When interviewed about my book, often the first question asked is “So what does come after Homo sapiens? I never answer, “Homo nouveau” which is the name I have given to the next human species since it really doesn’t tell anyone anything. What they really want to know is what does this creature look like?
The simple answer is that Homo nouveau will look just like us. Well, what does that mean? Homo sapiens have a lot of different looks. Yes, and so will Homo nouveau. My hypothesis is that the next human species will be the result of an off-target epigenetic mutation secondary to a popular genetic engineering procedure leading to a post-zygotic reproductive barrier. If you haven’t read the book, this sentence may not have much meaning for you. The basic premise is that many Homo nouveau will come into being over a period of decades or longer because they or their parents all underwent some popular germline genetic engineering procedure. That procedure could be anything and I speculated it would be related to attempts to alter a complex genetic characteristic such as aging.
Assuming that procedure is available to anyone in the world, then the collective appearance of all Homo nouveau will have the same variation as Homo sapiens. One will not be able to tell one from the other by appearance, language, culture or any other characteristic…except one. They will only be able to have viable offspring by breeding with another Homo nouveau. Interbreeding with Homo sapiens will not result in viable pregnancies.
Over time, since Homo nouveau will be a metapopulation with a separately evolving gene pool, they will evolve physical and other characteristics that will diverge from Homo sapiens. That will happen both by classical Darwinian natural selection as well as likely further genetic engineering. There is no way to anticipate exactly what those differences will be. Much of that will be determined randomly. At some unpredictable time in the future, they will look and act differently.
How does this scenario regarding the speciation of Homo nouveau from Homo sapiens compare to the speciation of Homo sapiens from our predecessor? There are similarities and differences.
The similarities reflect the fact that in most speciation events the new species looks the same or similar to the previous species at least in outward appearance. With regard to Homo sapiens, we don’t know for sure exactly which human species was our immediate predecessor. It may have been Homo heidelbergensis or some other closely related human species and it almost surely happened in Africa. It was not some sudden event, however. As Sally McBrearty and Alison Brooks point out in their marvelous article, “The Revolution that Wasn’t: A New Interpretation of the Origin of Modern Human Behavior” (Journal of Human Evolution 39 (2000): 453), the transition to modern humans from our predecessor happen over a period of over 200,000 years. In fact, it probably happened in multiple regions of Africa simultaneously during that period.
Similarly, as Robert Foley said in his book Humans Before Humanity: “As we have seen here, human evolution is no blinding flash and no special creation. Man did not make himself, nor woman herself. Both are the product of countless events in the daily lives of the hominids. There is no magic ingredient in human evolution, and no substitute for knowing the details of what happened – where and when and why. Small, insignificant earthquakes in Africa, or particular demographic trends in Europe, are responsible for what happened in evolution. We should not let the uniqueness of our species dupe us into believing that we are the product of special forces. Cosmologists studying the origins of the universe need to think in terms of a big bang. Evolutionary biologists are better off with a bout of hiccups. If we had been privileged enough to observe the origins of our species and our lineage, we would have been struck by one thing –nothing very much happened.”
Let me emphasize: Had we been observers during the period when archaic humans transitioned to modern humans, it is unlikely we would have noticed it. In that regard, that transition is similar to my projected speciation of Homo nouveau.
The differences, however, are dramatic. First, we are going to directly cause the speciation through genetic engineering. Second, it is going happen much more quickly than over a period of 200,000 years. Finally, we, the predecessor species will be cognizant of what is happening.