> 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.
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):
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.
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.
I think this is the thing people misunderstand about race being a social construct, is that race is a bucket, by nature there need to be correlations between people in that bucket in order to actually place people into that bucket in the first place.
There will likely be other correlations between people in said bucket, who are in this cause usually more closely related and share more recent common ancestors.
The size of that bucket and how we put people in it is arbitrary, but the fact that correlations exist when you put people in buckets isn't.
This is another problem with species - where is the transition where one species evolves into another?
Is there any definition of race where, given two people, you can apply some criteria to determine whether or not they are the same race? The criteria can't be "look at the definitions of each race and categorize the two people" because that's circular, how were those particular categories chosen? With species, you can determine that a bird and a fish are different species without knowing what birds and fish are.
Edit: but even if I did agree with the definition, if "race" is as useful a category as "species" despite being socially constructed, all of the people calling race a social construct have utterly failed to make the case that we should stop using it.
The same is true of "species". Last I checked, there were at least 24 different definitions of "species", all of which have some overlap and none of which are perfectly precise. You don't see people going around saying "species is a social construct". Then again, maybe they will soon, I suppose anything is possible these days.
That said, you are correct that "race" is merely a rough statistical correlation for some cohort, not some precise measure. If we can categorize more precisely, then we should, and we only fall back to "race" as a last resort (if it's applicable).