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Comment by mcphage | Hacker News Reader

> If you map every human genome in some space, there will be clusters. This is race.

There isn't a reason to think that those clusters would in any way map on to how we culturally, currently talk about race. Nor is there a single, well-defined way to cluster human genomes plotted in some very high dimensional space.

> You can use that argument to say there's no difference between trees and bushes

That's actually a perfect example. We have a word in English—"tree"—that refers to a large number of different species of plant. And you could plot plant genomes, and do a cluster analysis on them. But there will be no cluster that corresponds to the english word "tree". Genetically, there isn't a single "tree" ancestor, that all trees descended from. Instead, what we call "tree" evolved repeatedly at different points in time, and so no matter how you cluster the genes, what we refer to as "tree" will always be spread out among different clusters.

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> There isn't a reason to think that those clusters would in any way map on to how we culturally, currently talk about race.

Of course there is. However loosely, "cultural race" is linked to "genetic race".

Regardless, the post I replied to said "Race isn't even real genetically speaking".

> Nor is there a single, well-defined way to cluster human genomes plotted in some very high dimensional space.

There's very clearly an simple way to talk about genetic differences between groups. I don't know if there's a "single, well-defined way" but there doesn't have to be.

> That's actually a perfect example. We have a word in English—"tree"—that refers to a large number of different species of plant. And you could plot plant genomes, and do a cluster analysis on them. But there will be no cluster that corresponds to the english word "tree". Genetically, there isn't a single "tree" ancestor, that all trees descended from. Instead, what we call "tree" evolved repeatedly at different points in time, and so no matter how you cluster the genes, what we refer to as "tree" will always be spread out among different clusters.

The point I was making with the trees/bushes aside had nothing to do with whether we define trees genetically. It had to do with the fact that "fuzzy boundaries" or "lack of a single, well-defined boundary" isn't a good reason to discard a distinction.

Moreover, humans only evolved once.

It makes intuitive sense, but intuition is often misleading and deserves to be double checked.

In this particular case, while there does exist a set of alleles against which you can cluster populations in a way that maps roughly to the set of races we define socially, that only represents < 10% of the genetic variation across populations. Basically, that means you need to arbitrarily toss out > 80% of the dimensionality of your data for that clustering to meaningfully map against what we socially construe as "race".

This casts a large shadow on the idea that the genetic notion of "race" can serve as support for using the social notion of "race" as a means to treat anyone differently. You may be correct in the strictest technical sense, but the link is so tenuous that it can't really be used for anything useful.

"Race is a social construct" is a bit of a misnomer. The proper formulation should probably be something like "Race is only meaningful because we socially decided to make it so."

> In this particular case, while there does exist a set of alleles against which you can cluster populations in a way that maps roughly to the set of races we define socially, that only represents < 10% of the genetic variation across populations. Basically, that means you need to arbitrarily toss out > 80% of the dimensionality of your data for that clustering to meaningfully map against what we socially construe as "race".

This doesn't make sense to me. Can you provide more information?

I think you're referring to the fact that genetic differences between individuals within a group are larger than differences between groups. But that does not invalidate the differences between groups, or mean that we have to make "arbitrary" decisions to measure those differences.

I don't agree with the rest of your post but don't see the point of going into detail.

> I think you're referring to the fact that genetic differences between individuals within a group are larger than differences between groups

But that's the rub though: How do you define that there are groups in the first place? There is no way to land at our socially-defined set of races via objective means.

How do we differentiate between yellow and orange? The spectrum of colors is a continuum. Is the difference between yellow and orange not real?

> Is the difference between yellow and orange not real?

"Yellow" and "Orange" are words, not facts about the universe. They correspond (loosely) to physical observations, at least when it comes to perceived colors (there are plenty of optical illusions which reveal the vast gulf between 'the color a thing is' and 'the color we perceive'). So I don't really know what you mean by "real" here, but is it an objective fact? No.

> "Yellow" and "Orange" are words, not facts about the universe.

That's a philosophical position called nominalism. You can be a nominalist but other people disagree.

Right, the difference between what we call "yellow" and "orange" corresponds to objective physical properties. I could reject the way we have decided to group these differences, but the existence of different wavelengths seems to be a fact about the universe.

The different wavelengths is a fact about the universe, but there is nothing about the wavelengths themselves that makes one “yellow” and one “orange”. That’s all added by us culturally.

I think you're begging the question here. If you look at the differences between DNA, there will be clusters (because some people are more closely related than other people). These clusters are the groups I'm talking about.

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