Study shows humans still evolving
October 4, 2011 by Deborah Braconnier
(PhysOrg.com) -- A new study published in the Proceedings of the National Academy of Sciences provides evidence of human evolution and rapid genetic changes suggesting that, contrary to modern claims, technological and cultural advancements have not halted the evolutionary process in humans.
The new study, led by geneticist Emmanuel Milot from the University of Quebec, looked at a group of women from the remote island town of Ile aux Coudres in Quebec, Canada. The team looked at the birth, death and marriage records kept by the Catholic Church in the town. They were specifically looking at the data from women who married between 1799 and 1940.
What they discovered was that within that 140 year time frame, the age that the women conceived their first child dropped from 26 to 22. Looking at cultural, social and economic differences in the women, the researchers were able to determine that 30 to 50 percent of this variation in age was explained solely by genetic variations.
This island town was settled by 30 families between 1720 and 1773 and researchers believe that a genetic change occurred in order to provide more time for women to produce a larger number of children in order to grow the population. While the researchers did not look at which specific genes may have been altered over time, they believe possible reasons could have been a change in the age in which the women hit puberty and heritable personality traits which pushed them to wanting to start families earlier. These changes were a response to natural selection and the need for a higher number of children in order for gene lines to survive into the future.
This is not the first study to show that human evolution is still happening. Recent studies include the Tibetans evolutionary change to adapt to the lower oxygen levels found in their high altitude environment. This change has only occurred throughout the last few hundred generations. Other studies show that humans have only evolved the ability to tolerate lactose in their systems over the last 5,000 or so years.
While many scientists have trended toward the idea that changes in populations are typically due to environmental or social influences in todays societies, this study shows that while these factors do play a role, genetic changes and evolution are also still very much a part.
More information: Evidence for evolution in response to natural selection in a contemporary human population, PNAS, Published online before print October 3, 2011, doi: 10.1073/pnas.1104210108
Abstract
It is often claimed that modern humans have stopped evolving because cultural and technological advancements have annihilated natural selection. In contrast, recent studies show that selection can be strong in contemporary populations. However, detecting a response to selection is particularly challenging; previous evidence from wild animals has been criticized for both applying anticonservative statistical tests and failing to consider random genetic drift. Here we study life-history variation in an insular preindustrial French-Canadian population and apply a recently proposed conservative approach to testing microevolutionary responses to selection. As reported for other such societies, natural selection favored an earlier age at first reproduction (AFR) among women. AFR was also highly heritable and genetically correlated to fitness, predicting a microevolutionary change toward earlier reproduction. In agreement with this prediction, AFR declined from about 2622 y over a 140-y period. Crucially, we uncovered a substantial change in the breeding values for this trait, indicating that the change in AFR largely occurred at the genetic level. Moreover, the genetic trend was higher than expected under the effect of random genetic drift alone. Our results show that microevolution can be detectable over relatively few generations in humans and underscore the need for studies of human demography and reproductive ecology to consider the role of evolutionary processes.
© 2011 PhysOrg.com
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Oct 04, 2011
Rank: 5 / 5 (6)
In that remote island town community religion could have been one of those pressures when considering the age of conception, though I don't see proof of evolutionary change.
Oct 04, 2011
Rank: 3.9 / 5 (7)
Oct 04, 2011
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Oct 04, 2011
Rank: 5 / 5 (1)
Oct 04, 2011
Rank: 1 / 5 (3)
this should be nominated for an Ig Nobel Prize
Oct 04, 2011
Rank: 5 / 5 (8)
Turns out a large chunk of the population suffers from this problem, and it can lead to a whole range of autoimmune disorders (like lupus and diabetes) later in life. That's an example of a human-induced environmental factor exerting powerful selective pressure today: there was no issue with gluten intolerance until agriculture became wide-spread and human diets changed toward heavy dependence on cereals and processed grain such as bread and pasta. Just like with lactose intolerance, gluten intolerance puts people who exhibit this ancestral trait at a selective disadvantage.
In addition to "natural" adaptations like Tibetan high-altitude tolerance or African sickle cell trait, we drive our own evolution by changing the very environment in which we live.
Oct 04, 2011
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Oct 04, 2011
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@Robert_Wells:
No, it shouldn't. Oblivious results for educated man bad science.
