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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."
...advanced to the point where really stupid people can safely breed with other really stupid people, the predicions of "The Marching Morons" and "Idiocracy" will come to pass.
We just have to feel special, don't we...
As if all of the sudden when you gain intelligence, the rules of evolution change to a new set. Perhaps the term evolution should always be prefaced with a qualifier, such as "biological" or "human" where the qualifier has distinct meaning, and can make it a subset of other qualifiers. It just seems to me that the increase in our intellectual evolution is no different than biological evolution. Not to say we shouldn't put our effort into researching cognitive science, it is a remarkable field. But I think looking at it in this way makes us feel special for no good reason and can muddy the waters more than clear them.
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?
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Companions the creator seeks, not corpses, not herds and believers. Fellow creators the creator seeks -- those who write new values on new tablets. Companions the creator seeks, and fellow harvesters; for everything about him is ripe for the harvest.
Fertility rates are coming down everywhere, even in the developed world, where the exigencies of daily survival still tend to apply some selection pressure on intelligence.
Since H.G. Wells, there has been some speculation that the human species will split into two distinct gene pools (I wouldn;t say "species," since interbreeding remains a possibility). However, if one gene pool should find itself supporting the other, larger pool, the burden would eventually become too great and the two pools would either re-merge or one would become extinct.
"The impossible often has a certain integrity that the merely improbable lacks" - Dirk Gently
I love the internet. A mutant allele of the chemokine receptor CCR5 gene (CCR5-Delta32), which confers resistance to HIV-1 infection, is believed to have originated from a single mutation event in historic times, and rapidly expanded in Caucasian populations, owing to an unknown selective advantage. Among other candidates, the plague bacillus Yersinia pestis was implicated as a potential source of strong selective pressure on European populations during medieval times. Here, we report amplifications of the CCR5-Delta32 DNA sequence from up to 2900-year-old skeletal remains from different burial sites in central Germany and southern Italy. Furthermore, the allele frequency of CCR5-Delta32 in victims of the 14th century plague pandemic in Lubeck/northern Germany was not different from a historic control group. Our findings indicate that this mutation was prevalent already among prehistoric Europeans. The results also argue against the possibility of plague representing a major selective force that caused rapid increase in CCR5-Delta32 gene frequencies within these populations. Linked here
This is a pretty old theory. It's the basis of the 1970's book and TV show "The Ascent of Man" by Jacob Bronowski. His final chapter (as I recall it, it's been years since I read it) says that human evolution accelerated because of "cultural evolution." In other words, Man is the only species that can pass its knowledge to future generations by means of words. This allows each generation to evolve beyond the previous, without having to create everything from scratch. But Bronowski also said that alongside Cultural Evolution, there was also real biological evolution, because people tend to fall in love with people like themselves, and intelligent people marry intelligent people, a form of natural selection for intelligence.
Here's one example of an evolutionary path. Data indicates that sickle-cell anemia may have evolved in order to give resistance to malaria. As a plus side, people with sickle-cell anemia have resistance to a deadly disease, on the downside, people with sickle-cell anemia can experience pain in their joints and death. If our governments got their act together we could either eliminate or severely curtail the presence of malaria-carrying mosquitoes. If such a decrease in malaria occurred, it might lead to a reduction in sickle-cell anemia in the human gene pool. An example of tech (and to one's confoundment, politics) influencing environment and evolution.
It's long been claimed that the development of human culture freed us from evolutionary pressures, by separating us from our prior, "natural" niches. Thus we may be "evolved from monkeys," but that's enough evolution, thank you. We've stopped doing that nasty stuff!
The current Ah ha!, backed up by analysis of genetic clues, is that of course evolution applies to creatures in any niche, and the rapid change of available niches forces relatively rapid evolution. Since a niche largely comprised of human culture will actually often change faster than an "merely natural" one, instead of "saving us" from biological evolution, it forces biological evolution to run faster - with the increased populations our cultures support providing more raw material to work the evolutionary process across.
So our cultures are part of the loop that forces biological evolution - both by defining many of the biases of "sexual selection," and also by defining the niches our fitness is for.
It also, of course, can work backwards: the "least evolved" of us work for their own benefit by trying to revert the culture to prior states, in which they used to have some genetic advantage. This is known as the "conservative" strategy.
