How Evolution Really Works

[George S]

By culling. By killing. By failing to reproduce.

Will the human race evolve into a different race? A group of our descendants so far in the future that we couldn't have offspring with them? Groups of descendants of different lines unable to interbreed and produce fertile offspring? -- two races?


There are harsh conditions where the cost of doing it wrong is a life. This is where evolution favoring intelligence happens. This is where saving for the winter happens. Living in the mountains, for example. This same environment favors the strong. Those who can defend the family. Lots of young defenders. And the survivors among those defenders mate selecting for young who like defending family.


There are favorable conditions where the cost of doing it wrong is temporary hunger. This is where "smart enough to pick a fruit off a tree" is the standard and mating is a free-for-all. No need to plan ahead. Take no care for the morrow. Eat, drink, interact socially, have sex. The bonobo is the quintessential example.


Will we eventually evolve into an intelligent species? Time will tell.

 

[skepticalbip]

There are any number of catastrophes that could eliminate humanity. But if the line isn't extinguished by catastrophe then our descendants five million years from now will likely be as different from us as we are from our ancestors of five million years ago. If there are isolated groups (like if we colonize space or some near catastrophe reason population is reduced and there is no longer contact between continents) then the various groups will follow different evolutionary paths resulting in different species.

 

[rousseau]

By culling. By killing. By failing to reproduce.

Will the human race evolve into a different race? A group of our descendants so far in the future that we couldn't have offspring with them? Groups of descendants of different lines unable to interbreed and produce fertile offspring? -- two races?


There are harsh conditions where the cost of doing it wrong is a life. This is where evolution favoring intelligence happens. This is where saving for the winter happens. Living in the mountains, for example. This same environment favors the strong. Those who can defend the family. Lots of young defenders. And the survivors among those defenders mate selecting for young who like defending family.


There are favorable conditions where the cost of doing it wrong is temporary hunger. This is where "smart enough to pick a fruit off a tree" is the standard and mating is a free-for-all. No need to plan ahead. Take no care for the morrow. Eat, drink, interact socially, have sex. The bonobo is the quintessential example.


Will we eventually evolve into an intelligent species? Time will tell.

What would an 'intelligent' species look like?

 

[bilby]

By culling. By killing. By failing to reproduce.

Will the human race evolve into a different race? A group of our descendants so far in the future that we couldn't have offspring with them? Groups of descendants of different lines unable to interbreed and produce fertile offspring? -- two races?


There are harsh conditions where the cost of doing it wrong is a life. This is where evolution favoring intelligence happens. This is where saving for the winter happens. Living in the mountains, for example. This same environment favors the strong. Those who can defend the family. Lots of young defenders. And the survivors among those defenders mate selecting for young who like defending family.


There are favorable conditions where the cost of doing it wrong is temporary hunger. This is where "smart enough to pick a fruit off a tree" is the standard and mating is a free-for-all. No need to plan ahead. Take no care for the morrow. Eat, drink, interact socially, have sex. The bonobo is the quintessential example.


Will we eventually evolve into an intelligent species? Time will tell.

What would an 'intelligent' species look like?

If you don't own a mirror, you should be able to find a crow to look at.

 

[Nexus]

By culling. By killing. By failing to reproduce.

This is actually the biggest misconception people have about evolution. What you mention here falls under natural selection. The fact you omit sexual selection, genetic drift, mutation, and migration as mechanisms of evolution means your entire premise is flawed.

And natural selection is about out competing over long periods of time. Its not a binary process of death or offspring. If a subpopulation of a species has 3.5 offspring on average and another only has 2.3 in the same environment the 3.5 group will be the "strongest" in terms of evolution through natural selection.

 

[rousseau]

What would an 'intelligent' species look like?

If you don't own a mirror, you should be able to find a crow to look at.

The reason I ask is because George S suggested we aren't intelligent.

It's also something I think about a lot. We've given ourselves the label, but what does it actually mean?

If being intelligent means we have strong working memory and can manipulate information, then we are.

