BBC News has a pretty cool article on some research published in the American Journal of Human Genetics. The claim is that there was an early split between two populations of Homo sapiens early on, and the two populations persisted in isolation for about 100,000 years. Apparently this wasn’t long enough to achieve reproductive incompatibility, because the populations later intermingled, and we’re left with a single species.
This kind of research always kicks off my imagination. What if speciation had occurred between those two African populations? What if they each began the slow march across the world? What if today, we had two separate, reproductively incompatible populations of sentient animals?
According to our modern sensibilities, there is really only one kind of human animal, and we are all essentially the same to a reasonable approximation. A human being from any part of the world can travel to any other part, and barring any cultural conflict, can learn the language of the people, pick up the customs, perhaps even start a family and produce fertile offspring. Our entire concept of ourselves revolves around our notion that there is only one kind of sentient animal on Earth.
What if there were two? What if there were an entire species whose language was forever impenetrable to us no matter how we tried to learn it, because of differences in brain structure? How would we interact with animals like that? Would we consider them beneath us? Would they consider us beneath them?
I don’t know. I could spin out a dozen more questions on this topic, but very few answers. The history of human evolution is a fascinating line of research.