The process is still going on. Another meteor could hit us wipe out a bunch of species or maybe a solar storm will wipe out communications and other electronics and cause chaos at a time when global warming is creating mass migrations of people and you have the mixture for another bottleneck, if not extinction of humans only while other species survive. There is a lot of randomness that occurs but the process keeps making even more species and we now have over 5-8 million on this planet.
What sparks this "randomness"? I understand that questions that begin with a "why" are usually sometimes hard to answer, but i just dont understand why you or me did not end up as a H. rudolfensis or a paranthropus robustus? What caused you and me to be us and not them?
Neanderthal didn't all die off, some remnants remain in today's humans. The evidence is that we interbred to some extent. Maybe language was the deciding factor. We might have been smarter or able to communicate better. Maybe the glaciation helped, our ancestors made it to the southern tip of Africa. I think there is a mystery there that still might get solved with new information. Asking the question is the first step, you are thinking about things that we would like to find out. I love it.