"with their freedom lost all virtue lose" - Milton
There has been plenty of writing inquiring whether cesarean section has contributed to evolution. Most think we are too early in the cycle to answer this question since modern c-section. There hasn't been a statistically significant number of c-sections that went well for both mother and child until recently(mothers, in general, exert environmental influence in the long term survival and well being of the child). The logic is that if the mutation that causes our brain to grow really large continues, it hits a natural physical constraint - the size of the birth canal. The head can only be as large as it can be reasonably pass through the female pelvis. Previously difficult pregnancies that resulted in emergency c-sections would mean brain damage for the child and high mortality rate for the mother. Modern c-sections are much more safe and most are even planned. In US around 30% of all births are through c-sections. I don't think I have read a study yet on what that means for modern human development - could all the increase in ADHD, asperger's and other developmental issues be a result? Maybe it hasn't shown up in the Flynn effect because of normalized curve is wider - ie there are more intelligent people but also people who are born with mental issues as a result of the increase in brain size?
too much empathy is a bad thing
witness modern city dwellers who do not breed, but devote massive resources to the pampering of small yapping ratdogs
gene failure right there... for the humans, not the ratdogs
for the ratdogs, it's the genetic jackpot: what started with a virile wolf who decided to follow the humans around for scraps rather than hunt on its own, many moons ago, has now warped into a small retarded spastic defenseless ratdog. and yet it has a survival advantage like no wolf in the history of wolves ever did
but, like any parasite, it mustn't destroy it's host ability to reproduce
conclusion: small yapping ratdogs need to somehow evolve the ability to somehow convince their empathy immobilized hosts to reproduce, and make more empathetically addled humans who dote on small yapping ratdogs
maybe some sort of pheromone, hmmm
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
For now. In just a few generations, humanity will probably be choosing genes for kids as SOP. (Already in the next generation, smart drugs will probably be quite common.)
If we are DNA-based at all in a hundred years. Check e.g. "Mind Children" by Moravec.
All this, like racism, is just history. It won't be relevant soon.
Karma: Excellent (My Karma? I wish...:-( )
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.
I thought you were supposed to separate the colors in M&M? At least, that's what I did as kid.
Sigh... Kids today are so violent. It's amazing that humanity haven't dead ended on the evolution tree yet.
But that's just breeding for disease resistance...Or luck.
No, its not. It takes a lot more than luck to survive for 40 years, and it took a lot more than luck for 4 billion years of evolution and successful reproduction to produce you. Its merely adjusting the human clock which is based on breeding age. Just because you are changing the breeding age does not remove the other traits as selection factors, all the selection factors would remain, and I think also benefit from pushing back the breeding age.
Don't we want to select for things like, intelligence, athletic ability, physical attractiveness? If someone who is hugely intelligent but prone to disease is allowed to die without passing that on, then that's probably a bad decision.
Presumably only the intelligent, athletic, and physically attractive would survive and reproduce at 40. Also, importantly those who are still intelligent, athletic, and attractive at 40 have a better chance of attracting a mate. What percentage of the population is intelligent, athletic, and attractive at age 18? Whats the percentage at 40? At 60?
I started the discussion with "Eugenics works, but is of course worse than the disease."
What is Einstein or Tesla had lived 200 years? What would a longer lifespan do to the crime rate, the economy, war, and practically anything else you can think off?
Anyway, if you wait till after 40 as a woman, you're going to have a much higher risk of birth defects, and that's not anything to be encouraged.
Well thats what happens when you push the limits of human longevity and reproduction. Evolution doesn't work unless someone is prevented from breeding, in this case the mother or child that don't make it.
There are also many social, and economic consequences to instituting a system such as this.
I'm not saying it should be done, I'm just saying it would work.
Libertarian Leaning Political Discussion Forum.
Seventy percent of Chinese teenagers are short sighted. Perhaps more with age. :)
This is caused by pax-6 gene.
So, all electronic interfaces have small text and buttons.
So pax-6 expression becomes an advantage in the west too.
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
A polar bear is a cartesian bear after a coordinate transform.
How well aquainted are you with the facts? Have you ever lived in Africa etc, or is this just TV knowledge?
