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0 pointswwalexander4y ago0 comments

The second sentence of the Wikipedia article for “species” reads:

> A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction.

This is the definition I’ve always heard, and it’s certainly more rigorous than any definition of “race” that I’ve encountered, and makes no reference to any arbitrary social constructs.

Conversely, the definition for “race” is explicitly arbitrary and social:

> A race is a grouping of humans based on shared physical or social qualities into categories generally viewed as distinct by society.

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5 comments · 1 top-level

naasking4y ago· 4 in thread

> This is the definition I’ve always heard

It's not as precise as you think, because fertility isn't transitive. Consider members of a species, M1, M2, F1, F2. M1 might be fertile with F1, M2 with F2, but M1 may not be fertile with F2. Are they all really members of the same species?

Read up on the species problem for more information (there are now 26, not 24):

https://en.wikipedia.org/wiki/Species_concept

wwalexanderOP4y ago

I can’t admit I have any qualifications to speak about biology, and I know HN is known for proposing reductive “solutions” based on oversimplified models of reality.

That being said, it seems to me that it makes sense that a species would include the entire connected graph whose nodes are members and whose edges represent the ability to have fertile offspring.

I found [1] which is an interesting example of a very large graph, but nevertheless, all the examples seem to be within altogether very similar groups.

I think a reasonable definition for casual use doesn’t need to require the graph of a species to be fully connected, only fully reachable.

There are certainly leaks to any abstraction of species, but they are empirical cases of exceptions. They don’t inject arbitrary social categories into the definition. Definitions of “race” have no empirical basis on which to be proved or disproved in the first place.

[1] https://en.m.wikipedia.org/wiki/Ring_species

naasking4y ago

> They don’t inject arbitrary social categories into the definition. Definitions of “race” have no empirical basis on which to be proved or disproved in the first place.

That's simply not correct. The literature abounds with all sorts of correlates with race, like propensity for sickle cell anemia, vitamin D deficiencies, susceptibility to alcohol, and morphological differences. These are just as empirically justified as any classification of species, and just as with species, not all of those properties need apply to every single member in that category.

So to the extent that we find "species" a meaningful category when applied correctly, then we should also find "race" a meaningful category when applied correctly. The key in both scenarios is to apply them correctly, and we should abandon them when we find more precise metrics.

That said, you are correct that there are also numerous cultural and social properties that are sometimes lumped in with race in a manner that we don't see with species, mainly because "species" hasn't been politicized. That doesn't imply that there's nothing "there" once you tune out that baggage.

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exporectomy4y ago

That doesn't work because the graph for humans would go all the way back to those ancient apes by many connected edges and back down to modern apes, making us all the same species.

This is another problem with species - where is the transition where one species evolves into another?

mcguire4y ago

IIRC, there are two species of birds, A and B, in the North Atlantic that cannot interbreed. But A can breed with C which has a range to the east, and C can breed with D again further east. And so on, around the arctic circle, until you get to Q which can breed with B.

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