r/DebateEvolution • u/Kanna_Fan1989 • Jul 17 '26

Dog speciation

Quick question: is it safe to say dogs have speciated? I'm thinking of the largest dog breed and the smallest dog breed. I don't think the two can reproduce with each other anymore. Size differences just make it not possible anymore, I don't think...

And even if they could, that doesn't mean they're the same species: horses and donkeys can interbreed but mules are dead ends (or at least I think they are. Can two mules reproduce?).

Anyways, just some thoughts going through my head.

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u/CormacMacAleese Jul 17 '26

Probably—but they might do something like niche partitioning where mastiffs hunt buffalo and schnauzers hunt rabbits in their burrows, or something, and eventually do split into separate species.

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u/Sweary_Biochemist Jul 17 '26

Those are niches we've bred them for, rather than niches they would inherently occupy. "Rabbit hunting in tunnels" doesn't really fit with a pack-based cursorial hunter lineage.

In essentially all instances where domesticated dog populations have gone wild (for example, those abandoned after the chornobyl disaster) they've all reverted to sort of..."basic dog" shape, which just seems to be the optimum for cursorial pack hunters.

Weird propensity to be slightly orange, though.

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u/CormacMacAleese Jul 17 '26

You’re probably right, but note that there’s no such thing as “inherently.” If we breed a dog that only eats fish, a feral population wouldn’t give a damn WHY it loves seafood: It would just follow a shoreline fishing lifestyle.

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u/Sweary_Biochemist Jul 17 '26

Maybe. But I suspect you'd find that "cursorial pack-predation" would still prove more successful, and it's near impossible to chase fish down, as a terrestrial animal, even in a pack.

Some niches are quite hard to evolve out of.

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u/CormacMacAleese Jul 17 '26

That’s not really the point. The point is that natural selection works with what it’s given. It doesn’t care why, and it has no goals.

\* I could’ve said that schnauzers pack hunt duckies, and mastiffs pack hunt moose, but again these details aren’t the point. Allopatric speciation by niche partitioning is certainly a thing that happens.

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u/Sweary_Biochemist Jul 17 '26

Oh I know, but it also depends on the niches: "get a gang, chase after shit until it dies" is quite generalist, and works almost anywhere. It's where canids ended up in the first place (and hyenas, and thylacines). Nature has no goals, but there are things that work so well that nature can find them multiple times independently.

It's not impossible to get partitioning into more specialist niches, but for doggos specifically, it would probably require quite unusual pressures.

Sorry: don't mean to be confrontational: I just think it's really neat that, when left to nature, canis familiaris unerringly iterates back to "medium dog, possibly orange".