Two ways to put the magnitude of race differences into perspective is to compare it to gender and family relations. This uses Fst distances which simply means proportion of variance between a population compared to the proportion of variance within.
For example, if the Fst distance between population A and population B was 0.15, that would mean that 15% of the variance was between the populations, while 85% was within the populations, or “common to both populations”.
An Fst value is, in practice, a kind of “inverse kinship coefficient”, or “anti-kinship”. You can multiply the Fst value by 2 and that is the “anti-kinship”.
For example, the kinship coefficient of a parent to a child is 0.5, while the kinship coefficient of the parent to a grandchild is 0.25, and the coefficient between two siblings is 0.5.
The Fst distance between Europeans and Africans is 0.166, which can be modeled as a kinship coefficient of -0.332.
Aunt, Uncle, Niece, Nephew 0.25
First Cousin 0.125
An explanation of why Fst functions as an “inverse kinship coefficient divided by 2” can be found in Henry Harpending’s paper, “Kinship and Population Subdivision”:
Race vs. Gender
The next way to put race differences into perspective is to model gender differences as an Fst distance.
Males and females differ due to the Y chromosome. Males have it, and the Y chromosome deactivates analogous genes on the X chromosome. The Y chromosome is only 458 genes, compared to approximately 22,500 genes on the genome.
Assuming every single gene on the Y chromosome replaces a gene on the X chromosome, that can be modeled as an Fst distance between males and females of 1.00, but only on 458 genes. This is because 100% of the genes on the Y chromosome are assumed to deactivate an analogous gene on the X chromosome. It’s an allele frequency difference of 100% but only on those genes.
When the fact that males and females are identical on the rest of the genome is taken into consideration, the Fst distance between males and females can be modeled as 0.021. The point of doing so is not because this is a useful fact, but to compare the magnitude of this difference to race differences.
This is assuming every single gene on the Y-chromosome differs from the analog on the X-chromosome it deactivates. For every gene this is not true about (where the Y-chromosome gene is the same as the X-chromosome gene), that will make the Fst distance between males and females smaller. So really 0.021 should be seen as a MAXIMUM.
Comparison Fst Distance
Europeans – Africans 0.166
Europeans – East Asians 0.097
Europeans- Amerindians 0.095
Males – Females (maximum) 0.021
In terms of magnitude, the race differences completely dwarf gender differences. However, gender differences are a “hard break” at specific sites, while the race differences are spread over the whole genome.
While the genders have a 100% allele (gene variant) frequency difference at 458 locations, the races will have something like an average 30% allele frequency difference at 7,500 locations.
So while race differences, in total genes differing, completely swamps gender differences, it is more continuous in nature, whereas the gender differences are smaller in total, but typological.
But the point here is not to say one is more or less important than the other, it’s just to show how silly the claim “race doesn’t exist” is by putting it on the same scale at other commonly recognized genetic relations – family and gender.