@RedDeerGuy1 “Could this happen to humans? Where one race can’t reproduce with another?”
You mean race as in like white, black, Asian, etc? No, not really. Despite our outward differences in physical appearance modern humans (Homo sapiens) are extremely genetically homogeneous. Much more so than most other species, even other primates. There’s less genetic difference between the palest white man and the darkest black man than there is between two unrelated chimpanzees at the zoo.
Now it could be that in time some other new species of human arises. We’re certainly not the only species of humans to have existed (Homo erectus, Homo habilis, Homo floresiensis, Homo neanderthalensis are some others), we’re just the last ones standing. If new species of humans do develop we may or may not be able to interbreed with them. It’s unlikely that we could have interbreed with, say, Homo erectus (even if hadn’t existed nearly 2,000,000 years apart), but we do know that we were close enough genetically to breed with Homo neanderthalensis*. In fact there’s strong genetic evidence in modern humans, particularly in humans of European and west Asian ancestry, that humans did interbreed with neanderthals soon after we began the migrations out of Africa.
*Unlike other ancestral human species, Homo neanderthalensis existed recently enough (within the last 40,000 years) that we’ve found a huge amount of their remains and the remains are recent enough to still extract testable DNA from. From what we’re found we and neanderthals are 99.7% genetically identical.