Humans Evolving Faster Than Ever

Kwyj1b0 writes "In a massive study on genetic variation among humans, researchers found that most changes have occurred in the last 200 generations, too fast for natural selection to catch up. Recent papers show that rare genetic variations have a more drastic effect than previously believed. Another result shows that 'we carry a much larger load of deleterious variants' (as well as positive variants) than our ancestors 200 generations ago."

Comments

This this not evolution

[Ubi_NL]

Acquisition of mutations is not evolution. Evolution is the combination of variations AND selection of those traits that increase fitness. The fact that we only acquire more genetic mutations means that selectionhas gone down and evolution with it. The simple explanation is that healt care enabled us to cheat on selection.

Re:This this not evolution

[Ubi_NL]

According to your definition any genetic alteration is evolution (indluding being exposed to gamma sources). But then you bring genetic drift as an example, which is strange as genetic drift is not an increase in variation, but a SELECTION of a specific allele within a pool, resulting in increased frequency.

Re:This this not evolution

[Fallingcow]

What does "help" mean, in an evolutionary context?

Seems to me that culture is just another factor to which an organism may, over generations, adapt.

Re:This this not evolution

[Ubi_NL]

But even if you define genetic drift as change in variation due to random sampling, there STILL is selection, just not a biased selection. You refer to bottle-neck populations such as pioneers or disaster survivors. That is however not what tfa is about.

If you wish to continue this discussion stop posting as ac, as i will no longer read these posts

Re:This this not evolution

[Arancaytar]

Wrong.

Humans are still reproducing, surviving and dying. Traits are still selected. They're just different traits than the ones that would have been selected if humanity were still living in caves. The fitness function has been loosened, and the net is cast wider now - instead of mutations having to benefit (or not adversely affect) the immediate survival of the individual, there is more room for variety.

A species with a secured infrastructure can afford to gamble on outliers, who would not have survived prior to modern technology. Those gambles can pay off big-time. The absence of an outdated pre-civilization fitness function killing everyone with motor paralysis is what allows our species to benefit from a genius with motor paralysis.

Re:This this not evolution

[Mindcontrolled]

And this, good Sir, should end all the "idiocracy" bullshit. It won't, but it should. I wouldn't necessarily say that the fitness function has been loosened, though - only if you look at the physical aspects of it. Social aspects, sexual selection etc. are probably getting more important, the more the physical aspects are getting lost.

Re:This this not evolution

[Hognoxious]

Evolution can occur on things that aren't coded in DNA. Software, for example.

Dawkins, memes. Does that ring a bell?

Re:This this not evolution

[Qbertino]

What health care was there 200 generations ago?

Pretty good healthcare in some parts of the world. Arabia and parts of the Byzantine Era, for instance, were a high culture more than a thousand years ago with complete health care coverage and other public services. Including stuff you'd have considered high-tech right up to magical in other parts of the world. Water clocks, aquaeducts, mechanical devices, sophisticated smithery and metal working, a school system, superiour math, accounting and efficiency measurement techniques, etc. As for the public healthcare, there are written acounts of people being thrown out of hospitals because they were still enjoying the pampering even though they were well again.

Which, on a sidenote, goes to show how things go down the drain once religious fanatics take over.

Re:This this not evolution

[NReitzel]

No, it's not evolution in the way that believers in a slow random process like to picture it.

This process is called adaptive radiation. Humans have moved into a very large feeding niche, and as a result our population and our genetic diversity has expanded hugely. Hygiene, agriculture, medical intervention, technology, and social institutions have hugely expanded the availability of places that people can survive. In an entirely natural and very old process, we have expanded our population into those places. There are more of us than there are locusts.

The second half of the cycle is the selection part. In the previous century, wars and local famine have played a part in this not so nice aspect of the evolutionary mill. In centuries before that, famine and plague were part of the selection process. In current times, some of the selection pressures applied to isolated parts of humanity include famine, flooding, ability to avoid being a gang member, and facile birth control. Note carefully that the term "isolated" used to refer only to geographic isolation. These days, more important is political isolation. Consider the Democratic People's Republic of Korea, for instance.

