Maybe they are just in stage 1? Stage 2 is to outbreed and get hybrid vigor.

Come to think of it, maybe that's what we see in the Muslim world, with occasional mixing of inbred lines?

Or like linebreeding in thoroughbred race horses. ;)

Come to think of it, maybe that's what we see in the Muslim world, with occasional mixing of inbred lines?

i don't think it scales that far. that's why the mormon fundamentalist case is interesting, it can plausibly be a 'super-organism' because of its small size.

Razib, I think you missed my intent with respect to Muslims. I meant that the pattern of cousin-marriage creates problems due to inbreeding, but when cross-breeding of inbred lines does occur (and it's not that uncommon) you get the reverse: the benefits of hybridization.

It is interesting to note that the Saudi royal family has a tradition of out-marrying to create alliances with all major tribes. The Saudi royals do seem to me more "vigorous" than average.

They should just hire a consulting geneticist to help in the match making ;)
With a eugenic direction, they could actually get benefits from their inbreeding, develop a skill set that exploits a profitable economic niche, concentrate all the intelligence and vigour into an upper class, and give that class more wives, etc. And if/when faced with dying out, which seems unlikely given their above average reproductive output, they could THEN resort to some degree of outbreeding. The pro-natality of their society makes them effectively MORE healthy and secure in future than the average westerner living in a society with a below replacement birthrate, these polygamists should laugh at any westerner saying THEY are taking a poor biological strategy.

It is interesting to note that the Saudi royal family has a tradition of out-marrying to create alliances with all major tribes. The Saudi royals do seem to me more "vigorous" than average.


my understanding is that in the heirarchy of princes the most "inbred" are the high status. ergo, these would be the ones to reproduce to the greatest extent in generation two.

but when cross-breeding of inbred lines does occur (and it's not that uncommon) you get the reverse: the benefits of hybridization.

the benefits of hybridization will be a bounce back to population normality, these traditions of inbreeding in places like saudi arabia aren't really selecting for new traits. in other words, it isn't like you have two groups of saudis each being selection biased for a high frequency of a given advantageous trait, and then subsequently hybridized to nick & exhibit both traits without the drag of unmasked recessives.

Hello all,

I just made the jump to Razib's blog from somebody else's -I forget and I'll research it later since spontaneous leaps of all kinds interest me, but first: has anyone here read and would comment on Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life, by Eva Jablonka and Marion J. Lamb?

There's a review over at TNR.com that, now that I think about it, may have had something to do with my arrival here, but anyway, I'm curious to know more. Here's the quote that pricked my imagination:

"Until recently, it has been assumed that mutations are non-adaptive and not developmentally controlled, but such examples suggest otherwise. If the apparatus responsible for increasing the mutation rate of the specific gene (which increases the chance of bringing about a variant that will be able to produce the necessary amino acid) is itself heritable, then the conclusion must be that adaptive changes can arise not only from natural selection of random (though "fit") DNA, but also from the action of evolved internal systems that generate non-random "guesses" in response to environmental challenges. Chance will indeed favor the prepared genome. "Rather than being restricted to contemplating a slow process depending on random (i.e., blind) genetic variation and gradual phenotypic change," Jablonka and Lamb quote the geneticist James Shapiro, "we are now free to think in realistic molecular ways about rapid genome restructuring guided by biological feedback networks."

I am a lay generalist, so be kind, thx.