I'm not sure what you mean by "half-breeds". Are you thinking of something like a cross between a duck and dog, or between a shark and and an elephant?If evolution is a fact, and happens so slowly, then why aren't there half-breeds (missing links) still alive today? They should still be walking the Earth.![]()
Evolution doesn't work like that. Ducks and dogs are different species. They do not interbreed. That's why they are different species, at a definitional level.
All dogs evolved from wolves. Are there intermediates between dogs and wolves? Think about wild dogs, as a rough example.
You might put a wolf and a poodle side by side and think they are very different, and that one couldn't possibly be related to the other. Nevertheless, there's a recent (in geological terms) common ancestor of all poodles and all wolves that are alive today. Poodles, of course, have not just been naturally selected. We humans have deliberately messed with their evolution. We created poodles from wolves.
Speaking more generally, though, here's where your thinking is going wrong: all modern species evolved from earlier species. Think about the common picture of the "tree" of life. In that picture, all modern animals, for example, are leaves at the outer ends of various branches of the tree. If we follow inwards from the leaves to the recent twigs, to the older and larger branches, to the trunk, everything is joined together. But the question you're asking is like asking why there are no leaves half way between two given leaves on separate outer branches of the tree. There's zero reason to propose that there should be a "branch" half way between dogs and ducks, for example. What is true is that if we were to follow the dog branch back towards the trunk of the tree (back in time), then at some point it would join with the duck branch - the point where the species that led to modern dogs and modern ducks branched away from one another.
You can't deny that there are intermediates. You are not identical to your father, who is not identical to his father. Your father is a clear intermediate between you and your grandfather. Continue the small variations over thousands of generations and ask yourself why you would expect your distant ancestors to look the same as you.