Recent Human Evolution May Have Been Driven By Self-Selection

Slur writes "The New York Times reports an insightful theory of Human evolution that gives credit for our accelerated evolution to the evolving brain. By virtue of our aesthetic and utilitarian preferences we ourselves have been responsible for molding the present human form and consciousness. Applied to other species we call it 'artificial selection,' but the new theory implies we did it all quite naturally, unconsciously, and that the exponential evolutionary acceleration we have achieved as a species in recent time is just what you'd expect. It also suggests that the current lull in our physical evolution is by 'choice' as well."

Comments

Who needs evolution with technology

[Anonymous Coward]

It doesn't matter if we evolve, because we change the environment around us as opposed to adapting to it. Therefore evolution has been irrelevant as a factor of survival since humans learned to use tools.

Re:Who needs evolution with technology

[Toonol]

It's not that one-sided. For example, we've invented cars, and now we drive fast. People with a poor ability to process visual information quickly, project trajectories, and convert that to a decision to turn/brake are going to be selected against. That's just an innate consequence of having developing an automobile.

We are changed our tools, while our tools are changing us. Granted, our tools are changing at a much faster rate...

i was just arguing with some guy

[circletimessquare]

who comes from that classic heartless eugenics-oriented pov that we as a species are getting physically unfit as we allow the autistic, the downs symdrome, the epileptic, etc., to survive and breed. in classic trollish fashion, he insisted the cavemen had it right when they just left the old, infirm, etc. to die outside in the snow

my response was to question the supremacy of physical fitness. for example, the rise of humans in larger groups, cities, drives the emphasis on new genes: human empathy, for example, being a highly desirable survival advantage in large groups. and the less physically fit in large groups can still contribute to the survival of the group. such that a well-organized group of less physically fit humans can outcompete very fit physical specimens that unfortunately aren't as well wired for human empathy, and therefore are out there, loners, failng to coordinate with othwer humans for the successful passing on of their genes. the rise of cities changing the emphasis onto new genes for survival

which, ironically, given his utter lack of empathy for the less physically fit, put him on the lower end of the "fit" gene pool, where "fit" now means more empathetic, not bigger biceps

perhaps we should leave him out in the snow i wondered? ;-)

Re:i was just arguing with some guy

[KDR_11k]

he insisted the cavemen had it right when they just left the old, infirm, etc. to die outside in the snow

AFAIK even very early cavemen didn't do that, there's evidence of cavemen taking care of the crippled and elderly.

Re:i was just arguing with some guy

[Raffaello]

This is an oversimplified view of how evolution works. In fact, it's so oversimplified as to be grossly misleading.

Evolution works by *differential* reproductive success. This does not require in any way that we leave the "unfit" out in the snow. Their own genetic disadvantages will see to it that they simply leave fewer offspring.

By intervening directly (the "leave them out in the snow" school) you run the very significant risk that you mistakenly identify as "unfit" individuals whose genomes contain significant survival advantages that would otherwise be passed on in the gene pool.

IOW, not being omniscient, people are likely to identify as "unfit" individuals who they simply don't like, feel threatened by, etc., and prevent from reproducing people who are, in fact, carriers of genes with significant survival value.

It's called "natural selection" for a reason: the inevitable expression of each individual's genome will of necessity result in some individuals leaving more offspring than others. These individuals are, *by definition* the fittest. No need to intervene - it's already taken care of.

Note that in artificial selection, breeders can only select for heritable traits that they observe. In the process they often end up with breeds that carry significant deleterious traits because the breeders were not aware that they were inadvertently selecting for these as well.

It all comes down to humility about our lack of omniscience. Anything short of a complete understanding of all the complexity of the human genome, epigenetics, and how these interact with various past, present and yes, even future environments, will lead to the unintended, but potentially disastrous reduction of variation and loss of genes of significant fitness.

The system (natural selection) works well precisely because there is nothing driving it except the objective reality of navigating the myriad vagaries of life successfully to the goal (from evolution's standpoint) of reproducing. Let's not pretend that we understand all of it fully and interfere with it.

Re:i was just arguing with some guy

[2nd Post!]

What is the benefit to our species as a whole to create genetically wrong humans?

Excuse me?

