Yes, and this is where my decades of rescue experience comes in.

With both dogs and cats, we can find what looks like clear crosses from two distinct breeds. I've seen litters of kittens where every one was different from the others. I've adopted pups who looked like one breed and by the time they grew up they looked like another. But... they were all different. And they all had clear breed traits that let me understand and train them.

Even purebreds got that way by abundant outcrossing!

We don't blend like milkshakes. Some of us take after mom's side, or dad's, are are ringers for the great-uncle.

I found that when it came to crafting my radical new diet, I used a theory that I should eat the way people do who live in places with a short growing season and herd livestock. This works for me. It's not going to work for everybody.

And that's the point. What if some of what makes us so different are the enzymes we inherited? That, as explained in the book Death by Food Pyramid, is what really determines what we can get nutrition from, and how much.