>
>
> Uncle Davey wrote:
>
> > Has anyone done any work on this topic?
> >
> > It seems to me as though the 'wild forms' of animals tend to have the
> > dominant characteristics. When a wild boar mates with a pig, the
offspring
> > have more the shape of a wild boar, there is no fattening them up like a
> > domesticated pig, and so the farmers hate when that happens.
> >
> > Can we see a general tendency that wild characteristics are dominant and
> > ones bred in are nore recessive?
>
>
> Yes, to a degree. Though I'm not sure it accounts for the phenomenon you
> describe. Recessive mutations most commonly are recessive because they
> create a non-functional protein, or no protein at all. So in combination
> with an allele that does create a functional protein, we get a "normal"
> phenotype. Since there are more ways to break a gene than to fix it,
> many mutations are recessive. Breeders work with what they get, and
> sometimes the phenotype produced by rendering a gene non-functional is
> useful in a domestic animal. Thus many of the differences between
> domestic animals and their wild ancestors are probably recessive to the
> "wild type" alleles. On the other hand, many of the traits important to
> breeders are polygenic and quantitative, and the domestic breed has been
> assembled slowly by accumulating alleles at lots of loci that push the
> phenotype all in the same direction. Mixing this with a wild type will
> push the phenotype toward the mean. If, for example, some character
> state, call it A in a domestic animal is influenced by 10 loci eac with
> two alleles A and B, the domestic animal would have a genotype of
> AAAAAAAAAA, while a wild type would be a random mix of As and Bs,
> perhaps tending around 50% each, e.g. AABABBBAAB. A first generation
> hybrid would have around a quarter Bs and might look like a wild type to
> you.
>
I see. It looks like you're saying yes, but with qualifications.
In humans, blond hair is like a recessive characteristic, and dark hair is a
dominant one. Is that because humans came out of Africa? Were humans all
dark haired first, and some became blond later?
And if there's a functional protein in dark hair, why did we lose it, if
it's functional?
Uncle Davey
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