“Without at least heterozygosity for the health disorders associated with the mutations, Ashkenazim are no more intelligent, in the aggregate, than non-Ashkenazy Jews.”
Retired, you’re wrong. The largest hypothesized effects of the disease alleles would be only a small fraction of the Ashkenazim advantage: they just aren’t frequent enough. If you had a selective pressure for IQ, then it would affect all IQ-influencing alleles, reducing the frequency of rare variants with negative effects (Ashkenazi have lower rates of IQ-reducing PKU alleles), changing the distribution of allleles responsible for normal variation, etc. The Ashkenazi genetic diseases just happen to be visible because of their medical consequences. For instance, there may also be alleles that cause miscarriage (reducing parental fertility) or disrupt implantation in homozygotes but boost cognition, and we wouldn’t know.
“Without at least heterozygosity for the health disorders associated with the mutations, Ashkenazim are no more intelligent, in the aggregate, than non-Ashkenazy Jews.”
Retired, you’re wrong. The largest hypothesized effects of the disease alleles would be only a small fraction of the Ashkenazim advantage: they just aren’t frequent enough. If you had a selective pressure for IQ, then it would affect all IQ-influencing alleles, reducing the frequency of rare variants with negative effects (Ashkenazi have lower rates of IQ-reducing PKU alleles), changing the distribution of allleles responsible for normal variation, etc. The Ashkenazi genetic diseases just happen to be visible because of their medical consequences. For instance, there may also be alleles that cause miscarriage (reducing parental fertility) or disrupt implantation in homozygotes but boost cognition, and we wouldn’t know.