[Wolfstar]

If you could find evidence that either they could breed together or couldn't, then you would answer the question of whether they are separate species.

This is incorrect. Closely related species potentially can interbreed successfully. The key word is potentially. Examples of closely related, but different species that can interbreed include (but are not limited to) wolves and dogs, foxes and dogs, horses and donkeys, lions and tigers, sheep and goats, bonobos and chimps.

[heartwood]

Dog-fox hybrids are really dubious. Coyote-dog, sure.

I know someone who looks very neanderthal. Brow ridges, saggital crest, prominent nose and jaw, receding chin. Quite intelligent too.

[toast]

I stated they had to produce “fertile” offspring.
Donkeys and horses produce mules. They are not fertile.
Lions and tigers can produce offspring but they are not fertile.
Dogs are direct descendants of wolves. They are considered separate species but a Husky is a lot closer to a wolf than to a chihuahua.

The article talked of the 2 human species not being descendants.

[2 Kool 2 Be 4-Gotten]

The liger is pretty much my favorite animal.

[brytlea]

I think maybe they now consider dogs and wolves to be the same species.
susie