Humans have stopped Evolving in Developed Countries

[Luminal]

In developed countries, the sick, poor, and disabled are taken care by means of the great excess those nations have at their disposal. The poor or sick may or may not lead happy or fruitful lives, but their survival is not at stake in any significant manner.

 

Success in a developed countries is defined by material belongings, academic achievement, and emotional factors such as happiness, satisfaction, and contentment. These do not drive natural selection.

 

In fact, those that devote their time to material or academic success have less time to raise a family as those that focus on a "social life" or "family life" and do not pursue a high status.

 

So, in one sense, those that are less successful in society usually have more children.

 

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Another major factor is that most people in developed countries die after they've had all of their children, the average life span being in the 70's (soon to be in the 80's).

 

Factors such as heart disease and lung cancer which would normally favor the survival of those who thought high fat food tasted bad and those who are not easily addicted to nicotine, do not have any effect because the deaths occur well past the point of passing on genes. Thus, evolution does not occur and people keep on loving high fat food and being addicted to nicotine.

 

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In fact, evolution might even be going backwards because those that focus less on success and more on rearing a family (such as a couple of high school dropouts who had two children before they were 20 and three more later) have more children in the end. The offspring of the "non-motivated" will exponentially outnumber those of the "motivated" in as little as several generations, even if the ratio of child bearing is as small as 1.2:1 (which I believe it is actually much more than that).

 

Over numerous centuries, the effect could be quite dramatic, to the point where intelligence and motivation for success become extremely rare in a society and having numerous children is the naturally favored course for humans in developed countries.

 

Thankfully, I believe genetic engineering will advance and intervene before this becomes a severe threat to our species, but it is very interesting to consider, as the effects are even evident today in our society.

[ydoaPs]

In developed countries, the sick, poor, and disabled are taken care by means of the great excess those nations have at their disposal. The poor or sick may or may not lead happy or fruitful lives, but their survival is not at stake in any significant manner.

And these sick people live longer(say, long enough to reproduce more often than without being in a developed country). Now, some percent of these sick people are suffering from GENETIC diseases. Since they, on average, live longer and are more likely to reproduce than before, they are also more likely to pass on these defective genes to offspring. Thus, the number of defective alleles in the population is greater than that of a third world country. So, there is an allele shift, and thus evolution.

[NeonBlack]

Also, I would say that evolution cannot "go backwards" as YD said, evolution is just a change in a population's genes.

[Luminal]

And these sick people live longer(say, long enough to reproduce more often than without being in a developed country). Now, some percent of these sick people are suffering from GENETIC diseases. Since they, on average, live longer and are more likely to reproduce than before, they are also more likely to pass on these defective genes to offspring. Thus, the number of defective alleles in the population is greater than that of a third world country. So, there is an allele shift, and thus evolution.

 

I guess that depends if your definition of evolution includes changes that increase the survivability of life.

 

If your definition is simply any changes whatsoever, negative or positive or benign, then sure, evolution is still taking place. At looking at the definitions in several dictionaries, it would seem "evolve" tends to mean progressive changes in other fields, yet in biology it tends to be intentionally vague in regards to progress.

 

Either way, my point stands. Humans in developed countries are not genetically progressing toward survivability, and in fact, are regressing toward traits that do not favor intelligence, motivation, and responsibility.

[insane_alien]

ah so they have only stopped evolving if you discard the accepted scientific defnition of evolution and use YOUR definition.

 

see you've been following scientific method there.

[ghstofmaxwll]

Humans in developed countries are not genetically progressing toward survivability,

Yes they are! They are progressing towards larger populations and more variety of genes...Todays bad genes could be connected to tomorrows cutting-edge for all we know.

and in fact, are regressing toward traits that do not favor intelligence, motivation, and responsibility.

Which is still evolving, if this is indeed so... Its not regression, it is adapting to a change in environment - evolving !