I lived in Africa for 30 years, mostly in rural or semi-rural areas and I could speak two African languages. I even helped out at mission hospitals a few times. Sure, there are still huge mortalities relative to first world countries, but there have been huge changes. Infant mortality has been reduced significantly and many diseases have been almost wiped out (relative to say 40 years ago). Even small mission hospitals are able to provide obstetric services (caesarian section & premature baby care). 50 years ago those babies would have died (and many of the mothers too). Now they live on to keep their genes going.
From an emotional/sentimental point of view I think it is great that we can be saving human lives, but genetically it is perhaps not the best practice.
I live in a rural sheep farming area. Keeping a flock of sheep is all about improving the genetics. If a ewe has a problem giving birth then the ewe and her lambs are marked for culling (ie not allowed to breed further, but get rendered to meat). This is done because the farmers know that the daughter of a problem ewe is likely to also have the same problems. Culling prevents passing on the gene to the rest of the flock.
At the natural level we are not really any different. When we interfere and artificially keep people alive and allow them to reproduce then we artificially introduce weaker genes to the human gene pool.
I'm not for a second suggesting some sort of forced human selection etc, but just raising the thought that medical technology does have a potential long-term genetic downside.
Engineering is the art of compromise.
As an atheist, let me suggest you something...
Every person I've met encouraging eugenics in the one or other form has himself a genetic flaw which could result in his/her extermination/sterilisation. Having a need for glasses could be a reason, for example. Mild forms of Aspergers (which often is linked to geekdom) could qualify (and - in fact - are currently fought against with Ritalin). Maybe the society just does not like your hair color. Where do you draw the line?
We are all mutants, you know...
Screw the FSM - Real geeks believe in the Invisible Pink Unicorn
I just don't think you fully conceptualize either how large 6 billion really is, or the time spans over which evolution can work. And I think you are idealizing world conditions right now. Plenty of people never breed even if they survive to old age. Without immigration, many countries such as Italy would have negative population growth right now. Plenty of people breed more than others. The short and unattractive don't always meet up, and they don't always get it on when they do. We aren't as much serial monogamists as you seem to think. Do you know about the link between testicle size and promiscuity in the animal kingdom? By body mass, our testicles fall in between bonobos and chimpanzees amongst our closer relatives. Do you know that bonobos are kinky, promiscuous little beasts that are run by dominant lesbians? Even amongst chimps, who are mostly polygamous (where the dominant male gets the chicks) the ladies will get some outside the harem. And genetic surveys of humans show that upwards of 10% of children don't have their mother's husband's genes. Trust me, there is still plenty of wiggle room for evolution to work in.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
Not quite what you're talking about, but look at The Baldwin Effect. It's basically the idea that general learning ability can be selected for as a survival trait - sure seemed to work for us.
You might also be interested in the idea of the 'extended phenotype', a term apparently coined by Richard Dawkins during one of his more useful phases. The extended phenotype considers factors beyond simply the body plan of an organism; for instance beavers' dams are part of the extended phenotype of beavers, and technology is part of the extended phenotype of humans.
.evom ton seod gis eht
It could be that the compassion we show to the old and infirm is just a by-product of the compassion we have for our own kids and even ourselves. In other words, a recognition that this, too, is our lot in time. That compassion, that working together to protect each other, just might improve the survivability of the set of genes that make up the individuals we're talking about. The evolution of compassion and altruism is a very hot topic. I wouldn't dismiss it, or the significance of compassion to our species, so readily.
I don't like it when people see evolution as something that can be measured, or something that only happens genetically, etc. Isn't evolution simply a synonym for "things change, and some things change in a way that sucks for them"? What i mean to say is that yes, we are at a special moment in history, starting to have the power of genetics, and thus the basis of (a part of) biological evolution in reach of having it under our control. But genes are just the means to an end. So is the fashion-du-jour of what is sexually attractive, or what way of thinking is 'better' than others. In a certain way, evolution doesn't even have to be limited to biology (maybe it is by definition, but IMHO shouldn't be), since every physical and chemical reaction also strifes to equilibrium points, in accordance with their environment - just as animals and therefore humans do. Whether this happens because genes change, or because we decide consciously what we want our offspring to be like, is kind of irrelevant, since transhumanism (which i am a big fan of) wouldn't be the end of evolution, but just another form of it. Just as when fishes first started crawling on the land, it just changed some of the rules of the game, but the game is still the same.