On average, though, I don't think people do that particularly well, and I don't think many people store a lot of information with which to help them manipulate other information.

So calling ourselves 'intelligent' probably just happened because we're so distinct from other animals. But whether we actually are is in question.

 

[Valjean]

Our current civilization is selecting for lower intelligence and less physical fitness. Clever ideas spread around the world almost instantly, conferring no specific advantage to the inventor, and there is a negative correlation between education and number of children. nor are disabilities reproductively disadvantageous anymore (I type as I peer through my bifocals).

 

[rousseau]

Our current civilization is selecting for lower intelligence and less physical fitness. Clever ideas spread around the world almost instantly, conferring no specific advantage to the inventor, and there is a negative correlation between education and number of children. nor are disabilities reproductively disadvantageous anymore (I type as I peer through my bifocals).

I wonder if any paper exists that proves at least parts of this. It's not so much that I doubt it, but a claim of this magnitude and relevance is something I'd want to verify so I would *know*... you know?

 

[Valjean]

Our current civilization is selecting for lower intelligence and less physical fitness. Clever ideas spread around the world almost instantly, conferring no specific advantage to the inventor, and there is a negative correlation between education and number of children. nor are disabilities reproductively disadvantageous anymore (I type as I peer through my bifocals).

I wonder if any paper exists that proves at least parts of this. It's not so much that I doubt it, but a claim of this magnitude and relevance is something I'd want to verify so I would *know*... you know?

http://naturalsociety.com/leading-geneticist-human-intelligence-slowly-declining/

 

[bilby]

I wonder if any paper exists that proves at least parts of this. It's not so much that I doubt it, but a claim of this magnitude and relevance is something I'd want to verify so I would *know*... you know?

http://naturalsociety.com/leading-geneticist-human-intelligence-slowly-declining/

That website contains a bewildering array of utter tosh.

It has negative credibility; almost every faddish woo anti-science box is ticked, from the URL that evokes the appeal to nature fallacy, to its links to claims about serious harm from fluoride in drinking water, and that the consumption of HFCS is a cause, not of obesity (which would be questionable), but of stupidity (which, ironically, is stupid).

Everything about that website screams 'Bullshit! Do not believe!' To me. It has more red flags for pseudoscience than a game of 'minefield'.

It is sites like that that are responsible for increasing stupidity. It has little to do with genetics, and much to do with disinformation masquerading as fact.

 

[ronburgundy]

Our current civilization is selecting for lower intelligence and less physical fitness. Clever ideas spread around the world almost instantly, conferring no specific advantage to the inventor, and there is a negative correlation between education and number of children. nor are disabilities reproductively disadvantageous anymore (I type as I peer through my bifocals).

I wonder if any paper exists that proves at least parts of this. It's not so much that I doubt it, but a claim of this magnitude and relevance is something I'd want to verify so I would *know*... you know?

The key to meaningful data on the topic is large samples, women old enough to have had most or all of their kids, and examing the relationship within country and within gender and within racial group, since that makes IQ and fertility practices more an apples to apple comparison, reducing the number of confounding variables.

The two studies I could readily find that meet these criteria show highly similar results where within both groups of white and black women, those with IQs below 100 had about .5 kids more than women above 100 IQ.

The first is a study in 1982 study with 10,000 people aged 25-34.
The fertility rates of women with below 100 IQ versus those above 100 IQ were 1.7 verus 1.3 among white women, and 2.1 versus 1.5 among black women.
IOW, the difference in fertility rates was greater depending on IQ than the fertility difference between races.


A similar result was found in this 2010 study measuring fertility rates at ages 39-47.
The fertility rates of women with below 100 IQ versus those above 100 IQ were 2.2 verus 1.8 among white women, and 2.3 versus 1.5 among black women.

The higher fertility rate among white women in this study than the prior one makes sense, since all of these women were past common reproductive age. Black women tend to have kids while younger, so their rate wasn't much higher in this study than the prior study.

Here is the main conclusion of the latter study.