As much as some of us would like to think so, we as a species are not specially selected by supernatural powers to be immune from the evolutionary process. It goes on every day and shapes us. The cycle of adaptive radiation includes expanding into a new niche (now, the whole world), and then failure of large chunks of that population when something goes wrong. A recent instance would be the European plagues that took out 60% of the population. The descendants of that evolutionary moment are a little more resistant to Yersinia pestis, in a super-bug meets slightly better people scenario.

Re:This this not evolution

[tmosley]

That was ten generations ago, not 200. Westerners tend to have a very narrow view of history that assumes that the way things were in the dark ages is the way they were in all of pre-history. Couldn't be further from the truth. The truth is that the ancients had many techniques that have only been recently rediscovered, and we didn't actually surpass them until the late 1800's or early 1900's. I would rather be treated by a doctor from ancient Egypt than one from America circa 1820.

Re:This this not evolution

[RabidReindeer]

I should add that selection based on culture (love, pre-arranged weddings etc) rather than fitness also does not help evolution.

Your definition of "fitness" is not the Darwinian definition. It sounds, in fact, more like the pseudo-Darwinian conceit that "fitness" means the ability to kill or resist being killed. When Darwin said "survival", he didn't mean "last person on the island", he meant that the species in question had found a niche where its population would be stable.

Survivability comes in many forms. Some, like tigers are primarily solitary. Some, like herd animals, depend on the group. We have ample evidence these days that in many cases, survivability (in the Darwinian sense), can come even from relatives who never directly contribute DNA to the continuation of the species.

Love as a primarily positive evolutionary trait can be debated, although certainly being unlovable isn't going to afford many non-violent ways to swim in the gene pool. Pre-arranged weddings, on the other hand, can make the difference between a tribe being exterminated or being able to ally itself with other tribes. Systems of laws and mores can ensure that the unlovable whose sole means of propagation is rape will be taken out of circulation relatively quickly.

Social structures as evolutionary forces are not unique to the human race. But they are a powerful contributor. If we went strictly on kill or be killed based on physical fitness, we probably wouldn't have produced a Stephen Hawking.

Re:This this not evolution

[sackbut]

Well, that would not be necessary, Mr. President. It could easily be accomplished with a computer. And a computer could be set and programmed to accept factors from youth, health, sexual fertility, intelligence, and a cross-section of necessary skills. Of course, it would be absolutely vital that our top government and military men be included to foster and impart the required principles of leadership and tradition. Naturally, they would breed prodigiously, eh? There would be much time, and little to do. Ha, ha.

"Now, wouldn't that necessitate the abandonment of the so-called monogamous sexual relationship, I mean, as far as men were concerned? Regrettably, yes. But it is, you know, a sacrifice required for the future of the human race. I hasten to add that since each man will be required to do prodigious... service along these lines, the women will have to be selected for their sexual characteristics which will have to be of a highly stimulating nature."

Re:This this not evolution

[anon mouse-cow-aard]

I call B.S. on that definition. The probability of random mutations accumulating in a population to the point of creating a significant change in allele frequencies without a selective force of some kind approaches 0. Sure, random mutations occur, but they can just as easily occur in the opposite direction barring some sort of "slope" to genetic drift... If there is such a slope, then it is a selective force, though perhaps not classic natural selection. Evolution does indeed require a selective force, which traditionally has been natural selection. If you are going to say there are other selective forces, that's fine, but pure generation of mutations (genetic drift) without selection will not bring about a statistically important number of significant changes in frequency, and thus is not evolution. It is just mutational/evolutionary noise.

Re:It's "Survival of the Fit-enough"...

[wvmarle]

All those babies surviving is something of the last five, maybe ten generations at most. And that's in the Western world. TFA is talking about 200 generations.

Re:It's "Survival of the Fit-enough"...

[Anonymous Coward]

Actually, this is how evolution works, so "Survival of the Fittest" is still applicable. If the current environment allows those individuals to reproduce and pass on those traits, they are the most fit. We will be a bunch of fat-ass couch potatoes eating chips watching CSI-dancing with the honey boo boo. Just as if the weather turns bad and only gingers can survive, then they are the most fit. Evolution does not care how the fittest are created, whether by man made environments or by natural influences. My favorite story is the American Indians who believed that albinos were unfit. The Albino Indians were considered inferior and were left behind when the warriors went on hunts for meat. Of course being left behind meant they were left with the women to procreate which meant more albinos. In this case the albinos were more fit and evolution favored them. Perhaps you do not so much believe in evolution as you do as creating a master race? I doubt I need to tell you where that leads.

