"Christian R. Larsen" <crlarsen@hotmail.com> wrote in message
news:4643066c$0$90267$14726298@news.sunsite.dk...
> "Knud Larsen" <mafishmaskela@yahoo.invalid> wrote in message
> news:4642f674$0$21927$157c6196@dreader1.cybercity.dk...
>>> Det kan man ikke bare sige. Når man skal forklare forskellen mellem to
>>> individer eller to grupper, kan forskellen sagtens skyldes enten arv
>>> eller miljø. Et klassisk eksempel er to klonede blomster i et drivhus -
>>> den ene får kunstgødning, den anden kun vand. De to planter er genetisk
>>> 100% ens, men den ene vil alligevel klare sig bedre end den anden.
>>
>> Et vanvittigt og reduktionistisk eksempel, - lyder som noget fra en
>> religiøs gruppes propaganda.
>
> Så burde det jo været let at komme med et modargument, frem for blot at
> kaste med beskyldninger.
Modargument for hvad? Jeg siger det er vanvittigt analogt at sige, - her
har vi to enæggede tvillinger, den ene ligger i en sort kælder hele sit liv,
den anden lever oppe i lyset og stimuleres intellektuelt, - så kan enhver
vel regne ud hvad udfaldet af "eksperimentet" bliver. Mao det siger intet
som helst, som almindlig sund fornuft ikke allerede ville vise.
>
>>> Som gruppe er de for det første ikke specielt ens rent genetisk, og for
>>> det andet er de - som gruppe - ikke nævneværdigt genetisk forskellige
>>> fra befolkningen i øvrigt. Den indlysende årsag er, at vi flittigt har
>>> blandet gener med hinanden gennem årtusinder. Så det er der sådan set
>>> intet underligt i.
>>
>> Så det er derfor vi nu alle har samme hudfarve, hårfarve og øjenfarve,
>> samme tendens til sukkersyge osv
>
> Her går jeg ud fra, at du mener den danske befolkning internt - og du har
> da helt ret: Denne meget homogene gruppe har forskelligt udseende og
> forskellig grad af tendens til sukkersyge.
Pakistanere har en utrolig stor udbredelse af sukkersyge, er det
kontroversielt?
>
>> Arabere især er utrolig indavlede,
>
> Så det rammer mindst en 10-20% af dem eller hvad?
Indavl? Det rammer mange flere, 25 - 60% i de arabiske lande.
Her er lidt om genetiske fejl:
Genetic disorders in the Arab world
Lihadh Al-Gazali, professor in clinical genetics1, Hanan Hamamy, professor
in human genetics2, Shaikha Al-Arrayad, consultant geneticist3
1 Department of Paediatrics, Faculty of Medicine and Health Sciences, United
Arab Emirates University, Al-Ain, United Arab Emirates, 2 National Center
for Diabetes, Endocrinology and Genetics, Amman, Jordan, 3 Salmaniya Medical
Complex, Ministry of Health, Bahrain, Kingdom of Bahrain
Available evidence suggests that congenital and genetic disorders are
responsible for a major proportion of infant mortality, morbidity, and
handicap in Arab countries.1-3 The population of the region is characterised
by large family size, high maternal and paternal age, and a high level of
inbreeding with consanguinity rates in the range of 25-60%.1 2 4 w1 Certain
disorders are common throughout the Arab world, including
haemoglobinopathies, glucose-6-phosphate dehydrogenase deficiency, different
congenital malformations caused by recessive genes, and several metabolic
disorders.1 2 Other recessive disorders cluster in certain groups and
subpopulations.1 2 5 Genetic services vary in extent and coverage in
different Arab countries, but mostly they remain patchy, selective, and
inadequate.
...-
Why are genetic disorders common in the Arab world?
Available data suggest that genetic and congenital disorders are more common
in Arab countries than in industrialised countries; recessively inherited
disorders account for a substantial proportion of physical and mental
handicap.1-3 6 Several factors may contribute to the high prevalence of
genetically determined disorders:
* High consanguinity rates—25-60% of all marriages are consanguineous,
and the rate of first cousin marriages is high.
-----------------------------
Fra "Nature":
I have now examined the effects of inbreeding on cognitive performance in an
Arab population with a high rate of consanguinous marriage which minimised
the distortions due to non-genetic variables. I show here that offspring of
unrelated parents performed better than offspring of first-cousin marriages
in intelligence and achievement tests administered at grades 4 and 6. The
lowest level of performance and a higher variance were found for offspring
of double-cousin marriages. The inbreeding depression found in this study is
consistent and cannot be explained by the effects of socioeconomic status.
---------------------------------------
Og lige en bid om hvorfor fætter-kusine ægteskaber har været udbredt:
Just as the inbred have fewer unique ancestors than the outbred, they also
have fewer unique heirs, helping keep both the inheritance and the brothers
together. When a herd-owning patriarch marries his son off to his younger
brother's daughter, he insures that his grandson and his grandnephew will be
the same person. Likewise, the younger brother benefits from knowing that
his grandson will also be the patriarch's grandson and heir. Thus, by making
sibling rivalry over inheritance less relevant, cousin marriage emotionally
unites families.
The anthropologist Carleton Coon also pointed out that by minimizing the
number of relatives a Bedouin Arab nomad has, this system of inbreeding
"does not overextend the number of persons whose deaths an honorable man
must avenge."
Of course, there are also disadvantages to inbreeding. The best known is
medical. Being inbred increases the chance of inheriting genetic syndromes
caused by malign recessive genes. Bittles found that, after controlling for
socio-economic factors, the babies of first cousins had about a 30% higher
chance of dying before their first birthdays.
The biggest disadvantage, however, may be political.
Are Muslims, especially Arabs, so much more loyal to their families than to
their nations because, due to countless generations of cousin marriages,
they are so much more genealogically related to their families than
Westerners are related to theirs? Frank Salter, a political scientist at the
Max Planck Institute in Germany whose new book "Risky Transactions: Trust,
Kinship, and Ethnicity" takes a sociobiological look at the reason why Mafia
families are indeed families, told me, "That's my hunch; at least it's bound
to be a factor."
------------------------------
>
>>> Men når jeg nævnte det faktum, at indvandrerbørn i indvandrertunge
>>> skoleklasser klarer sig dårligere, så er det netop for at påpege, at
>>> miljøet må have en særdeles kraftig indflydelse på elevernes kunnen.
>>
>> Dårligt "bevis" - det afhænger jo helt af *hvor* stor effekten er.
>
> Den er stor - det var derfor, jeg skrev det.
Du har ikke kvantificeret denne effekt, og den kunne stadig evt. bare være
relativ dvs at disse elever stadig scorer langt lavere end andre.