> This is the idea that GP is responding to - clearly there must be some biological basis for race, if an AI can determine race from an x-ray.

Not necessarily; they could easily reflect societal differences. Bone density could be affected by diet, or medical care received, or environmental factors in poor neighborhoods, which might easily vary by race without there being a genetic cause for that variance.

If it were a simple "all black people have a bone density of 3; all white people have a bone density of 2" you could pretty solidly conclude a biological component, but we're in the realm of small variances and probabilities that confound things quite a bit.

I think the most likely explanation for these results is something like https://techcrunch.com/2018/12/31/this-clever-ai-hid-data-fr..., personally. Especially with the 8x8 pixelation example.

There is a massive difference between there being a biological basis to some of the phenotypes associated with racial categories and there being "biological meaning" to identifying races.

"Black" represents a wide range of genotypes, many which differ more from each other than from "white" individuals and populations, even if there may be other tendencies like bone density and novel genetic features that appear more commonly or exclusively in some subsets of the "black" population. The skin colour phenotype being (usually) darker just happens to be very easy to notice and have acquired a lot of socially constructed meaning. Except in the narrow context of skin tones, it isn't biologically meaningful to consider "black" people as a particular group though, particularly not compared to more specific genetic markers that don't have the same socially constructed meaning...

The point of the article is that if you clustered people based on genetic or anatomical properties in a non-post-hoc way, you would not end up with the same system of racial categories that are commonly used in the USA (or indeed any other country). As another poster has pointed out, the most striking example of this is the category 'Latino', which while often treated as a 'racial' category obviously has no biological basis.

This does not entail that no biological traits are correlated with race – biological traits are correlated to varying degrees with all kinds of subgroups of people. It does, however, mean that racial categories have no scientific basis.

To expand on this, imagine a Martian scientist studying human biology in isolation from human culture. Such a scientist would not subdivide humans into groups that match common racial categories, as these groupings are arbitrary from a biological point of view.