Times of plenty

[chrisjbuck]

I think population dynamics show that in times of plenty (little natural selection, abundant food) populations explode, what the human population has been doing the last 100+ years. It's the spring that doesn't come or massive outbreak of disease or new dominant predator that culls the population, when that selection occurs the random genetic variations may give rise to competitive advantages. It is only after the population goes through the selection event that any mutations that proved advantageous will spread right through the population, then the population has evolved. Before the selection event the population is just randomly diverging.

True!

[rew]

Absolutely true!

Evolution works that way: In good times, a big population is generated that has great genetic variety. When bad times come along, the bad genetic variations will be removed from the population.

Suppose for instance that suddenly tomorrow all oaktrees had pollen that is deadly to most humans. The genetic variations builtup over the last 200 years might have provided a (possibly small) percentage of the population that is resistant to the deadly pollen. The result would be that a small group survives and starts working on a new gene-pool.

Yes, genetically we have been living in "good times" the last generations. More and more "slight defects" in the genetic pool are able to survive into mature ages.

A friend is totally colorblind. A genetic disadvantage, you'd say? Nope, his "grayvision" is a LOT better than that of most of us. Apparently he can spot camouflaged army-material from way further away than us normal people. When suddenly THAT becomes a winning trait (i.e. those that don't have it die), his descendants will form a larger part of the population.

This expansion of the gene pool also allows for combinations. Suppose the guy with the super-vision marries the gal with the super hearing?

Re:It's "Survival of the Fit-enough"...

[imidan]

Nonsense. Survival of the fittest is still occurring, it's just that the fitness criteria have changed. As you say, "babies that would have died lived on" -- but mostly that happens for those parents who have either the money or the health insurance (and the medical facilities) to deal with what would previously have been an "unfit" baby. Natural selection continues through societal means: the costs of birthing and raising viable children are inversely proportional to the health of the baby; children with difficulties are more expensive to raise.

There is still selection pressure, but in developed countries it's coming more from societal sources than from environmental sources. And the societal pressure isn't so worried about things like good eyesight or height, or those sort of physiological characteristics; it's about access to health care (whether that comes from parents with money or states with social safety nets).

And I would argue that even though humans are in charge of the programs and policies that affect these new fitness criteria, they are still fitness criteria because they are being applied to populations, rather than to individuals (except in very special and statistically insignificant cases). So, survival of the fittest is still alive and well, and being implemented inadvertently by human policy.

Re:Summary shows poor understanding of evolution

[EmagGeek]

I think what the submitter was getting as was that we are carrying a higher load of negative traits because natural selection is failing to eliminate them.

For example, one reason cancer is becoming more and more prevalent is because people who would normally die from it before they can reproduce, are instead being kept alive through technology to reproduce and transmit their higher susceptibility to cancer to the next generation.

(please not that I said "one reason," not "the only reason," because I know some environmental hot head is going to flame me for saying this)

Re:It's "Survival of the Fit-enough"...

[Johann Lau]

We will be a bunch of fat-ass couch potatoes eating chips watching CSI-dancing with the honey boo boo.

We are (d?)evolving into roughly two classes: the manipulated and the manipulators. Which isn't to say that everybody isn't a bit of both, but still: you are missing the "elite(s)" in that picture. I would argue they get dumber in their own ways, too, but they sure as fuck aren't sitting at home staring blankly at the TV. So that's a bit simplicistic, yeah?

Perhaps you do not so much believe in evolution as you do as creating a master race? I doubt I need to tell you where that leads.

It leads to exactly the situation we're in now, so what's your point? You don't honestly think the gap between individuals becoming more dumb/reliant, and organizations (and computations) more powerful, is anything but that? Or as George Carlin said, the Germans lost WW2, fascism won it.

Re:first

[MrKaos]

trolololol

Millions of years of genetic variation has produced....this