What sort of discussion can we have about species identification regarding human phenotypes?

Take mockingbirds, for example, they all look nearly identical. Sure with very careful study of their individualities you can tell they are all not clones, but from ten paces…It’s tough.

This seems to be the same with many other species, with little exception.

One exception I see is humanity. We are all very different. Fathers don’t exactly look like sons…etc.

Now, I know I am treading on delicate ground, but it is just an observation.

Some of the species that I notice have similar issues are the domesticated animals.

Are our physical differences a result of some sort of domestication?

Help.