Oct 04, 2011
Rank: 5 / 5 (3)
This study does not in my mind indicate evolution however. Although given time changed habits may become evolutionary changes it still appears at this stage that changes in first birth dates could be more down to environmental factors than evolutionary factors.
Oct 04, 2011
Rank: 1 / 5 (1)
We are a complex system that is constantly adapting to its environment. Adaptations are rapid and happen within one generation to the next. If adaptations were slow and random we would not be here. Another "Cornflake Crunch" study.. a waste of time and effort.
Oct 04, 2011
Rank: 3.3 / 5 (3)
Oct 04, 2011
Rank: 5 / 5 (1)
Other traits that might increase in modern populations would include ability to deal with both accute and chronic exposure to toxins and better immune systems due to greater exposure to more pathogens. Surviving extended periods after massive injuries would not have been that beneficial to our ancestors but if that survival ability can get ppl to an E.R. it would suddenly be a more beneficial trait.
Oct 04, 2011
Rank: 4.1 / 5 (7)
I doubt it. Epigenetic changes aren't long lasting due to the limited stability of DNA methylation, which also means that altered DNA methylation often cannot become subject to natural selection.
Oct 04, 2011
Rank: 5 / 5 (7)
Oct 05, 2011
Rank: 4.4 / 5 (7)
Without a GENETIC test they are speculating no matter how good the rest of the study might have been.
That is something that people that don't understand anything about evolution might say. Change comes in response to the environment. IF having children earlier is successful then it would be genetically conserved BUT since women are fully capable already of having children MUCH earlier there is NO reason to assume a genetic change was involved when behavior covers it completely.>
Oct 05, 2011
Rank: 5 / 5 (2)
Handwaving UNLESS the studied who had the most children. With a full tree of descent. Age of puberty was not involved in this since it occurs long before 22 or 27. The abstract doesn't give me a clue on this but someone clearly doesn't understand the evolutionary process. The article author or the scientists?
Which is not something that evolutionary processes can manage. Only someone without a clue that evolution has no plan and is just a process would make such an unrealistic claim. Same weasel words as above. SWWAA.>>
Oct 05, 2011
Rank: 5 / 5 (2)
Unfortunately it did no such thing. They may have been able to do so IF they did the work AND checked the genetics or at least tracked the fertility rate for all the women by actual familial descent but I can't tell from the article or the abstract.>>
Oct 05, 2011
Rank: 3.7 / 5 (3)
However I think that nanotech_republika_pl may actually be correct this time. Epigenetic effects could cover any biological adaptation that may have occurred. They are not inheritable though so I suspect that culture and economics caused almost all if not all the change.
Since this is a Physorg article I would appreciate it if the writer was willing to clear this up. I would be stunned as well since Physorg sometimes seems to be unwilling to even acknowledge that there are people commenting here beyond that idiotic 'brevity is somehow witty' remark which they clearly did not understand in the first place.
Ethelred
Oct 05, 2011
Rank: 1.2 / 5 (5)
Oct 05, 2011
Rank: 1 / 5 (1)
- Ethelred
Another series of outstanding comments from you, Ethelred. Keep in mind that the less experienced article writers may not have your experience and insight. Theres plenty of crap they sift through, doing the best they can and need to produce some copy for publication. I am sure the writers read the comments and from (mostly) well reasoned comments, like yours, learn.
Attack the article content by all means but give the writers a break.
Oct 05, 2011
Rank: 5 / 5 (2)
Thousands of years seems to be more than enough. Humans have adapted to the high mountains in South America in what seems to be at most 10,000 years. Evolution does not always creep along. One hundred generations is just 2000 or so years.
Look at how much change has been forced on dogs or pigeons since the Brits started breeding them.
I admit that Stephen J. Gould doesn't know anything anymore due to being dead and not having been an Anthropologist in the first place but he and many others would disagree with that statement given the opportunity.
Ethelred
Oct 05, 2011
Rank: 3 / 5 (2)
A LOT of articles here do this sort thing. A bit more care in word choices would help a lot. I was actually hoping, yes really, that the author would clear it up a bit. Unfortunately I can't recall a single such case where the author ever replied to any comments. Some of the scientists have. Some have even been reasonable.