 

By your rationale, would you say the Sloth has regressed, because it has become slow and lazy? Or would you say it has refined its efficiency to living in an environment lacking predation?

[Luminal]

ah so they have only stopped evolving if you discard the accepted scientific defnition of evolution and use YOUR definition.

 

see you've been following scientific method there.

Which is still evolving, if this is indeed so... Its not regression, it is adapting to a change in environment - evolving !

 

By your rational, would you say the Sloth has regressed, because it has become slow and lazy? Or would you say it has refined its efficiency to living in an environment lacking predation?

 

To respond to both, natural selection, the fuel of evolution, is missing in developed countries. Humans are not "adapting to change." Even sloths have natural selection.

 

I think the point is being missed by semantics, which my least favored part of science.

 

With natural selection missing, beneficial evolution cannot occur. Will you dispute this?

 

With nothing to remove the unfavorable traits (which I am certainly not advocating), there is nothing to drive progress toward survivability, which humans have historically found through intelligence.

[Royston]

Which is still evolving, if this is indeed so... Its not regression, it is adapting to a change in environment - evolving !

 

Exactly, I think Luminal is under the impression that humans, or more specifically intelligence is somehow what evolution is converging to. Which, not only being an anthropic view (which isn't scientific), also shows a misunderstanding of the evolutionary process.

[Luminal]

Exactly, I think Luminal is under the impression that humans, or more specifically intelligence is somehow what evolution is converging to. Which, not only being an anthropic view (which isn't scientific), also shows a misunderstanding of the evolutionary process.

 

No, this is not what I am saying, and I believe it is also unscientific to put words in another's mouth.

 

When natural selection is removed, beneficial evolution cannot take place, except by sheer randomness (the kind that creations mistakenly refer to in normal evolution).

 

Since benign and negative mutations occur more often than beneficial mutations, and without natural selection to do the picking, evolution that degrades a species is the natural course.

[Mr Skeptic]

When natural selection is removed, beneficial evolution cannot take place, except by sheer randomness (the kind that creations mistakenly refer to in normal evolution).

 

It is impossible to remove selection pressures. If you're born with no head, you are gonna die, no getting around that. At most the selection pressures will be reduced. Whether that is a bad thing is not as clear cut as you may think. During mass extinction events, the selection pressures were much harsher, was that a good thing?

 

Since benign and negative mutations occur more often than beneficial mutations, and without natural selection to do the picking, evolution that degrades a species is the natural course.

 

It just means more variability, which is often a good thing. It may allow changes that would have been impossible before. However, it could also make us temporarily weaker. That weakness would be eliminated very quickly in a few harsh generations though.

 

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Regardless, the point is moot since there is no way we are going to wait around for evolution to do its thing. Genetic engineering > evolution.

[Luminal]

It is impossible to remove selection pressures. If you're born with no head, you are gonna die, no getting around that. At most the selection pressures will be reduced. Whether that is a bad thing is not as clear cut as you may think. During mass extinction events, the selection pressures were much harsher, was that a good thing?

 

It was, at least for us. Mammals and birds would not have arose without an extinction event.

 

As for being born without a head, of course natural selection still acts on an extreme where you are born dead already. But a baby born with no limbs... could very well live to pass on genes in our society.

 

It just means more variability, which is often a good thing. It may allow changes that would have been impossible before. However, it could also make us temporarily weaker. That weakness would be eliminated very quickly in a few harsh generations though.

 

It will not be eliminated, though. Humans will make sure to take care of the disabled. Again, I'm certainly not advocating we don't, but the genetic implications are worth noting.

 

Regardless, the point is moot since there is no way we are going to wait around for evolution to do its thing. Genetic engineering > evolution.

 

Agreed.

[ghstofmaxwll]

 

 

 

It will not be eliminated, though. Humans will make sure to take care of the disabled. Again, I'm certainly not advocating we don't, but the genetic implications are worth noting.