How about the geniuses with perfectly sound minds but unsound bodies? Like Stephen Hawking?

Are you saying the only value humans have is their ability to survive independently of each other? That children who cannot hunt down a buffalo without the help of a parent, or even a peer, is useless? Yet what is cooperation to achieve things greater than an individual (the space shuttle, the pyramids, the aqueducts of Rome, raising a single child) except "depending on society for the rest of their life"?

Perfectly FIT people depend on society their whole lives! Can you generate your own electricity, recycle your own trash, smelt your own steel, craft your own furniture, etc?

So even genetically wrong people can offer things, such as their minds, their voices, their arts, etc, to humanity. On top of that, their survival broadens our genepool; what if the AIDs resistance virus lies in a mildly autistic child? Or the resistance to the next bird flu pandemic lies in a mildly retarded child?

Medical science kills natural selection

[EmbeddedJanitor]

Natural selection tries to weed out a huge % of the population, but medical science overrides it.

Nature determines that weak and premature infants should die, yet they are kept alive and become adults. Nature determines that some adults should not be breeding, yet fertility drugs override this. Nature determines that various people should die by heart failure etc, but drugs keep them alive.

Sure, these are all good from the emotional point of view of keeping people alive and making childless couples happy etc, but does it really help the human gene pool? Perhaps Mother Nature had a good reason to kill off a weak child or prevent that infertile couple from breeding. The long term impacts can only be known in a few generations.

Survival of the Fittest

[Anonymous Coward]

*Taken from the Best of Craig'slist*

Whenever I get a package of plain M&Ms, I make it my duty to continue the strength and robustness of the candy as a species. To this end, I hold M&M duels.

Taking two candies between my thumb and forefinger, I apply pressure, squeezing them together until one of them cracks and splinters. That is the "loser," and I eat the inferior one immediately. The winner gets to go another round.

I have found that, in general, the brown and red M&Ms are tougher, and the newer blue ones are genetically inferior. I have hypothesized that the blue M&Ms as a race cannot survive long in the intense theater of competition that is the modern candy and snack-food world.

Occasionally I will get a mutation, a candy that is misshapen, or pointier, or flatter than the rest. Almost invariably this proves to be a weakness, but on very rare occasions it gives the candy extra strength. In this way, the species continues to adapt to its environment.

When I reach the end of the pack, I am left with one M&M, the strongest of the herd. Since it would make no sense to eat this one as well, I pack it neatly in an envelope and send it to M&M Mars, A Division of Mars, Inc., Hackettstown, NJ 17840-1503 U.S.A., along with a 3x5 card reading, "Please use this M&M for breeding purposes."

This week they wrote back to thank me, and sent me a coupon for a free 1/2 pound bag of plain M&Ms. I consider this "grant money." I have set aside the weekend for a grand tournament. From a field of hundreds, we will discover the True Champion.

There can be only one.

Probably that's how it REALLY worked

[Moraelin]

Well, that's insightful, and probably how that evolution _really_ worked.

See, selection based on beauty, niceness, etc, are shiny-happy feel-good theories. They make us feel better about us as a species.

They also utterly fail to explain stuff like the ultra-fast evolution of, say, intelligence related alleles.

Now let's think about it for a bit. What's one situation which drives evolution like _hell_? What drove the early evolution of hominids? Having to survive in the face of a nasty predator. That's one _hell_ of an evolutionary pressure.

The early hominids, for example, faced the pressure of having to move out of the trees and compete with nasty carnivores for food. It was a monkey (ok, ape) too unfit to hunt (as late as the Neanderthals, they still couldn't do ballistics: Neanderthals were survival-spec melee hunters;), so it had to steal the food some carnivore had hunted. And it was even less fit to fight tigers barehanded. That's what drove the fast evolution of the brain. Stealth and cunning were the only things that worked.

Now move to the last 20,000 years or so, and humans faced an even nastier predator: other humans.

The history of mankind is, sadly, one of constant warfare, atrocities, etc. Tribes raided each other constantly, and then states fought each other like crazy. And let's remember that this was:

A) millenia before the Geneva convention. If you couldn't take a fortress, it was considered perfectly acceptable to kill or enslave the peasants instead.