Physorg consistently refrains from consorting with the readers in anyway except to anonymously delete posts or ban people. They almost never explain. The last time the communicated in a way that implied they were aware that humans actually read the site was when they put the 1000 character in.
I am trying to convince them to CHANGE that execrable behavior.
Ethelred
Oct 05, 2011
Rank: 1 / 5 (1)
Oct 05, 2011
Rank: 1.6 / 5 (5)
You have stated what I warned against: confusing adaptation with evolution. Adaptation, even selective genetic adaptation, does not creep along, no, but evolution always will. But if you are correct, then perhaps you can enlighten me: What have deep-breathing Tibetans evolved to become?
Looked at another way, multiple generations of almost any ethnic sub-group, all with unique traits of their own, could perhaps adapt as well as Tibetans to high altitude, given time. But evolutionarily, they are, and always will remain identical to us, homo sapiens, genus: homo, Family of Man.
Oct 05, 2011
Rank: 2.3 / 5 (3)
Oct 05, 2011
Rank: 2.3 / 5 (3)
Oct 05, 2011
Rank: 4.6 / 5 (8)
They are the same thing. You aren't kidding anyone here.
Humans with high altitude adaptations. Evolution is not just a change in KIND. Yes I know where you are coming from. Fundamentalism. You are not the first to try to change English and science to fit your religious needs.
Adaptation IS evolution and the only reason for evasions like this is to support a belief in Genesis.
So when was the Flood? Where is ANY REAL physical for it.
Ethelred
Oct 05, 2011
Rank: 5 / 5 (1)
Cities have driven human evolution by being a great way to die due to disease. This isn't an obvious sort of evolution until you like at what happened when city adapted Europeans brought diseases to the New World.
Ethelred
Oct 05, 2011
Rank: 4 / 5 (4)
@Ethelred,Not so much city-adapted as agriculture- and livestock-adapted. There is a lot of inter-species pathogen hopping between humans and livestock, and those human lineages that have dwelt for a long time alongside livestock have evolved various forms of disease resistance and immunity as a consequence.
Oct 05, 2011
Rank: 1.8 / 5 (4)
Wow, "religious needs" and "fundamentalism"? Really? Okay, now I give up. Why let facts get in the way when arguments can be made with non-sequiturs.
Oct 05, 2011
Rank: 1 / 5 (1)
http://www.pnas.o...10SI.pdf
And here a fast, unqualified take from a physicist:
http://infoproc.b...bec.html
And here an OT special treat for Ethelred or others:
http://iopscience...1/115001
This is the only handle and approach I have to grasp the large and small of physics. Click on "download abstract video" also.
It is the only indemnification for the loss of time Ethelred has spend on the word "spactime" that makes sense to me.
Yes Bluehigh. Outstanding comments deserve such attention.
Oct 05, 2011
Rank: 4.4 / 5 (7)
You mean like what you have done?
So where are these 'facts' of yours that support that ridiculous assertion? How about I give you a real fact?
Even small changes in the HOX genes can lead to drastic changes, such as where the head goes and which regions of the body grow appendages. These genes are master controllers of other genes and help to direct the building of body units, such as segments, limbs, and eyes.
So evolving a major change in basic body layout can happen literally in a single generation. I would not call that 'creeping along'.
You realize that as a species, there are enormous genetic differences between individuals? We're not just a single, monolithic group.
Oct 06, 2011
Rank: 5 / 5 (2)
Evolution is genetic adaptation. It is NOT limited to speciation.
There were no non-sequiturs in my post. It was all relevant.
So how about you start using facts instead of nonsense?
Anytime you want to engage in an actual discussion feel free to start. You can start by giving us a clue as to you think that genetic change is not evolution.
Ethelred
Oct 06, 2011
Rank: 5 / 5 (1)
Nonsense! Evolutionary adaptations are slow and non-random - it is only the mutations and other genomic changes that are random. The selection that brings about adaptation isn't random.
Oct 09, 2011
Rank: 1.4 / 5 (11)
Oct 09, 2011
Rank: 5 / 5 (1)
Fundamentalist Dogbert disagrees with you. Of course his logic is more than a bit strained but it is based on Genesis.
AND why do you believe that when the world and the Bible do not agree. I go on the world. You seem to want to go on the writing of ignorant men. If a god was responsible for the Bible why is Genesis pretty completely wrong?
