[entee]

Race is often shorthand for ethnicity, and it's true that to a certain extent different ethnic groups have genetic differences of medical relevance. While variation within groups is generally larger than that between groups, that doesn't mean ethnicity is medically useless as data point. Classic examples are among those the OP listed. The most visible are probably lactose tolerance (significantly more common in Europe and cattle-herding populations) and alcohol dehydrogenase (also know as Alcohol Flush Reaction). There are many others and we're likely to find many more.

Medically important genetic differences between ethnicities exist, but it's important to note the limits of this analysis. Usually these are fairly low-level traits, i.e. different enzyme activity, and it's critical not not over-extend the logic to more complex emergent traits such as intelligence or others where clean biochemical links are suspect. Saying a certain set of constraints changed the way certain enzymes work in a given population is not the same as saying this group is better than another group.

[jerf]

"it's true that to a certain extent different ethnic groups have genetic differences of medical relevance."

It's just plain true.

"While variation within groups is generally larger than that between groups"

That line is for the big traits, like intelligence, strength, etc. Those are made up of many, many genes, and I've even seen a couple of recent articles that suggest the answer to the question "which genes affect intelligence?" may well be "all of them". When it comes to specific genes, though, the incidences can be correlated very strongly to ethnicities/races.

If you're having trouble squaring that with your political pieties, bear in mind that it's actually all correlations, not causations. The real cause of the genes an individual has is their literal ancestry (i.e., not their "race" but their exact ancestry, the exact humans and indeed even the exact genes carried by the relevant eggs and sperms), and it isn't that surprising that that correlates strongly with something else that is very tied to ancestry. But really, it's a separate process.

There is a de-novo genetic mutation my wife has. She didn't get it from either of her parents. (You know what I mean.) The races of all the individuals involved have nothing to do with the fact that one of our children also has it and one does not.

It's sort of important that we not freak out about "races" showing up in medicine; is it more important that people get correct medical treatment and live better lives and at times just plain live even if we can only use a crude tool for a while, or that our particular delicate political beliefs be left unchallenged? I know which I choose.

[lgessler]

> Race is often shorthand for ethnicity

Huh? In medical contexts I've always understood race as a person's genetic background and ethnicity as a person's cultural background. The two often don't align as many might expect: an adopted child, for example, could be racially South Asian but ethnically French because they speak French, enjoy French food and culture, perceive their self as French, etc.

[entee]

That's maybe true but in that case also quite incomplete and doesn't actually conflict with my point. Ethnicity is a readout of where that person grew up, those cultural touchtones reflect that you have a bunch of people living in the same geographical area. These people scramble their genes together, but because they're in the same area, they would naturally begin to diverge genetically from those in other areas.

You're right that ethnicity and the common definitions of race (i.e. skin tone, hair color/texture, dominant facial features) don't always correlate as well as expected, but that doesn't stop it from being used that way. Another example in addition to yours would be someone who is north african and someone who is south african may have quite different tolerance to lactose because of different prevalences of cattle herding in those regions of the world (Lactose tolerance arises very quickly when humans raise cattle). Still an outside observer would label them both "Black", despite their ethnicities and genetic makeups being different.

In short, ethnicity/race/genetics are all correlates but not absolutes. You have to do a follow-up test, you have to be careful in your assumptions or you'll make a mistake.

[TooBrokeToBeg]

> I've always understood race as a person's genetic background and ethnicity as a person's cultural background

I've heard that maybe once every 20 years. It just isn't the way the language is used. It may not be anyone's fault, but the conflation is the way it is AFAIK.

[irrational]

Are you sure you mean ethnicity? My understanding is ethnicity refers to things like language, perhaps nationality, regional culture, etc. I have friends who have the same ethnicity as myself: we speak the same language, eat the same foods, share the same culture, etc. but 100% of their ancestors up to their parents are from Samoa. So, it would seem that they would be affected by medical things that are specific to Pacific Islanders even though their ethnicity is not Pacific Islander.