Oh for the love of god. Your contribution to the discussion of an extremely complicated topic is the academic bulwark of Wikipedia. And by the way, the first sentence in the linked article is: "The intelligence of Jews relative to other ethnic groups has been an occasional subject of scientific controversy." Hardly a shining endorsement of your views. And anyway, the intelligence of a particular group is the shakiest way to support your argument, since there's not even a consensus of what intelligence is, much less how to best measure it.
But as for the actual genetic "basis" of the "race realist" argument:
Whatever you want to call it then.
That's the thing, though. "Race" is nothing but a term we made up. When I say it doesn't exist, I don't mean that "race" is the wrong word for some concept; I mean it really is not anything real. We can divide the human race into any number of "races", but here's the problem: If you want to do that, the first step of the requisite statistical analysis of human genotypes is to determine how many groups you want to divide humans into. If you want to divide humans into three races, you can come up with three groups, but there was never anything that said there are three or five or twenty races that humanity should be divided into. And that alone strongly suggests that "race" doesn't exist outside the mind of humans.
Do ethnic groups exist?
Again, same as above. We can identify genetic similarities within populations, but these are incredibly fluid. The closest genomic researchers come to speaking of anything remotely similar to "race" or "ethnicity" is when we use haplogroups to identify certain populations. But this essentially just involves identifying a population by a certain shared genetic marker. It again gives no basis to divide humans into races or ethnic groups. What's more, there's actually more genetic variation within "racial groups" (once you divide humans into an arbitrary number of them) than between them. That means that of the rather small amount of genes that differ between humans, the vast majority of them can't be connected to any particular populations. It just so happens that the very few genes that
do
regularly differ between populations include highly-noticeable ones like skin color. But that's maybe 10 out of the 20,000 human genes.
Do "people with subsaharan african phenotypes" exist?
No, not really. Because "Sub-Saharan African" isn't a phenotype. We can look at populations in Sub-Saharan African populations and identify genetic commonalities, but I guarantee you (because, you know, this has already been done) that you won't find a grouping that conforms to your conception of race. In fact one of the major ways in which we can genetically group populations involves comparing single-nucleotide polymorphisms (SNPs), which are locations in non-coding regions of the genome known to be variable between populations. But note the phrase
non-coding. Without an in-depth example of the mechanics of eukaryotic genomes, suffice it to say that these SNPs have absolutely no effect on an organism's phenotype. Meaning most human variation is completely independent of phenotype, which speaks to remarkable phenotypic similarity between all humans. Like I mentioned, it only
seems
like there's more variation than there actually is because we can see things like skin color.
I say "there is a strong correlation between people having subsaharan african phenotypes and a low IQ, and adoption studies show both of these traits to be predominantly hereditary"?
Whether or not IQ (and, by the way, the IQ test has long been known to be culturally biased and is by no means universally accepted by psycologists) is hereditary is a matter of debate. From what we know, the general consensus is that at least part of intelligence is genetic, but there's a vast amount of intelligence that's not accounted for by heredity.
The fact that you're claiming that blacks have a lower IQ than other "races" probably means you've been reading
The Bell Curve
or other such pseudoscientific drivel. Even if we accept this tendency to be genuine, and even if we accept the IQ test to be a valid indicator of intelligence (and again, there's not even agreement on what intelligence is), this result would still mean practically nothing. Take any amount of arbitrary groups, apply some random assay to them, and you'll be able to rank them from highest to lowest. It proves nothing.
In Summary:
The fact is, everything we know about human genetics tells us that race does not exist. Humanity expresses practically no population-based genetic differentiation. Those genes that do differ between populations don't support differences on the level purported by "race realists" - they're things like skin color and lactose sensitivity. Practically all of what "race realists" hold up as evidence (at least that which isn't completely fabricated) of race can be explained by cultural background. And if you don't believe me, feel free to ask pretty much any biologist. That race is entirely fictitious is not a controversial position - it's the only possibly conclusion from the wealth of available data. For a deeper explanation of the issues I addressed here and more information on the science behind them, there is a great YouTube video series (videos
1,
2, and
3) made by a biologist, with relevant scientific literature cited.
Edit: One rather poignant fact I forgot - The vast majority of human genetic variation is entirely confined to Sub-Saharan Africa.