 

 

 

Agreed.

 

No! It takes resources to look after the disabled, if there are no excess resources the disabled will be first to go. Thats why war-torn countries allow disabled children to die young and malnourished in poor conditions, at best.

[Royston]

No, this is not what I am saying, and I believe it is also unscientific to put words in another's mouth.

I said 'I think you're under the impression', which means I've given you the opportunity to tell me otherwise...I never said 'Luminal is clearly under the impression...' Sorry if I came across as putting words in your mouth, that wasn't my intention.

When natural selection is removed, beneficial evolution cannot take place, except by sheer randomness (the kind that creations mistakenly refer to in normal evolution).

Since benign and negative mutations occur more often than beneficial mutations, and without natural selection to do the picking, evolution that degrades a species is the natural course.

 

It's too early to tell the affects this will have on our adaption, modern medicine has been around for a fraction of the time relative to evolution time scales. Here's an article on the evolution of our brain which you may find interesting...may come back to this, just about to leave work...

 

http://www.nytimes.com/2005/09/08/science/08cnd-brain.html

[iNow]

We are still evolving, natural selection is still occurring, there are just a different set of selection pressures. As stated above, the subjective "improvement" or "regression" experienced by future generations is not a determining factor.

 

Selection happens when copulation happens and an offspring is born. Natural selection is always happening, but again, what is selected for or against "in developed countries" is what you are truly discussing here.

[Luminal]

We are still evolving, natural selection is still occurring, there are just a different set of selection pressures. As stated above, the subjective "improvement" or "regression" experienced by future generations is not a determining factor.

 

Selection happens when copulation happens and an offspring is born. Natural selection is always happening, but again, what is selected for or against "in developed countries" is what you are truly discussing here.

 

Natural selection takes place after the child-rearing age in the vast majority of the population in developed countries.

 

There are not a "different set of selection pressures"; most of the selection pressures are simply gone.

 

The few examples I can think of in which selection pressures still exist would include drunk driving and general foolish behavior as a teenager; infectious and/or terminal diseases that kill children; depression leading to suicide in youth; and perhaps a few more.

 

However, the overwhelming majority of humans do not die in adolescence, and most do not die during the child-rearing ages either. Most humans die after the age of 60.

 

To be specific, natural selection and evolution have parted ways in developed countries. Perhaps both still exist, but they are not greatly affecting one another.

[iNow]

Natural selection takes place after the child-rearing age in the vast majority of the population in developed countries.

No. Natural selection occurs when offspring are had. Whatever led to their successful birth was selected (or conversely, whatever prevented them from being killed or made sterile prior to reproducing was selected). Simple really. The selection will then continue if those offspring are able to successfully procreate.

 

There are not a "different set of selection pressures"; most of the selection pressures are simply gone.

This is also an incorrect statement. If you claim otherwise, please support your assertion.

 

However, the overwhelming majority of humans do not die in adolescence, and most do not die during the child-rearing ages either. Most humans die after the age of 60.

That is correct, but does not support your point that natural selection no longer occurs in "developed countries."

 

To be specific, natural selection and evolution have parted ways in developed countries. Perhaps both still exist, but they are not greatly affecting one another.

Repeating yourself does not make your comment any more accurate or valid. Natural selection is always occurring, and definitely exists. Evolution and natural selection are interconnected at a most profound level, and, as mentioned above, there are just different selection pressures in different regions and epochs.

 

Just because we don't die as often from starvation and disease "in developed countries," nor as often as we did in our ancestral past, you cannot in any valid way claim that natural selection is not occurring. We have different pressures, like cancer, or automobile traffic, or electrocution, or choking, or ad infinitum... but selection itself still occurs.

[Luminal]

Before rebutting any points, I do want to make clear that I am not claiming natural selection or evolution does not occur, yet the role of natural selection is extremely small in evolution upon a postindustrial, developed society. Without strong selection pressures, evolution is freed to drift in any direction, even right into the jaws of extinction.