Using what is arguably the best data set currently available, the results confirm previous reports (Lynn and van Court, 2004, Retherford and Sewell, 1988, Udry, 1978, van Court and Bean, 1985, Vining, 1982, Vining, 1986 and Vining, 1995) about a negative relationship between IQ and number of children in the United States during the last third of the 20th century. Thus the existence of IQ dysgenics can be considered firmly established for this time and place.

They also do a bunch of complex path model analysis to test various mediating mechanisms for the relationship, finding that attending college is the greatest mediating mechanism, namely women with higher IQ attend college and get careers which delays having kids resulting in fewer kids overall.

His other claim is just rather obvious on its face, so much so that no one would have bothered to empirically verify it. The products of intelligence and their utility is readily available to everyone who can access the internet. The person advantage to those with the minds that created this knowledge is largely non-existent. Also, the modern workplace contributes to this further, where people with wealth acquired via heavily on luck and unethical acts (not intellect) pay to reap most of the fitness benefits of other people's intellect. This is one example of the more general fact that civilized society, especially democracy and collectively shared resources and safety nets greatly reduces any relative advantage over others gained by one's own genetically impacted traits. Our collective aggregate traits more collectively impact us all. Of course this isn't 100%, but far moreso than throughout most of the centuries of past human evolution where people only benefited from the intellect (and other adaptive traits) of those in their own small kinship clan, creating a far tighter tethering of one's genes to one's survival and reproduction success.

But if the line isn't extinguished by catastrophe then our descendants five million years from now will likely be as different from us as we are from our ancestors of five million years ago.

This is incorrect, due to the reasons above.
The rate of human evolution is a product of differential survival and reproduction rates of people, due to their genetic and thus phenotypic differences. By decoupling genetic variance between people from their survival and reproductive probabilities, civilization has greatly slowed down evolutionary change. Also, humans just are not migrating like they used to, where people entered into a completely novel climate, ecosystem, and geography for the first time without any stores of cultural knowledge, just playing roulette of trial and error to see who survives and what works.

Catastrophies can of course produce major leaps in change, and one that destroyed civilization and social contract would rev the evolutionary engine back into full speed. But the reality is that such catastrophe's are no more likely in the future than the past and actually we are better able to reduce their impact now than the past. Thus, odds are high that we will evolve far less over the next 1 million years than the previous million.

 

[Trausti]

http://naturalsociety.com/leading-geneticist-human-intelligence-slowly-declining/

That website contains a bewildering array of utter tosh.

It has negative credibility; almost every faddish woo anti-science box is ticked, from the URL that evokes the appeal to nature fallacy, to its links to claims about serious harm from fluoride in drinking water, and that the consumption of HFCS is a cause, not of obesity (which would be questionable), but of stupidity (which, ironically, is stupid).

Everything about that website screams 'Bullshit! Do not believe!' To me. It has more red flags for pseudoscience than a game of 'minefield'.

It is sites like that that are responsible for increasing stupidity. It has little to do with genetics, and much to do with disinformation masquerading as fact.

Maybe seyorni just picked the first search hit. But the idea that intelligence is declining should hardly be controversial. The World, and in particular the West, has turned natural selection on its head. Before, reproductive success was associated with power, wealth, and skill. Hence, only this group could afford to have large families. Up to 80% of intelligence is heritable:http://www.the-scientist.com/?articles.view/articleNo/31016/title/Heritability-of-Intelligence

Today, however, with generous welfare benefits and a modern culture which seemingly devalues personal responsibility, more educated and successful people have fewer children while those on the lower end have higher fecundity. This, of course, is facilitated by modern sanitation and medicine. Looked at globally, women in countries with lower national IQ have significantly more children than their counterparts in higher IQ countries. Consequently, the average IQ would trend downward and another civilization collapse, this time of global impact, is probable. (Though we'll all likely be dead before that happens.)

http://www.dailymail.co.uk/sciencetech/article-2730791/Are-STUPID-Britons-people-IQ-decline.html

http://uhaweb.hartford.edu/BRBAKER/

 

[skepticalbip]

But if the line isn't extinguished by catastrophe then our descendants five million years from now will likely be as different from us as we are from our ancestors of five million years ago.

