It's really only an accident of history that there's such a sharp division between humans and other animals in terms of intelligence and advanced culture. If we'd developed technology while there were still intermediate species like Australopithecus and Homo Habilis around, it would have lent greater clarity to the fact that we are just a branch of a varied tree.

Choose any random cow or other livestock animal. You and Bessie have at least one common ancestor.

Yes. Or, more properly, equating pigs and cows with human beings. I've yet to see a logical reason not to.

How about insects?

Pigs and cows are mammals with central nervous systems much more similar to ours than any insect.

I don't eat them either.