Speculation Regarding Future Human Speciation, Part II


[My first post on this subject appeared here.]

In the future, the human race, homo sapiens, will do what all living organisms do when circumstances change, as they always do, sooner or later. We will adapt, migrate, and/or die. Since this is a post about speciation, I’m mentally setting that part of my brain which worries about extinction happening relatively soon to “hopeful,” for the duration of writing this post.

For speciation to happen, two things must happen first: reproductive isolation, and the passage of a lot of time. Migration (to off-earth colonies, for example) can produce reproductive isolation, but so can other things. As for adaptation, this is done in many ways by our species, consciously, as well as unconsciously. Evolution is always happening, but it is the slowest of all human adaptive processes. It is estimated that it has taken us (and everything else) 3.85 billion years to evolve, after all, and that’s roughly the most recent third of the time since the Big Bang.

Extra-terrestrial colonies would definitely be a huge “push” toward speciation, especially colonies with low gravity, relative to that experienced by other people. As well-described in Robert Heinlein’s novel The Moon Is a Harsh Mistress, return to a high-gravity environment, after many years in a low-gravity environment, would carry significant health effects, with serious risks of sever complications, up to, and including, death. If we ever establish colonies outside the solar system, this isolation will become even more extreme, simply due to the enormous distances and travel-times involved.

However, we will speciate, as will all other species, if we stay alive long enough, even if no more of us leave low-Earth orbit.

In my previous post on this subject, I speculated about the emergence of fully-speciated homo lunaris,  homo literaticus, homo illiteraticus, artificially-genetically-modified humans (whom I did not name then, but homo techogeneticus would do nicely), and homo cyberneticus. An increase in the number of infertile offspring between two groups, combined with a falling birthrate between them, persisting over millennia, would be an early warning signal that speciation might be happening — that’s how long this evolutionary process takes.

Given enough time, and increased reproductive isolation from non-“Aspies,” another group which could speciate is the population with Asperger’s, to form homo aspergerus, primarily because of the difficulties each group of people have communicating with the other group. However, I’ve written several posts already which seek to help Aspies and non-Aspies understand, and bridge, the communication-gap. What’s going on here? Simple: evolution is simply a process which happens. It has no ethics. It is neither good nor evil. More to the point, just because I can discern a possible future does not mean I want that possibility to become real.

In what other ways could speciation happen? A widenining gap between the rich and poor certainly seems possible as a “push” towards speciation, at least currently, which could create homo plutocraticus and homo povertus. It is easily possible to imagine this happening along with the emergence of homo cyberneticus.

Another interesting possibility would occur if humanity survived in the North and Southern hemispheres, near the poles, but extreme global warming made tropical regions uninhabitable, and the equator untraversable, or at least very rarely crossed. In this case, it is hard to imagine what direction the changes would take, for they could go in many directions. Names for such Northern and Southern humans could be homo borealis and homo australis, from our point of view. In theirs, of course, as in many of these scenarios, the likely terms each group will use for the other will translate, roughly, as “us” and “them,” unless they somehow manage to shed the primate characteristic of forming rival groups, one which long predates humanity.

How could the maximum number of new species emerge in the least time possible?  This is known: a mass extinction would be needed, one which leaves a small (but large enough) percentage of humanity alive, and fertile. This would open numerous ecological niches which we, and other extant species, would rapidly fill, by rapid speciation, into an amazing variety of forms. Again, this simply happens — that does not mean it is to be desired, and I am certainly not hoping for it to happen soon. I simply realize that it has happened before, and we have no reason to think it will not happen again.

Speculation Regarding Future Human Speciation, Part I


If human beings survive long enough, the unstoppable process of evolution will cause us to speciate again, as has happened many times before. Many millenia from now, there could be several different species of human being, with any hybrids which exist being infertile. What follows is speculation regarding some possible details of this entire process.

Speciation happens because of genetic drift, aided by reproductive isolation, which can happen in several different ways. For example, suppose humans establish extraterrestrial colonies. This would produce reproductive isolation by simple geographical isolation. The first such colony will likely be on the moon, and, once the colonists grow accustomed to such weak gravity, returning to earth would be extremely dangerous. Just imagine weighing six times as much as you are used to weighing, suddenly — that’s just what it would be like for a lunar colonist to return to earth. This danger would be even more severe for those actually born on the moon.

If speciation happened in this way, those back on earth would probably still be called homo sapiens, with a new name given to the off-world humans, such as homo lunaris for “moon people.” As colonization moves outward, to Mars, Jovian moons, etc., other new species could form in the same way, each with an astronomically-derived species-name, and characteristics shaped by their new environment.

However, back to earth. What happens here, while these new types of people are forming off-world? Well, no species lasts forever. Either homo sapiens are the last people on earth — human extinction — or we have one or more successor species here, eventually.

Reproductive isolation does not require geographical isolation. Another pathway to reproductive isolation involves differences in behavior. One example is the activity of reading. You’re reading this right now, which means that you not only can read, but actually choose to do so. Do all people have this ability, or make this choice? Certainly not. What’s more, many non-readers dislike readers (otherwise, the insult “bookworm” would not exist), and, often, the feeling is mutual. Obviously, reproduction is more likely to happen between those who like each other, rather than between those who don’t.

This particular split, based on literacy, has not yet produced new species. Why not? Simple:  there hasn’t been enough time (yet). Writing has only existed for ~5,000 years, and education has been widespread for a far shorter time. Given many more thousand years, though, two successor species, homo literaticus and homo illiteraticus, could well emerge.

Advances in medicine and computer science, combined with continuing inequality in wealth and income, could also produce variant humans another way:  deliberate modification (for those who can afford it). Such modification could happen in multiple ways:  manipulation of the human genome, for example, or the creation of cyborgs with organic brains, and silicon-based computers, fully interconnected (homo cyberneticus, perhaps). Such projects would be rife with controversy and ethical dilemmas, of course, but that, by itself, will not stop experimentation, any more than ethical concerns prevented humans from constructing the thousands of nuclear warheads we still have (and have, for the most part, avoided using — so far). The fact that a change would cause a lot of problems is not, by itself, sufficient to prevent that change from happening.

There are many other possibilities as well. One thing is certain:  we won’t simply stay like we are forever.