Are humans still evolving? Absolutely, says new analysis of long-term survey of human health

Oct 19, 2009

Although advances in medical care have improved standards of living over time, humans aren't entirely sheltered from the forces of natural selection, a new study shows.

"There is this idea that because medicine has been so good at reducing mortality rates, that means that natural selection is no longer operating in humans," said Stephen Stearns of Yale University. A recent analysis by Stearns and colleagues turns this idea on its head. As part of a working group sponsored by the National Evolutionary Synthesis Center in Durham, NC, the team of researchers decided to find out if natural selection — a major driving force of evolution — is still at work in humans today. The result? hasn't ground to a halt. In fact, we're likely to evolve at roughly the same rates as other living things, findings suggest.

Taking advantage of data collected as part of a 60-year study of more than 2000 North American women in the Framingham Heart Study, the researchers analyzed a handful of traits important to human health. By measuring the effects of these traits on the number of children the women had over their lifetime, the researchers were able to estimate the strength of selection and make short-term predictions about how each trait might evolve in the future.

After adjusting for factors such as education and smoking, their models predict that the descendents of these women will be slightly shorter and heavier, will have lower blood pressure and cholesterol, will have their first child at a younger age, and will reach menopause later in life.

"The take-home message is that humans are currently evolving," said Stearns. "Natural selection is still operating."

The changes may be slow and gradual, but the predicted rates of change are no different from those observed elsewhere in nature, the researchers say. "The evolution that's going on in the Framingham women is like average rates of measured in other plants and animals," said Stearns. "These results place humans in the medium-to-slow end of the range of rates observed for other living things," he added. "But what that means is that humans aren't special with respect to how fast they're evolving. They're kind of average."

More information: Byars, S., D. Ewbank, et al. (2009). " in a contemporary population." Proceedings of the National Academy of Sciences 106(42). doi: 10.1073/pnas.0906199106

Source: National Center

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User comments : 36

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dirk_bruere
2.3 / 5 (6) Oct 19, 2009
The only thing that has stopped evolving, or is going backwards, is likely intelligence. Modern societies select against it.
Fakeer
not rated yet Oct 19, 2009
aren't these traits already built-in mechanisms to adjust to the variations in the environment?
NeilFarbstein
3.4 / 5 (5) Oct 19, 2009
The only thing that has stopped evolving, or is going backwards, is likely intelligence. Modern societies select against it.

I never though of that in evolutionary terms. I know oppression is increasing but never linked it to devolution
ArtflDgr
1 / 5 (3) Oct 19, 2009
then socialism negates feedback of fitness where the less fit do better than more fit due to distribution, and the elite over all do the best being separate
Birthmark
2.3 / 5 (3) Oct 20, 2009
The only thing that has stopped evolving, or is going backwards, is likely intelligence. Modern societies select against it.

@dirk_bruere -- haha!! So true! I've always thought this, makes me sad in ways :/ but I'm too optimistic to think out future laid out by the ignorant.
Mikael
3 / 5 (2) Oct 20, 2009
The only thing that has stopped evolving, or is going backwards, is likely intelligence. Modern societies select against it.

Yeah, it's weird isn't it. You would think that a trait such as high intelligence ought to be favourable in any kind of future scenario... especially since the so called "trade off" (bigger brain, less power for other stuff) already happened.
Magus
4.7 / 5 (7) Oct 20, 2009
The only thing that has stopped evolving, or is going backwards, is likely intelligence. Modern societies select against it.

Evolution is not a forward backward thing. There is no goal for evolution so there is no forward or backward.
rab96
1.5 / 5 (2) Oct 20, 2009
Small changes in length and weight are not evolution. No new species have developed.
Archivis
3 / 5 (2) Oct 20, 2009
Well, short of inspecting every person on the face of the Earth, there's no way to know if there is a new species right under our noses. I've read another article on the subject that stated within the next few generations, we will have "humans" that are genetically incompatible with previous generations.