Yet we have. Mutations happen. Natural selection happens thus evolution happens. The only evolution cannot occur is for a god to interfere with each persons life to both stop mutation and selection. Since humans DO have mutations and we DO die then no god is interfering.>>
Oct 09, 2011
Rank: 5 / 5 (1)
Now why do you believe that? Please explain and it would be really good if you produce some REAL evidence, that can be checked, that might convince others that your beliefs reflect reality instead of being the fantasy they appear to be.
Also I think it is pretty clear that Dave57 has scarpered off. Thus strongly implying that I nailed it. He was almost certainly engaging in stealth Creationism.
OverweightAmerican , you have far more guts than he does.
Ethelred
Oct 09, 2011
Rank: not rated yet
Ethelred" Multiple meanings - humorous.
I'm no God basher, nor am I a follower. If there is a God creator then we are as far beneath its notice as It is above ours. We travel in different circles... If you have religion, which to me is less about God and more about man, that's fine for you. Just stay out of my face and out of my way and we'll get along fine. When It comes to religon on a science site, I think "Don't ask, don't tell" could be an appropriate policy.
As for Dave57, he does not seem to be a fundementalist evolution denier. After all he did state: "Evolution does not always creep along." and "Adaptation, even selective genetic adaptation, does not creep along, no, but evolution always will." Obviously he's not denying evolution. From my perspective he was simply arguing the use of the definitions. But the funny part was that he even argued against himself with opposing statements in the same post
Oct 09, 2011
Rank: 1 / 5 (4)
Oct 09, 2011
Rank: 5 / 5 (1)
Precipitation continues to fall from the sky. This "Rain" still used by plants to grow.
Oct 09, 2011
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Oct 09, 2011
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I swear, some of these "studies" that physorg reports are just ridiculous. Anyone that knows anything about evolution knows that humans are of course still evolving and likely will be for the foreseeable future.
Oct 09, 2011
Rank: 5 / 5 (1)
He seems to asserting that evolution is equivalent to speciation, which is ridiculous, as speciation is a RESULT of evolution. Any change in an allele frequency in a population is an example of evolution.
Oct 09, 2011
Rank: not rated yet
It's difficult to predict how this will affect us as a species considering the remarkable rate of technological advancements and social changes, but if all things remained constant it wouldn't be long (a few hundred generations, a few thousand years) before you wouldn't be able to tell an Asian from a European from an African simply by looking at them. These genetic differences in appearance developed while the individuals were split into separate populations by insurmountable geographic barriers (oceans, namely). We have since bridged these barriers and allowed individuals to flow freely between these populations.
Oct 10, 2011
Rank: 5 / 5 (1)
That is a now standard attempt to replace the Evil of Evolution with tolerated adaptation. See Answers in Genesis for the acceptance of adaptation being unavoidable even by Kent Hamm.
No its not obvious. He is trying to replace it with adaptation. Now if he actually replies and says evolution and speciation occur THEN and only then will I have a reason to agree.
That is likely due to his not liking adaptation either.
We can't know what Dave57 REALLY means until he quits playing around and gets to the point. Please look at how long Dogbert has tried to evade telling us what he really thinks.
Ethelred
Oct 11, 2011
Rank: not rated yet
Ethelred"
There is a glimmer of hope. Those who hesitate and have difficulty explaining their opinions usually have doubts. Those with certainty don't hesitate. When there is doubt there is room for change.
Oct 19, 2011
Rank: 1 / 5 (1)
A.
Change during human evolution could have led to bigger brains.
http://www.scienc...a_smarts
New Genes, New Brain
http://the-scient...w-brain/
B.
On Culture And Genetics, Horses And Wagon
http://universe-life.com/2011/08/26/on-culture-and-genetics-horses-and-wagon/" title="http://http://universe-life.com/2011/08/26/on-culture-and-genetics-horses-and-wagon/" rel="nofollow" target="_blank">http://universe-l...d-wagon/
If you saw it once, you saw it a million times: its the horses pulling, not the wagon pushing !
C.
Enough with the AAAS trade-union mandated science peer-review ignorance. Its culture that modifies genetics, not genetics that modifies culture.