 

No. Natural selection occurs when offspring are had. Whatever led to their successful birth was selected (or conversely, whatever prevented them from being killed or made sterile prior to reproducing was selected). Simple really. The selection will then continue if those offspring are able to successfully procreate.

 

The best way to understand what I am saying is through an example.

 

In a preindustrial society, a person is born with a severe lung defect (a deleted gene, say) and cannot contribute to society in any meaningful way. A harsh winter falls upon this society, and many die. The weakest are the first to go, including the individual with the poor respiration.

 

In our modern society, this person could live a long and prosperous life, be taken very good care of, and even make a living in a non-manual labor job that did not stress his breathing. He could pass his genes on many times to children.

 

Please tell me how natural selection acted in the second situation to the same degree as the first. Remember (if you read my post), I am not saying natural selection does not exist whatsoever (obviously there will always be factors that even humans cannot avoid), yet that it plays a role very rarely in a society in which we take care of our sick, disabled and poor.

 

This is also an incorrect statement. If you claim otherwise, please support your assertion.

 

How can you possibly dispute that statement? Are you telling me that most selection pressures that actively affect the passing of genes still remain in modern society from early in our evolution? Some will always remain, but the average age of death is well beyond reproductive years and usually occurs from poor cardiovascular health or cancer, not from being preyed upon, freezing to death, or starvation.

 

Simply put, selection pressures that actively affect the transfer of genes to offspring have diminished drastically and very little has come to take their place (perhaps car wrecks are an example of a replacement, but they account for less than 3% of the deaths in developed countries).

 

That is correct, but does not support your point that natural selection no longer occurs in "developed countries."

 

First, I did not say it no longer occurred, but that it usually occurs well beyond the point of having any effect upon evolution. If I'm addicted to horribly unhealthy food, yet have 12 children (whom I also feed unhealthy food) and die from a heart attack when I'm 58, how did natural selection play a role in evolution? Please explain.

 

 

Repeating yourself does not make your comment any more accurate or valid. Natural selection is always occurring, and definitely exists. Evolution and natural selection are interconnected at a most profound level, and, as mentioned above, there are just different selection pressures in different regions and epochs.

 

There are different selection pressures, of course, but the role of natural selection is nearly non-existent in evolution if people who would normally perish before reproduction are sustained indefinently by technology and pass on harmful genes to numerous offspring.

 

Just because we don't die as often from starvation and disease "in developed countries," nor as often as we did in our ancestral past, you cannot in any valid way claim that natural selection is not occurring. We have different pressures, like cancer, or automobile traffic, or electrocution, or choking, or ad infinitum... but selection itself still occurs.

 

Again, I did not say natural selection is not occurring; its role is greatly diminished in evolution. And if natural selection is not strong enough to weed out harmful genes before an organism has a chance to pass them on, then evolution as a whole cannot benefit a species on the long term, unless sheer luck intervenes (or genetic engineering, that is).

[iNow]

Before rebutting any points, I do want to make clear that I am not claiming natural selection or evolution does not occur, yet the role of natural selection is extremely small in evolution upon a postindustrial, developed society.

 

<...>

 

Remember (if you read my post), I am not saying natural selection does not exist whatsoever (obviously there will always be factors that even humans cannot avoid), yet that it plays a role very rarely in a society in which we take care of our sick, disabled and poor.

 

<...>

 

First, I did not say it no longer occurred, but that it usually occurs well beyond the point of having any effect upon evolution.

 

<...>

 

Again, I did not say natural selection is not occurring; its role is greatly diminished in evolution.

 

 

Clarification:

 

Thread title:

Humans have stopped Evolving in Developed Countries.

 

 

Opening post:

Thus, evolution does not occur and people keep on loving high fat food and being addicted to nicotine.

 

 

Post #7:

To respond to both, natural selection, the fuel of evolution, is missing in developed countries. Humans are not "adapting to change."