Interesting stuff!
SDMike
1.8 / 5 (5) Oct 20, 2009
Intelligent human have been able to contribute their intelligence by MOVING. Intelligent humans leave the oppression of the stupid by leaving to populate new territory. The stupid can't follow - they get eaten, can't survive, can't raise kids. Eventually the intelligent suppress competition, develop tech to meet new environments, etc. and the stupid move in. There is also regression in the intelligent's own kids that add to the population of stupid but early on stupid kid die. What the intelligent must now do is move again. This time into the solar system. The stupid can't follow. They will be unable to survive. Human's are wired up to do this. We evolved this trait or we wouldn't have gotten more intelligent. Neanderthal was constricted by climate and geology. Their intelligent couldn't move. Their race stagnated. Folks wonder why some of us want to, are driven to, go into space. Well, the need for the intelligent to move on, to leave behind the stupid, is part of being human
danman5000
1.6 / 5 (5) Oct 20, 2009
@SDMike: I love the picture you paint about our continuing struggle against The Stupid, it makes me feel empowered! :D You're definitely correct about space too - it'll be fun to watch neo-rednecks try to install screen doors on their space stations.
moj85
5 / 5 (5) Oct 20, 2009
To all people who think a new species is required for 'evolution' to occur: False.

Evolution does not require creation of a new species. A single species can evolve without creating two separate species. Evolution can DRIVE the creation of separate species but it is not the only marker. Genetic change in a population is evolution.
LKD
4 / 5 (6) Oct 20, 2009
danman5000: You're definitely correct about space too - it'll be fun to watch neo-rednecks try to install screen doors on their space stations.


May I remind you that the folks in the country, like myself, are far more intelligent than your generalization of incorrect facts. May I also remind you that the graduation rate of 'rednecks' vs city folk is staggeringly in our favor. I demand an apology from your despicable sense of humor.
Otto1882
3 / 5 (2) Oct 20, 2009
@SDMike: ... it'll be fun to watch neo-rednecks try to install screen doors on their space stations.

Funny, the pupils in 'redneck' states do much better in national standardized tests than their counterparts in the big cities... Strange that they manage this even though the average funding per student is about 2/3 of what those in the big cities get.. You are clearly an idiot with an unwarranted sense of arrogance. Who knew Armstrong, Farnsworth etc. were unevolved...
Magus
3 / 5 (2) Oct 20, 2009
I wonder what exactly some people mean when they say species. It is just an arbitrary term. Some see it to mean when a new organism can no longer breed with the previous organism from which it came. However this isn't allowed under evolution since it would be a too dramatic change. I wonder how people who think like this think the English language came about. Do they think the first person to speak English had no one to talk to?
frajo
1.5 / 5 (2) Oct 21, 2009
I wonder how people who think like this think the English language came about. Do they think the first person to speak English had no one to talk to?

There never was a "first person to speak English". All natural languages are the products of linguistic evolution, comprising components of a lot of other languages. E.g. Latin: ex-agere, populus, species, arbitror, prae-vius, evolvere, lingua, persona. E.g. Greek: terma, organo, drama.
Magus
3 / 5 (2) Oct 21, 2009
Did you miss the comparison. I know how languages evolve. I was referring to people who thing species pop into existence distinct from the previous generation.
frajo
3 / 5 (2) Oct 21, 2009
Did you miss the comparison. I know how languages evolve. I was referring to people who thing species pop into existence distinct from the previous generation.

Indeed, I got it wrong. Sorry.
chaman
2.8 / 5 (4) Oct 21, 2009
---------------------------------
There is no goal for evolution
---------------------------------

Then how about each of us -of one species- setting for ourselves the goal to become a non-violent, tolerant, careful and compassionate being?
Imagine one goal, achieved 6 billion times. Now, THAT would be evolution...or the end of it.
defunctdiety
1 / 5 (1) Oct 21, 2009
IMO a big part of being qualified as evolving is that a given evolution must make that individual more likely to successfully reproduce and have successfully reproducing offspring. In that regard, humans stopped evolving biologically a long time ago I think.

However perhaps the evolution then moves to sociological traits. As it could be asserted that one's societal attributes now affect who successfully passes on their genes and have offspring who successfully reproduce and so on. Which since there's so many facets of society, this evolution can take many forms, behavioral, economical, etc.

