My old dog was a basset. And now there’s a bulldog in my house. I’m not sure how dogs happen, but they do.
This is what these breeds (pretty “over-bred” breeds) look like inside, and what they look like bred together.
It’s from The genetic and endocrinic basis for differences in form and behavior : as elucidated by studies of contrasted pure-line dog breeds and their hybrids, a book on heredity and anatomy – especially with generations of big heads and tiny legs.