Calling it "phenotype" does injustice to the fact that it isn't just an expression of genetic information, but carries information itself. Humans are currently three different parallel lines of communication information generationally: genetic, cultural and technological. We're using technology to transmit cultural information, we use culture to propagate technology, we use both to pass on genetic information. We're about to start modifying that genetic information at will (by means of technology - possibly hampered by culture) while we're passing it on.
Everything bleeds. Into each other.
We're all born with nothing.
If you die in debt, you're ahead.
This merely means that the plebeian of the 3rd millenum cannot measure up to the brilliant greats of the first -- but nobody claimed that you should be able to.
I, for one, have the mental power and the skills of a CIcero. I can comprehen every single thing Archimedes did and I can do things that would have been forever beyond them. If I could meet any one person who lived before 1500, I could teach them a great number of things in their fields of endeavor. And then some more in fields they didn't tinker with.
The reasonably bright college senior today has a better grasp of philosophy than Socrates, a better grasp of mathematics than Pythagoras, a better political understanding than Seneca. Because we're standing not only on their shoulders, but the shoulders of those who stood on the shoulders of those who stood on their shoulders. We do not have to spend our time re-re-re-inventing whole conceptual areas from scratch because we get what worked in the past handed to us. We don't have to invent numbers and mathematical symbols -- we simply use them as-is. We do not have to invent physical concepts, social classifications, anthropological superstructures.
We take all their work and filter it through history and can come to very quick and efficient conclusions what works and what doesn't. Dozens of tomes theological writing of Newton's -- and what remains of his life's work are four equations an a mechanism he co-discovered with Leibnitz. I can take those four equations and mix them with one that Kepler found after nine years of dead ends in the study of Mars and convey the whole thing to a bright college freshman in two hours.
The stupid today are no brighter than the stupid ever were. But the bright minds of our time outshine anything that has ever happened before.
We're all born with nothing.
If you die in debt, you're ahead.
No, you misunderstand my point. Probably I didn't explain it well enough.
I'm _not_ saying that altruism and arts are useless. God forbid.
I'm saying only that evolution was most often a matter of predator and prey trying to out-evolve each other. In this case, the humans were both predator and prey. That's really all I'm saying.
Maybe altruism played some role in being able to survive. Could be. Sticking together certainly did. But that's already a bit of a tangent. And I never intended to say that altruism was worthless, or anything. (Though I would bet that a lot of altruistic people got themselves out of the gene pool anyway.)
I'm just saying that humans _did_ kill other humans, regularly. There was much the same eco-system as between foxes and rabbits, or lions and gazelles, but this time with humans in both roles. And that seems to me like plenty of natural selection.
But I never meant that only the predators evolved. There's just as much pressure on the prey to evolve.
What I'm saying is that between the two factors
A) evolutionary pressure based on survival or death (as in, literally, if you don't think fast, someone will literally lop off your head and put it on a pike), and
B) the evolutionary pressure of picking the prettiest wives,
Dunno, the former seems to me like a much stronger pressure. In fact, for most of human history, the latter was probably rather weak.
Even if you look at selecting the guys or gals who look healthy, I'm betting there were more short time pressures to actually _be_ healthy. Looking healthy might have given you a little better chance of finding a good husband, but actually _being_ healthy meant you actually survived the next famine or epidemic. Not looking healthy might have had an effect in the decimals, but not _being_ healthy actually killed.
A polar bear is a cartesian bear after a coordinate transform.
In my next incarnation, I want six digits on both hands, a tail, and four nipples. So just grin and bear it, people!
You may be more accurate than you think, and may even alter the DNA expression during this lifetime according to Bruce Lipton, which show some scientific results behind his assertion:
That our feelings and belief-systems actually alter how our DNA is decoded all the time!
Part 1: http://video.google.com/videoplay?docid=-8506668136396723343
Part 2: http://video.google.com/videoplay?docid=-6568107389365915765
http://www.debunkingskeptics.com/
There are people who are immune to HIV - they comprise approximately 1% of the general population - researchers have studied the ancestory of these people and concluded that these genes spread during the plague in the middle ages - since the plage attacks the immune system in a similiar way as HIV. Note you must have two copies of the gene to be completely resistant if you have only one you still die but it takes longer. No doubt the reason why everyone does not have two copies of this gene is because there is a cost associated with having it, such as incresed susceptibility to some other disease....