 

 

Post #15:

To be specific, natural selection and evolution have parted ways in developed countries. Perhaps both still exist, but they are not greatly affecting one another.

 

 

 

 

I hope you can understand my confusion.

 

 

 

 

 

Please tell me how natural selection acted in the second situation to the same degree as the first.

You're moving the goal posts, and you are essentially agreeing with everything I said. The selection pressures have changed. You were not saying "people who are sick in developed countries have a better chance at surviving and passing on their genes to offspring than those who do not live in developed countries." You were saying, "Humans have stopped evolving in developed countries." This is a HUGE difference. The first one is correct, the second one is wrong.

 

 

How can you possibly dispute that statement? Are you telling me that most selection pressures that actively affect the passing of genes still remain in modern society from early in our evolution? Some will always remain, but the average age of death is well beyond reproductive years and usually occurs from poor cardiovascular health or cancer, not from being preyed upon, freezing to death, or starvation.

It's quite easy. You stated: "There are not a "different set of selection pressures"; most of the selection pressures are simply gone. " To suggest that most selection pressures are simply gone is simply wrong. Further, above, you've now agreed with me that selection pressures have simply changed. Which is it? You're being very inconsistent.

 

 

 

If I'm addicted to horribly unhealthy food, yet have 12 children (whom I also feed unhealthy food) and die from a heart attack when I'm 58, how did natural selection play a role in evolution? Please explain.

Whatever traits allowed you, despite being addicted to horribly unhealthy food, to reproduce before dying of your heart attack were selected. Selection still occured because you reproduced before dying (as opposed to, say, someone who ate horribly unhealthy food and died of a heart attack BEFORE reproducing). Is this clear?

 

 

What I sense happening here is that most of our understandings of natural selection are quite different from yours. This exact point was presented by other posters well before I even joined this thread. That's perhaps something to consider.

 

Ask yourself if you are really using the correct terms to describe your thoughts. Is it really our fault for challenging what you say if you're not saying it correctly or consistently?

 

 

If I may, here's what I think you are trying to present:

 

Humans living in modern developed countries have access to technology and medicine which can significantly increase lifespan, and cure illness which was previously terminal. Many life events and ailments that would have killed us in our ancestral past (or still kill in less developed countries where the same technology and medicine is not as widely available) no longer have the same negative impact.

 

For these reasons, as a general rule we are passing on more negative traits to future generations since the "weak" ones of the group have a greater chance of surviving and are being "weeded out" at a much slower rate than in non-developed countries and our ancestral past. The pressures that prevented successful reproduction in our ancestors were several orders of magnitude higher in frequency than the pressures preventing successful reproduction in modern developed societies, and the impact on us all as a modern culture are profound.

 

Is this about accurate?

[ydoaPs]

At looking at the definitions in several dictionaries, it would seem "evolve" tends to mean progressive changes in other fields, yet in biology it tends to be intentionally vague in regards to progress.

The dictionary is NOT a technical resource.

[Sisyphus]

To break this down as simply as possible:

 

To see where a species is evolving, look at what traits correlate to a greater likelihood of producing more surviving offspring.

 

Those traits, no matter what they are, are "positive" from an evolutionary standpoint and in that species' particular environment.

 

This includes humans.

 

It STILL includes humans, and humans are still evolving.

 

We as a society have come to deem certain traits, like high intelligence, as "positive."

 

Note that societally-deemed "positive" and evolutionarily "positive" need not be the same.

 

The argument can be made that the current course of evolution, driven by a recently radically altered environment (technology, etc,), has shifted such that evolutionarily positive traits and perceived positive traits are now very often in opposition, when previously, in a "natural" environment, they corresponded very closely. As a result, most us probably wouldn't like where the human species is currently headed.

 

Can we all agree on those statements, at least?

[Luminal]

That is correct, iNow.