But regardless of the form, does evolution (sociological) now take place on an individual level then, as societal attributes are not (as easily/commonly?) passed on through genes as biology/phenotype, etc? i.e. the societal phenotype is determined more by environment and society and ultimately the individual.

It then becomes every individual's responsibility to evolve themself i.e. chaman's post?
Lars
1 / 5 (2) Oct 22, 2009
To all people who think a new species is required for 'evolution' to occur: False.
...Genetic change in a population is evolution.

There are multiple meanings of 'evolution'. The meaning used in the title of this article is the weakest: namely, a shift in proportions of phenotypes in a population. Unfortunately the ambiguous word often misleads the uninformed, who conclude that the above study provides support for a natural origin of complex functions, systems, and major taxa.
defunctdiety
5 / 5 (2) Oct 22, 2009
who conclude that the above study provides support for a natural origin of complex functions, systems, and major taxa

Just so we're all on the same page, is this as opposed to the informed, who assume a supernatural origin of complex functions, systems and major taxa?
ThisIsDarwin
not rated yet Oct 22, 2009

There are multiple meanings of 'evolution'. The meaning used in the title of this article is the weakest: namely, a shift in proportions of phenotypes in a population. Unfortunately the ambiguous word often misleads the uninformed, who conclude that the above study provides support for a natural origin of complex functions, systems, and major taxa.


So what meaning should be used to best communicate it's authenticity to the general public and the doubters?
danman5000
1 / 5 (1) Oct 23, 2009
Wow I didn't think I'd generate that much hate over that "redneck" joke. Calm down you two, no need to break out the pitchforks and torches. It's not like I said "All people in Kentucky are stupid," I just made a reference to a stereotype and a series of related jokes. Did you assume SDMike was talking to you when he talked about stupid people? I was saying the same thing, just with a different word. I don't doubt that people in the country are just as capable and intelligent as anyone else, I thought that would be obvious. Apparantly people on this site don't have much in the way of a sense of humor.
Chocolate_Bacon
3 / 5 (1) Oct 23, 2009
I fail to see how this is even an issue. The whole of recorded human history is such a miniscule scrap of time compared to the massive scope of life's flow that drawing conclusions from the past few thousands of years is foolish at best.
Sean_W
1 / 5 (2) Oct 24, 2009
Cities make people who are violent and stupid more visible by bringing them into contact with more normal people so cities seem to be making people violent and stupid. They also atract people who need social services and hand outs to get by so they get all the homeless and severly mentally ill from the region but that does not mean that they contribute to the gene pool of the cities or that cities are selecting for stupid or crazy people. I would suspect that the mixture of gang violence, opportunities to get in trouble with the law (leading to jail) and other factors make cities and modern societies more selective for intelligent and social people. This could explain why some genetic studies have shown that the speed of natural selection has increased with the advance of civilization. For the first time ever, over half of our species lives in an urban setting and that proportion increases constantly. What sort of effects this has over the next few generations will become evident.
Sean_W
3 / 5 (2) Oct 24, 2009
Wait! This story seems to say that women are going to be shorter, fatter and be having their first kids in high school or earlier. Is there something we can do to stop that?
peteone1
1 / 5 (1) Oct 24, 2009
[Evolution does not require creation of a new species. A single species can evolve without creating two separate species.]
True, but what is the limit of that speciation event? I don't believe that event can be considered anything than a horizontally based microevolution event.

[Evolution can DRIVE the creation of separate species but it is not the only marker. Genetic change in a population is evolution.]
Yes but what is the origin of the genetic information hidden in the codons of the genome in question? Undirected mindless forces of mutation and natural selection could not by themselves have built the genetic info content, that I believe comes from a Mind of such magnitude might as well invoke the name of God as the author of the evolutionary process. That is not a scientific conclusion but a philosophical/metaphysical one based on logical conclusions of existing data. The assumption of purely natural forces minus any intelligent designer is also a purely metaphysical one.
CarolinaScotsman
3.7 / 5 (3) Oct 25, 2009
"I just made a reference to a stereotype and a series of related jokes....I thought that would be obvious. Apparantly people on this site don't have much in the way of a sense of humor."

