There's been studies which show ethnic groups in China differ substantially in average IQ scores. Yet, racialists will group them all together as "Mongoloid". Even looking at Lynn's papers shows some of these marked differences e.g. Daur differ in average IQ by 9 points to Han; Ewenki, by 11 points (Lynn & Cheng, 2013).
The issue is less with the heritability of IQ, but that racialists adopt an obsolete typological classification of three races ("White" or "Caucasoid", "Yellow" or "Mongoloid", and "Black" and "Negroid") which forces diverse populations into the same category.
If Lynn, Rushton etc., just did their research on ethnic groups without arbitrarily categorizing them into oids, no one would have a problem.
Also: Darwin and Blumenbach never defined race as just "ancestry". Mikemikev has a tendency to lie.