Nope, I can't prove it, and neither can the biologists for that matter. But it is a pretty well accepted theory. Could be interbreeding is still taking place as well, since we have a large coyote pop. but limited wolf pop.

I really doubt a full blooded coyote could reach 115 pounds, but maybe it's remotely possible. The one in the pic really looks to me like it has some wolf or malamute in it though.