Apparently, people on this site are tired of being belittled by unthinking stereotypes perpetrated by people with no sense of their own bigotry.
kasen
5 / 5 (1) Oct 25, 2009
This story seems to say that women are going to be shorter, fatter and be having their first kids in high school or earlier. Is there something we can do to stop that?


If the standard of female beauty remains tied with BMI, depression and social anxiety rates are kept on the rise, pornography, prostitution and recreational drugs proliferate, we're safe. The media has been making sure of that for a while now.

Cultural/sociological trumps biological, as far as reproduction is concerned. That should be the large-scale picture. 2000 females over a 60 year period isn't a large-scale picture.
frajo
1 / 5 (2) Oct 25, 2009
If the standard of female beauty remains tied with BMI, depression and social anxiety rates are kept on the rise, pornography, prostitution and recreational drugs proliferate, we're safe.

Pornography, prostitution, and recreational drugs increased rapidly in number and amount over the last 10000 years? History as well as the Bible tell us a different story.

A low BMI in yonder times meant illness and a burden for the community. Only some generations ago progress finally allowed us to see slim women without worrying. The popular appeal of slimness is just a temporary reaction to eons of mistrust.
kasen
3 / 5 (2) Oct 25, 2009
Pornography, prostitution, and recreational drugs increased rapidly in number and amount over the last 10000 years?


Of course not. I'm referring to the last few decades. As the speed of culture propagation increased explosively, social trends have begun to predominate biological ones.

That is not to say that we have stopped evolving biologically, just that the main driving forces are no longer biological in nature and as such, we can't make accurate predictions based on them.
Archivis
not rated yet Oct 26, 2009
@peteone1 - Evolution is a process of trial and error that takes place over millions of years. Personally, I feel if there were an intelligent designer behind the whole thing, that it would progress to the desired result directly without this long drawn out process that often times leads to nothing.

And since this topic is drawing some hot tempers, let me say also that I do not discount some form of intelligent design, I just don't see it evident within the process of evolution. But then, that's why so many "bible thumpers" (generalization, not accusation) try to discount evolution.

Perhaps we will be able to answer these questions within our life time, I personally can't wait to find out who is right.
7734
not rated yet Oct 28, 2009
I concur with both Archivis and Peteone. I do not have any problem with a higher intelligence or grand designer. (www.y-origins.com/) has some interesting articles on this subject. I do not understand however, why, when the name God is invoked as the grand designer, higher intelligence, then everyone immediately jumps on the religious bandwago. For me I can see no connection between a scientific God (grand designer) and the God of the "Bible" as portrayed by all of the Churches, this God was created by man!I feel that the sooner the scientific "God" the grand designer, and the other "God" of the religious Bible followers become divorced in the minds of truth seekers, the better it will be for this ongoing creation v evolution debate. The flawed Bible, with all its politically censored writings was written by man. The ewidence for a grand designer is a different story, and scientific fact, if current scientific thinking is correct.Lets remove the Religious thing from the whole debate.
moj85
5 / 5 (1) Oct 28, 2009
From peteone1:
Undirected mindless forces of mutation and natural selection could not by themselves have built the genetic info content, that I believe comes from a Mind of such magnitude might as well invoke the name of God as the author of the evolutionary process.


That statement is not backed up by any scientific reasoning. You _believe_ that genetic content can't be created by natural selection. Via evolution, it can (and by definition), has to be.
Ethelred
3.7 / 5 (3) Oct 31, 2009
The reason Peteone1 thinks evolution can't create genetic content is that he apparently has only heard about evolution, mostly from Creationists. He clearly hasn't actually looked into how the process works.

ID fans consistently fixate on mutation as a random process and pretend Natural Selection IS mutation. Which where Pete falls down.

Natural Selection comes AFTER mutation. It is simply a name for the inherent culling by the environment of any changes that decrease an organism's chance of reproducing. Any mutation that increases an organism's chance of reproducing would tend to be preserved. This is how the environment affects the information in the genome.

The other thing people tend to not know is that some mutations consist of duplication of parts of the genome. The duplication makes it possible to have an unmodified copy and a modified copy of a gene. Thus allowing the amount of information in the genome to increase.

Ethelred