Did you know that labrador retrievers and humans have some things in common?
There are black, brown(chocolate), yellow, and white labs. Even though they look different, they're all basically the same animal.
Same as people
Do you know what happens if you were to only let labs hangout and reproduce with other labs that are the same color?
They'd probably end up a little close eye'd, run a little crooked, and have shitty health problems.
Huh, same as people.
Did you know that if you were to let those labs just hang together and interbreed that they would be healthier, smarter and better able to adapt to new situations?
Did you know that's how people work also?
A big difference is that labs don't care what color the others labs fur is.
Here's another thought, what breed of human are you?