Race is not just a word for different breeding populations of humans. The dilution of its meaning into something so innocuous is ahistorical, in fact it contradicts what was claimed to be the reality of race just decades ago. It's a political concept first and foremost.
No biological theory predicts races. Races are categories rooted in historical economic exploitation and domination that are a posteriori fitted with whatever truthy pseudoscientific justification is catchy at the time. Any categories of humans that biological measurements would come up with would hardly match racial categories. Perhaps the most racialized group that has distinct biological markers are Ashkenazi jews. However, the relation between Ashkenazi jews, Sephardic jews, and ethnic Arabs is very strong.
P.S. A review of the legal history of race in colonial America: https://sph.umd.edu/sites/default/files/files/Harris_Whitene...
Actually, there very much are.
I think what you're trying to say is that not all black people have all the "black people genetic markers," and likewise for other groups. This is true, but this is not necessary to distinguish well-defined groups.
Family resemblance is a philosophical idea made popular by Ludwig Wittgenstein
It argues that things which could be thought to be connected by one essential common feature may in fact be connected by a series of overlapping similarities, where no one feature is common to all.
to quote my own post - well documented taxonomic differences between human races.
Or are you talking about biological differences as they correlate with geographic locality?
"Heaps don't exist because you can't prove an ironclad boundary between heaps and non-heaps."
"Tallness isn't a thing because you don't have a firm, binary definition of when someone is tall."
I am hesitant to recommend it because I have not read much critique of its central points. But I think it's good.
But even so the human genome is not continuously distributed, even if the difference is linear with distance, simply due to the fact that humans are not continuously distributed geographically. You can't handwave oceans and mountains away.
The main criticism of clustering is that the hierarchy of clusters that you obtain depend on the distribution of your samples, and that we currently do not have a good uniform sampling of human DNA. In short clustering can tell you reliably if someone is Irish or Italian, but may falsely identify the french as italian if there are not enough samples for french people.
1. Race as a social construct. It does exist in that capacity - as an extreme example Irish were not considered "white" in America (google for some "hilarious" images from "back in the day").
2. Race as a biological reality. This is a touchy subject for a variety of reasons. But that doesn't mean that well documented taxonomic differences between human races are "fake". They do exist and are more than "skin deep" - things like bone density, cranial capacity, maturation etc etc. Ask your dentist if he can tell by looking at someone's jaw x-ray whether it belongs to an east asian or sub-saharan african.