Peter Ole Kvint wrote:
> Flemming Svendsen skrev:
>> Hvad man dog hitter ud af:
>>
>> "En enkelt mutation i menneskehedens udvikling ses i dag i øjnene på
>> blåøjede mennesker.
>> De fleste mennesker i verden har brune øjne, og det er også den
>> oprindelige øjenfarve hos mennesket.
>>
>> Men der findes også rigtigt mange blåøjede mennesker, og en
>> genforsker, Hans Eiberg fra Panuminstituttet, har nu opdaget at det er
>> en mutation i de blåøjedes DNA der i tidernes morgen har blokeret for
>> produktionen af det brune farvestof melanin der giver brune øjne.
>>
>> Denne mutation er kun sket én gang i hele menneskehedens historie, så
>> alle mennesker med blå øjne har således én og samme forfader, siger
>> Hans Eiberg.
>> Det anslås at denne DNA-ændring fandt sted for ca. 6000 - 10.000 år
>> siden"
>>
>> (Tyvstjålet fra en spalte af Peter Geisling i min kones ugeblad
>> Flemming Svendsen
>>
> Der er bare det at man kender eksempler på at blåøjet forældre får børn
> med brune øjne. Så er må være flere gener på spil end en mutation.
LOL
the discussion is of a historical mutation
when we came out of Africa dark skin colour and brown eyes were
essential protection against sunlight
white hair and pink eyes see wiki:-
Albinism (from Latin albus, "white"; see extended etymology) is a form
of hypopigmentary congenital disorder, characterized by a partial (in
hypomelanism, also known as hypomelanosis) or total (amelanism or
amelanosis) lack of melanin pigment in the eyes, skin and hair (or more
rarely the eyes alone).
Albinism results from inheritance of recessive alleles. The condition is
known to affect mammals (including humans), fish, birds, reptiles, and
amphibians.
While the most common term for an organism affected by albinism is
"albino" (noun and adjective), the word is sometimes used in derogatory
ways towards people; more neutral terms are "albinistic" (adjective) and
"person with albinism" (noun).
Additional clinical adjectives sometimes used to refer to animals are
"albinoid" and "albinic".
About 1 in 17,000 human beings has some type of albinism, although up to
1 in 70 is a carrier of albinism genes.[11]
http://en.wikipedia.org/wiki/Albinism
Lighter hair colors occur naturally in Europeans, and as rare mutation
in other ethnicities[3]. In certain European populations, however, the
occurrence of blond hair is very frequent, and often remains throughout
adulthood. The hair color gene MC1R has at least seven variants in
Europe and the continent has an unusually wide range of hair and eye
shades.
Based on recent genetic information carried out at three Japanese
universities, the date of the genetic mutation that resulted in blond
hair in Europe has been isolated to about 11,000 years ago during the
last Ice Age. Before then, Europeans mostly had darker hair and eyes,
which is predominant in the rest of the world.[3]
Blond (also spelled blonde, see below) is a hair color found in certain
people characterized by low levels of the dark pigment eumelanin. The
resultant visible hue depends on various factors, but always has some
sort of yellowish color, going from the very pale blond caused by a
patchy, scarce distribution of pigment, to reddish "strawberry" blond
colors or golden brownish blond colors, the latter with more eumelanin.
http://en.wikipedia.org/wiki/Blonde
so today genes
but how did the genes arise?
Hugh W
--
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