We are ONE people always evolving, hence, evolution which goes back millions of years. Have you guys heard of the “Continental Drift” and “Pangaea”? It’s really fascinating to see the puzzle of earth come together. We all dispersed to different parts of the world and adapted to its environment. This adaptation to the environment created the different races. Those who lived in warm lands like Africa and the Mediterranean developed more melanin turning their skin brown, black or olive so they’d be protected against the sun. For those in colder lands like Scandinavia didn’t need the melanin so their skin was fair. Now let’s take Othello, although a fictional character, was portrayed as a moor, and you all know that moors were a people of mixed breeding [Blacks & Spaniards]. And, if you look at American Indians or Eskimos, you’ll see they’re actually from Asia and traveled while the lands were one. Then the lands began to drift creating the puzzle pieces we know today.
Now I’ll go back to my old example of “William Wallace”. The Scots were one of the first peoples to see the value of property and fought hard to keep it. Of course it didn’t last, but the point is “invasions”. The Scots gave the Brits a run for the money so the Brits decided – if we can’t control the land, then we’ll breed them out, hence, rape the women so the offspring’s would be half English. Then we have Royalty who went from one extreme to another. At first they wanted to keep the power within themselves, so they had incest breeding [yuk!]. Then the drive for power escalated, so they united kingdoms through marriage, like Britain and France, resulting in interbreeding. This has been going on for centuries and millenniums. In fact I saw a documentary where they found relics of a child they believe to be part Neanderthal and part Homo Erectus [or Homo Sapien]. Again, interbreeding happened million of years ago. When you think about it, aren’t we all “mongrels”? We are evolving into ONE race – the human race. It’s just that our evolution into ONE race is becoming more apparent with interracial people, versus a person whose mother is German and father is Italian. It’s all the same.
If I can take it one step further… again through time.
[uh oh, I’m already chuckling, but here it goes…] You’ve heard that some believe extraterrestrial's visited planet earth throughout time; from the time of the pyramids and stone hedge, to modern crop circles and so on. If they traveled light years through space
[six trillion miles = ~ one light year], who exactly are they? Hypothetically they have a torso, two legs, two arms, a neck, a head, and two eyes. Hmm, so do we. They communicate through telepathy in which some of us are able to do today; there's so much to learn about the brain. One theory of who these extraterrestrial are is "us"

million of years from now, who travel back in time to help us evolve into what we are to become… them

. Now I’m not saying I believe it, but it’s something to think about. Maybe they’re the final evolution of all the mongrels in planet earth.
Sorry pup for not getting political, it’s just that there’s so much ugliness in the world already, why add to it by taking words like mongrel out of context [not you, but the press].
PS- Darwin may have said mixed species, but it's just interbreeding.