B) millenia before logistics. As a peasant in those times, you'd get looted by both the enemy (whole campaigns got slowed down by waiting for the villages in their path to harvest the grain, so the army can loot it) and your own side (as levies.)

So, yeah, humans selected themselves all right. At spear point. Being able to, say, hide and hide your harvest when the next raid came, was already a hell of an evolutionary advantage.

Also let's remember that mortality was disproportionately higher among the lower classes until very very recently. As in, until 2 centuries ago or so. Famine, plagues, war atrocities, etc, took their toll starting from the bottom.

Even if you look at the renaissance era, let's just say we're almost all the descendants of the rich folks back then. The poor mostly died out over enough generations. Or IIRC in China they actually did some study and IIRC some 80% of a province's population carried the genes of one imperial family. That's how disproportionate a survival advantage that was.

So that's your other natural selection factor: those who figured out some way or another to claw their way up the social pyramid, had more chances to pass their genes on.

Some did that by just being smart and hard working. Learning enough of the alphabet would automatically qualify one for a scribe job in a lot of places, from ancient Egypt to China. That already made it a lot less likely that they'll starve during the next famine, plus ensured that they can afford to educate their children too.

Some did it by a lot less nice means.

But at any rate, that's another case of humans selecting themselves.

Etc.

Basically, yes, the ones who survived were the ones who went "And I pick... me!" And proceeded to gain some kind of advantage over the others.

Not a nice thought, but history or humanity weren't nice until the 20'th century. Stuff that we all now get horrified about, when we read about the Third Reich or Stalin, were the stuff human civilization was built upon.

So, yeah, let's instead believe bogus shiny-happy fairy-tales where surely the biggest advantage was being sexy. Heh.

Here's another not-nice thought: mortality among women was disproportionately higher than mortality among men. In the Old Kingdom period, for example, the peak of the mortality gauss curve was in the 20's for women, and in the 30's for men. (Of course, again, the rich tended to live longer.) And even primitive tribes raided each other to s

Re:Probably that's how it REALLY worked

[Moraelin]

Uh, what? Mortality is still disproportionately higher in the lower classes. Everywhere on the globe. And that shows not the slightest sign of changing. As a matter of fact I'd be willing to define "classes" along the lines of life expectancy. How else would you do that? Even the lowest hobo can own a DVD player these days. But he can't afford health insurance...

Ah, right, the USA. In Europe everyone gets healthcare, so sometimes I forget that somewhere an advanced society would leave its less fortunate members just die, out of no other reason than greed. Thanks for the correction.

Absolutely nothing whatsoever has changed since the 20th century. The same atrocities are committed right this moment by the same power-hungry tyrants all over the planet for the same reasons.

A) Not on the same scale, buddy. And,

If you look some 2000-3000 years back, going and enslaving your neighbours and treating them like in the nazi slave-labour camps was a lot more common. Some greek city states had slaves as a third of their population.

And while again we remember the nicer parts -- e.g., the clerk or home servant slaves that were freed later by the rich Romans in Rome itself -- the same Roman society used slaves elsewhere as just a long death sentence. The cost of keeping buying new slaves to replace the dead ones, was an integral part of the cost of business for, say, mines. Or the same rich Romans let slaves starve in Sicily so they could export more grain to Rome. There was at least one slave revolt motivated literally by hunger.

So basically wake me up when you have 100,000,000 people in Guantanamo. That's when you'll have the same extent of the problem.

B) Now at least the common people tend to be horrified about it. In times past they actually were part of the problem. The very fact that you seem pissed off and disillusioned about it, is actually a sign of how much we progressed.

If you look as little as, say, 1000 years back in time, the medieval communes (towns whose citizens swore to stand together for their rights against the noble of the land) found it perfectly ok that, when they were wronged grievously by a noble, they'd go kill the noble's peasants. Or burn his crops so, again, then some peasants would starve.

We're not talking about power hungry tyrants. We're talking about ordinary citizens who found it perfectly normal to go kill some peasants to get their point across.

Or if you look farther back in time, you see such examples as Sparta. A relatively small city held a much larger population of hellots in line by sheer terror. Kids' graduation to adult consisted of being sent to terrorize and kill a few hellots for sport and training.

Basically, nowadays it may be the sport of kings, but back then it was a mass sport. That's already some progress.