 

At any point I used the word "evolution" at the beginning of this thread, assume I was referring to "beneficial evolution" on the long term.

 

You must understand my confusion with the terminology considering the word "evolve" by itself has clear implications of progress (or at least non-negative change) when used in normal conversation. Hence why the word "devolve" is used to describe the reverse of the process.

 

Anyway, you summed up my point quite well.

 

Without strong selection pressure, negative mutations are free to be passed on rampantly. Eventually, either larger scale natural selection will step in and slow down our species or genetic engineering will repair our damaged genes.

[ydoaPs]

You must understand my confusion with the terminology considering the word "evolve" by itself has clear implications of progress (or at least non-negative change) when used in normal conversation

Who would have assumed the technical definition of a science related word on a science forum?

[Luminal]

 

We as a society have come to deem certain traits, like high intelligence, as "positive."

 

Note that societally-deemed "positive" and evolutionarily "positive" need not be the same.

 

I believe high intelligence is greatly favored under normal natural selection, not simply by society. Intelligence can enable a human with a tool (like a gun) to kill other animals ten times their mass with ease.

 

The problem is, the most intelligent in developed countries aren't necessarily the ones most likely to reproduce. In fact, those that pursue high academic achievement are probably less likely to have a large family due to the demands of obtaining advanced degrees well into his or her 20's (or perhaps even into the 30's). And if they continue their line of work into research, the pressure does not shrink, but grows.

 

And at the same time, the two high school graduates settle down with a $15/hour wage and begin raising a family at the age of 20.

 

Who would have assumed the technical definition of a science related word on a science forum?

 

Well, I would assume it was the same until I was told otherwise.

 

Why assume the word "yes" means "yes" in science? Because you haven't encountered people using it otherwise.

 

Yet I now know better. But I would think it wise for scientists to use words that are most similar to their normal meaning. Perhaps Evolution should be called "Genetic Change" or some such.

[Sisyphus]

I believe high intelligence is greatly favored under normal natural selection

 

Then you're wrong. What is favored under natural selection is what correlates with higher numbers of viable offspring. That's it. Sometimes higher intelligence is favored, and sometimes it isn't. If it always was, every single species would steadily and rapidly get smarter and smarter. This doesn't happen.

 

For some idea of why this is so, think about what humans pay for their intelligence: our big brains are huge nutrient sponges, and they take incredibly long to develop, resulting in by far the longest period of childhood dependency, among other things. If being dumber means we can have kids sooner and more often, and the lack of intelligence doesn't hurt their survival chances much, then THAT is favored by natural selection.

[Luminal]

Then you're wrong. What is favored under natural selection is what correlates with higher numbers of viable offspring. That's it. Sometimes higher intelligence is favored, and sometimes it isn't. If it always was, every single species would steadily and rapidly get smarter and smarter. This doesn't happen.

 

For some idea of why this is so, think about what humans pay for their intelligence: our big brains are huge nutrient sponges, and they take incredibly long to develop, resulting in by far the longest period of childhood dependency, among other things. If being dumber means we can have kids sooner and more often, and the lack of intelligence doesn't hurt their survival chances much, then THAT is favored by natural selection.

 

Well, intelligence has sure given humans a survival advantage, has it not? So much survival that at this rate humans might cause every other species on earth to go extinct if our population keeps increasing. I'd say that was a successful species.

 

As for why not all species evolve toward greater intelligence, I couldn't honestly say.

 

Obviously, the "price" of our big brains is easily paid back hundreds of times with the advantages it gives us to produce food, defend against predators, work together in very large groups (up to nations), make tools, and so on.

 

So, the price of intelligence cannot be the only reason other species do not evolve toward it.

 

Do you have any suggestions?

 

It might have to do with the emergent nature of brain structures, in which a larger brain or more neurons do not correlate to greater intelligence unless every other structure meshes perfectly with the changes. This makes for an even greater challenge for it to evolve.