals who survived the mabul
only had 16 versions of each chromosome between them, so even if each set
was as different as 1500 years of rapid mutation could make them (while
maintaining interfertility) the genetic diversity of their children is
still limited.  What we really need is a high mutation rate in the
centuries *after* the mabul; this might be explained by the van allen
belts taking time to reform (or to form in the first place) after a
polar realignment.

-- 
Zev Sero        "Natural resources are not finite in any meaningful
zev at sero.name    economic sense, mind-boggling though this assertion
                  may be. The stocks of them are not fixed but rather
		 are expanding through human ingenuity."
		                            - Julian Simon