Dov Henis (comments from 22nd century)
http://universe-life.com/
Oct 28, 2011
Rank: not rated yet
Oct 29, 2011
Rank: not rated yet
Why would it? Darwin's theory is about Natural Selection of organisms and it is not about cultures.
Also wrong. Homo Sapiens have been around for least 150,000 years. Still shorter then Homo Erectus but MUCH longer then 6,000. This fixation with 6000 is kind of suspicious because it isn't even right about the Sumerians as that is 5,000. 6000 is a favorite of Biblical literalists.>>
Oct 29, 2011
Rank: 5 / 5 (1)
Maybe someday, maybe the brain will need extensive biological and nanotech modification first.
Ethelred
Nov 01, 2011
Rank: not rated yet
Most of our modern cities wouldn't last very long left to Mother nature's gentle hand - don't we exist?
Nov 01, 2011
Rank: 5 / 5 (1)
I have seen no evidence that supports that. Despite having seen the claim many times. The earliest cities have all been quite small. More like small towns.
The evidence would last many thousands of years.
So far Mas_Hamad has made just that one post. Highly indicative of that post being a religious hit and run. Might even be an extremely rare Islamic religious post.
So then Steve, do you have any links to the alleged physical evidence. It has always been wishful so far but you have something better. It isn't impossible.
Ethelred
Nov 01, 2011
Rank: 5 / 5 (2)
The emergence of agriculture is dated roughly to somewhere within the last 10,000 years; ditto for domestication of livestock.
Never mind lack of archeological evidence: there is not even any theoretical ground for expecting any cities pre-dating those technological innovations. Prior to those inventions, human tribes were nomadic hunter-gatherers, and all of their construction was most likely along the lines of teepees/yurts/wigwams.
Nov 03, 2011
Rank: 1 / 5 (1)
Our history is replete with discoveries, which would imply that at any point in time there is much more to learn. Just to be clear: of what has been done or created over the many thousands of years, I give all credit to humanity, not some fanciful ancient god or astronaut.
Some civilization seems to have basically covered the globe (some think it was the east Africans 50,000 to 70,000 years ago) encouraging the building of pyramids - a wholly un-needed expenditure of energy that provided no known functional purpose. So, why would these appear all over?
What do I know? Not enough, obviously. But I would not support the concept that if we haven't found evidence, it never existed. That would be like believing that if you can't see germs they are harmless.
Nov 03, 2011
Rank: 5 / 5 (1)
To presume something exists without evidence or reason is silly at best
What evidence supports that? I ask because all I have seen so far is utter crap based on the Atlantis nonsense. And because I asked you already and -- nothing.
Otto thinks we have Secret Masters. He has exactly as much evidence. Whatever he can make up.
Nonsense. We know when they were built and wasn't tens of thousands of years ago.
They felt they needed it. Funeral and religious monuments exist throughout the world. We know EXACTLY what the Aztecs used them for. They cut out hearts on the alters at the top.>>
Nov 03, 2011
Rank: 5 / 5 (1)
They don't. I assume you are referring mainly the pyramids in the New World. Large monuments are EASY to build that way is why. The ones in the New World were built and rebuilt over many generations with the older version as the foundation for the new. They built many if not all of them for religion. There is nothing magical or fantastic about any of them. They are the easiest big building to make. A large square for instance would burst its its walls. That is why the Gothic cathedrals have those buttresses.
A pyramid is nothing but a pile of rocks at the angle of repose. The only tricky part was the inner passages in the Egyptian pyramids and they had lots of time figure it out.
I was going to say something smart assed but the fact is no one knows enough except for idiots like Kevin. He thinks he knows enough is outraged that anyone would want to know anything outside the Bible.>>
Nov 03, 2011
Rank: 5 / 5 (1)
I don't see why you would suppose that something might have existed when all you have is bullshit people made up without a shred of evidence.
There is evidence for them killing. There is NO evidence to support the concept of an ancient civilization.
Its a bunch nonsense made up by charlatans and the gullible based on ONE story that Plato claimed he heard as a child and Plato didn't even bother to finish the story. From that one unfinished story, which may have been inspired by Crete, Edgar Cayce The Not-Really Sleeping Fraud and his chief follower produced vast amounts of purest bullshit. His chief follower was a ludicrously stereotypical gypsy con-artist so over the top it is nearly impossible to write about her without looking like a bigot towards the Rom.
Ethelred