This is incorrect, due to the reasons above.
The rate of human evolution is a product of differential survival and reproduction rates of people, due to their genetic and thus phenotypic differences. By decoupling genetic variance between people from their survival and reproductive probabilities, civilization has greatly slowed down evolutionary change. Also, humans just are not migrating like they used to, where people entered into a completely novel climate, ecosystem, and geography for the first time without any stores of cultural knowledge, just playing roulette of trial and error to see who survives and what works.

Catastrophies can of course produce major leaps in change, and one that destroyed civilization and social contract would rev the evolutionary engine back into full speed. But the reality is that such catastrophe's are no more likely in the future than the past and actually we are better able to reduce their impact now than the past. Thus, odds are high that we will evolve far less over the next 1 million years than the previous million.

You are omitting a hell of a lot that affects the direction of evolution. Genetic drift, changing sexual preferences, climate changes, isolation, etc., etc. We have no way of knowing what our evolutionary future has in store. In fact our current isolation from the need to hunt and forage or isolation of the need to physically defend ourselves to survive, etc. (very recent in evolutionary time) may be a more powerful evolutionary force than the migration out of Africa.

 

[bilby]

That website contains a bewildering array of utter tosh.

It has negative credibility; almost every faddish woo anti-science box is ticked, from the URL that evokes the appeal to nature fallacy, to its links to claims about serious harm from fluoride in drinking water, and that the consumption of HFCS is a cause, not of obesity (which would be questionable), but of stupidity (which, ironically, is stupid).

Everything about that website screams 'Bullshit! Do not believe!' To me. It has more red flags for pseudoscience than a game of 'minefield'.

It is sites like that that are responsible for increasing stupidity. It has little to do with genetics, and much to do with disinformation masquerading as fact.

Maybe seyorni just picked the first search hit. But the idea that intelligence is declining should hardly be controversial. The World, and in particular the West, has turned natural selection on its head. Before, reproductive success was associated with power, wealth, and skill. Hence, only this group could afford to have large families. Up to 80% of intelligence is heritable:http://www.the-scientist.com/?articles.view/articleNo/31016/title/Heritability-of-Intelligence

Today, however, with generous welfare benefits and a modern culture which seemingly devalues personal responsibility, more educated and successful people have fewer children while those on the lower end have higher fecundity. This, of course, is facilitated by modern sanitation and medicine. Looked at globally, women in countries with lower national IQ have significantly more children than their counterparts in higher IQ countries. Consequently, the average IQ would trend downward and another civilization collapse, this time of global impact, is probable. (Though we'll all likely be dead before that happens.)

http://www.dailymail.co.uk/sciencetech/article-2730791/Are-STUPID-Britons-people-IQ-decline.html

http://uhaweb.hartford.edu/BRBAKER/

That's a lovely hypothesis you've got there. It would be a shame if someone were to test it.

It's not at all clear that IQ can be used to measure intelligence in the way that graph suggests; but even if it could, all the named countries show an increase in 'average IQ' (whatever the fuck that is); so quite where the steep down-slope of the dark blue line originates is unclear - is that supposed to represent the UK; the world; the local mental asylum; the Daily Mail offices; or what?

The fact is that the number of competent people worldwide in every technological field has been growing for a few hundred years, and the trend shows no sign of abating, so clearly there is more going on that that simplistic hypothesis would suggest.

The only thing in your post that even vaguely supports the hypothesis that people are becoming less intelligent is the ongoing trend of people using the Daily Mail as though it were a reliable or valuable source of information. To do that is truly a sign of low intelligence.

