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Re: inbreeding as a species-accelerant ; NOVA "Decoding Neanderthal"
#198 Rockthrowing theory book
Posted:
Jan 25, 2013 3:37 AM
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On 01/25/2013 01:39 AM, Archimedes Plutonium wrote:
> Basically I am just simply asking for what mathematical advantage for
> mutations arises for inbreeding. I do not know if any biologist has
> researched this question. The question of how much faster or how much
> more mutations accrue when a population of a species has inbreeding.
> Such as when 1 male and 1 female are stranded on a island and up to
> those 2 individuals to keep their kind growing. So there is much
> inbreeding. And not outside mating. So that all generations on the
> island trace their ancestors back to those starting 2.
>
> Compare that population with an equal sized population that has no
> inbreeding.
>
> I would hazard to guess that the mutations of the inbreeding
> population would be far ahead of the non inbreeding population.
>
> And I think this is how so many islands that are isolated from their
> mainland have so many different species that the mainland does not
> have, is because of what I call the species accelerant of inbreeding.
>
> So that Neanderthal was two Africans that migrated north out of Africa
> some 400,000 years ago and because of inbreeding ended up as different
> species of the Africans who migrated enmasse some 60,000 years ago.
>
> So that the Clovis man who migrated to the Americas, either out of
> Asia or Europe some 15,000 years ago, if Clovis man had been a single
> 1 male and 1 female and populated the Americas, that by the time of
> Columbus would have found, not the same species of Homo sapiens, but
> perhaps a different species. So here we have a sort of scientific
> prediction or question, of how many Clovis people migrated to the
> Americas some 15,000 years ago so that their genetic stock was
> sufficient to not mutate too much so that by the time Columbus
> arrived, they would still be the same Homo sapiens species.
>
> So we need some biology research into what sort of mutation rate is
> increased in populations with inbreeding versus populations of
> noninbreeding.
>
> And in sociology we can recognize the problem of the American Indians
> in that they needed tribal interactions with other diverse tribes
> because of inbreeding.
>
> Usually inbreeding brings out deleterious mutations, and rarely does
> it bring out advantageous mutations.
>
> Now I would be deeply surprised if no biologist has done research on
> this before, of extracting a number for mutation rate in a
> noninbreeding population and a mutation rate in a inbreeding
> population.
>
> So if we had such a numbers figure for this mutation accelerant and
> applied that numbers to Clovis Man, we may be able to roughly estimate
> how many individuals, male and female crossed over into the Americas.
[...]
Some common genetic diorders are single-gene recessive,
meaning that one good allele and one bad allele
makes for an Ok baby (a carrier), but two bad
alleles makes for a "bad" baby who exhibits or manifests
the disease linked to the "bad allele".
And two good alleles makes an Ok baby also.
That's for the genes carried on the non-sexual chromosomes.
For diseases single gene recessive on the X sexual
chromosome, one allele bad of the gene on the X-chromosome
makes for a "bad baby" if it's male, cause the male has
one X and one Y sex-chromosome. But a female baby with
two X-chomosomes and 1 good and 1 bad allele would be
an Ok baby, but still a carrier. This happens with
hemophilia, if memory serves me well.
The genes that make for a strong baby who will reproduce
with optimal number of off-spring is highly non-trivial.
Some game theory could be involved and there could be several
optimal fitness genomes; also, variation of gene pool could be
an asset for a loosely-bound tribe.
Maybe some models can say something about the optimal strategy
for an individual, like say considering marrying a second-cousin
by age 37 if all else fails. It's just speculation on my part
that such studies/simulations/models exist.
dave
--
dracut:/# lvm vgcfgrestore
File descriptor 9 (/.console_lock) leaked on lvm invocation. Parent PID
993: sh
Please specify a *single* volume group to restore.
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