How Will We Know?

If you choose to be even moderately optimistic about the future of humanity, it's pretty much a given that at some point we'll end up in space, and we'll colonize all sorts of places, some very like parts of Earth, others... not. It's also pretty likely that sooner or later we'll be able to perform gene modifications, inheritable and otherwise.

Which inevitably brings up the question, will we still be human? And with it, if we stop being human at some point, how will we know?

There's any number of stories in that, ranging from near future SF all the way out to possible futures so bizarre they might as well be fantasy. The question of whether we'll end up as a whole lot of related species is its own subset of these.

At last year's WorldCon in Denver, I wound up in a fascinating discussion with an evolutionary biologist and several other scientists of varying flavors. I don't remember how we got to the question of speciation, but it seems the jury is still out on the question of whether you've got a separate species when two groups can breed but don't (because of geographical or morphological issues), when they can breed but the offspring usually won't be fertile (ligers and mules - which actually can be fertile but usually aren't), or when they can't breed at all. The obvious example here would be dogs and wolves - which are usually considered separate species but can produce fertile offspring - and of course the various breeds of dog, which at some extremes would have a lot of difficulty breeding. While a peke with a stepladder could mate with a great dane, it doesn't happen often, and for obvious reasons it's a unidirectional mating unless some really perverse person wanted to do a test tube fertilization with great dane sperm and peke ova then implant in a female great dane (because there's no way on earth a peke is going to carry those puppies to term).

So... when do we humans speciate, and what will happen then? If we engineer people to live comfortably in null-gravity, are they and their children still human? And of course, where does our old friend evolution fit into all this?

People tend to forget that evolution is still, well, evolving as we speak. Pale skin is an adaptation to living in climates where there isn't that much sun. Lactose intolerance is the human norm - only the cultures where milk is a major food source have a significant number of people who can drink it as adults. People who have been living in cities for generations have, on the whole, brain structures optimized for multi-tasking by comparison with people who have been living in small rural communities (don't ask me for references. This is the stainless steel lint trap in action. I remember weird shit with no idea how it got there).

Here's the thought experiment. Let's say three more or less uniform groups set off to colonize some newly discovered planets. We won't go into how they get there. Group A finds themselves a tropical paradise - big oceans, most of the land masses are in temperate to tropical zones - with plenty of edible plants and animals. Group B's new home has pretty distinct seasons, but adapts very well to Western style agriculture, and also has some large predators. Group C gets the booby prize - they find themselves in a hostile climate where they need to make the most of every drop of water, defend against filthy weather, and protect themselves against a range of predators, poisonous critters, and just plain nasty stuff.

Fast forward a few thousand years, assuming that all three groups have been pretty much isolated and managing without outside intervention, and what do you think you'll find?

Here's my guess. Group C will probably be either dead, or a collection of geniuses, because in that environment if you're not smart enough to do the right things and forward thinking enough to do them before you need it, you're dead. They've probably made a bunch of technological advances just to cope with the environment. Group B will be about... well, average. Seasonal variation requires a certain amount of foresight and intelligence, but not nearly as much as a situation that seems designed to kill you if you slip up. Group A, with their tropical paradise? With nothing to kill the not so bright, and a nice easy food supply, they'll probably have changed least, and be, as a group, the least intelligent. Meaning if you picked a random person from A, B, and C, chances are the person from C would be smartest (and probably kind of paranoid), the person from B middling, and the person from A not so bright and probably pretty relaxed and easygoing.

What do you think will happen? And will all three still be human?