 

[ronburgundy]

This is incorrect, due to the reasons above.
The rate of human evolution is a product of differential survival and reproduction rates of people, due to their genetic and thus phenotypic differences. By decoupling genetic variance between people from their survival and reproductive probabilities, civilization has greatly slowed down evolutionary change. Also, humans just are not migrating like they used to, where people entered into a completely novel climate, ecosystem, and geography for the first time without any stores of cultural knowledge, just playing roulette of trial and error to see who survives and what works.

Catastrophies can of course produce major leaps in change, and one that destroyed civilization and social contract would rev the evolutionary engine back into full speed. But the reality is that such catastrophe's are no more likely in the future than the past and actually we are better able to reduce their impact now than the past. Thus, odds are high that we will evolve far less over the next 1 million years than the previous million.

You are omitting a hell of a lot that affects the direction of evolution. Genetic drift, changing sexual preferences, climate changes, isolation, etc., etc. We have no way of knowing what our evolutionary future has in store. In fact our current isolation from the need to hunt and forage or isolation of the need to physically defend ourselves to survive, etc. (very recent in evolutionary time) may be a more powerful evolutionary force than the migration out of Africa.

I'm not omitting those factors. Those factors all have less impact now than the past and their impact will continue to lessen barring a world wide near extinction event.
Genetic drift has much smaller effects on large populations and populations that are not isolated from one another. Populations are much larger and much less isolated from each other now, thus, genetic drift will have much milder and slower effects on evolution now and in the future than it did many thousands of years ago.

"Isolation" is evolutionary terms only has its impact because it refers to sub-groups of the same species being isolated from each other and thus experiencing highly different selection pressures. The key to evolution is that members of a species reproduce at different rates due to how their variable genetic traits causally determine their reproduction in their environment. Anything that reduces the direct causal impact of one's own genes on one's own reproduction relative to other people is going to undercut the rate of evolution. Being isolated in an environment with different selection pressures than other people experience is one factor. But modern tech and inter-regional travel and trade make selection pressures far more similar between regions than in the past. IOW, unless some catastrophe wipes out all cultural and tech advances, there will be far less human reproductive isolation in the future than the past. The fact that all humans are more "isolated' from personally getting their own food and protecting themselves from threats is among the things that makes us far less isolated from each other in terms of selection pressures, which is what matters for evolution. Instead of each persons' survival depending on their own hunting and survival skills, everyone depends upon the aggregate and collective skills of millions of people and even the whole human race, given international aid. That means that most genetic variance today does not influence variance in "fitness" and in fact their is much less variance in fitness, because survival is more collectively determined. Yes, the change in how we survive changes our evolutionary course, but the main feature of this change is that it greatly slows the rate of evolutionary change by greatly weakening the impact of genetically determined individual skills on individual reproductive success.

As for climate changes, they only have their impact via impacting relative reproductive success tied to genetic variations. Climate changes that used to wipe out segments of the population don't really do it anymore, because our collective technologies and skills allow us to protect the "unfit" from changes that would have killed them centuries ago. The things most likely to spark evolutionary change now are drastic environment shifts that just wipe out large portions of the human race, without any ability for societies to collectively protect and carry the weight for those less suited to the change. But there are fewer things now that could do that than in the past, because our collectively abilities to prevent them from doing so are greater, plus our socialized willingness to do so is greater.

Just imagine many modern disasters and how much more impact on relative survival of people with differing genetic traits that they would have had 200,000 years ago.
When a major drought occurs in California, what % of the people there die as a direct result? Are the people most affected of a particular genetic makeup? In the past, a large % of the local population would die and one's personal traits directly linked to that environmental feature would determine survival. That is no longer true.

Finally, think about the relative fertility rates between members of the same society? Differences is those rates heavily determine evolutionary change and rates of change. Those rates are far less variable now than previously, less variable between individuals at a given time and less variable over time due to environmental impacts. 200,000 years ago in small clans, you would have women ranging from 0 to 20 kids and it was linked to genetic traits, and an even wider range for males. Today, in most large societies, the 95% of the population falls in the 0-4 range.

 

[ronburgundy]

Maybe seyorni just picked the first search hit. But the idea that intelligence is declining should hardly be controversial. The World, and in particular the West, has turned natural selection on its head. Before, reproductive success was associated with power, wealth, and skill. Hence, only this group could afford to have large families. Up to 80% of intelligence is heritable:http://www.the-scientist.com/?articles.view/articleNo/31016/title/Heritability-of-Intelligence

Today, however, with generous welfare benefits and a modern culture which seemingly devalues personal responsibility, more educated and successful people have fewer children while those on the lower end have higher fecundity. This, of course, is facilitated by modern sanitation and medicine. Looked at globally, women in countries with lower national IQ have significantly more children than their counterparts in higher IQ countries. Consequently, the average IQ would trend downward and another civilization collapse, this time of global impact, is probable. (Though we'll all likely be dead before that happens.)

http://www.dailymail.co.uk/sciencetech/article-2730791/Are-STUPID-Britons-people-IQ-decline.html

http://uhaweb.hartford.edu/BRBAKER/

That's a lovely hypothesis you've got there. It would be a shame if someone were to test it.

It's not at all clear that IQ can be used to measure intelligence in the way that graph suggests; but even if it could, all the named countries show an increase in 'average IQ' (whatever the fuck that is); so quite where the steep down-slope of the dark blue line originates is unclear - is that supposed to represent the UK; the world; the local mental asylum; the Daily Mail offices; or what?

Agreed. It makes not sense that all the countries shown, from North America, to Asia, to Africa trend upward, but the "Avg" trends steeply downward.

The fact is that the number of competent people worldwide in every technological field has been growing for a few hundred years, and the trend shows no sign of abating, so clearly there is more going on that that simplistic hypothesis would suggest.

That confuses intelligence (the ability to acquire knowledge more efficiently) with how much knowledge is acquired, which is a product of amount of training and experience moderated by intelligence. Intelligence has its impact by processing information and experiences. Lack of information means no grist for the mill, so an efficient mill still produces nothing. And a less efficient mill can still produce more if given more grist with which to work.
IOW, there is nothing about the increase in technical competence that contradicts the notion that avg IQ might be declining.

The only thing in your post that even vaguely supports the hypothesis that people are becoming less intelligent is the ongoing trend of people using the Daily Mail as though it were a reliable or valuable source of information. To do that is truly a sign of low intelligence.

What about using a comic strip that makes claims about what is true and false without any reference to any data at all?

I linked to 2 large scale studies looking at fertility rate differences for low and high IQ women, controlling for race. One showed that attending college was the best explanatory mechanism for why higher IQ women delay child rearing and wind up having fewer kids.

Even those who ideologically tend to dismiss "intelligence" as a concept, typically acknowledge the fact that whatever it measures is highly predictive of educational success. Here is a CDC study showing a massive, nearly double the rate difference in fertility between high school graduates (2.7 kids) versus college graduates (1.4 kids).
Many factors impact college attendance and graduation, but one of them is the set of cognitive skills tapped by IQ tests which predict High school GPA and graduation, taking honors courses, entry exam scores, college admissions, college gpa, and college graduation.

Women with lower IQ are having significantly more kids, and in today's modern world, they are not less likely to survive to reproduce themselves. Genes are a notable contributor to IQ scores. So, its highly plausible that this differential fertility rate is leading to an effect on average brain biology that impedes the cognitive performance measured by and predicted by IQ tests. However, this does NOT mean that IQ scores or the cognitive performance it measures will decline overall. There are significant non-genetic factors that interact with any genetic ones to determine cognitive performance. IF those factors are improving than could cancel or even outweigh any decline in the genetic traits. For example, brain development in utero and early childhood are impacted by nutrition and cognitive stimulation. IF those are generally improving (and they are), then they would push avg IQ upward against any downward effects due to genetic contributions.

One of the reasons that doomsday prophecies are usually wrong is that even when they are right about the negative trajectory of the one cause they are focused on, the outcome they are talking about is so multiply determined that the other causes are likely to wash out any notable impact of their myopic focus.