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DDE

The human population dynamics thread [Split from Mars Colonization thread]

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On 2/9/2019 at 10:13 PM, tater said:

Regarding power vs pop growth, most estimates show world pop increasing to ~9 billion, then falling off.

World wellbeing is at an all time high, and the trends are in the right direction, and people who are better off have fewer kids.

Oh, I wouldn't be too sure about that...

https://royalsocietypublishing.org/doi/full/10.1098/rspb.2013.2561

Quote

We present a model of the fertility transition as a cultural process acting on new lifestyles associated with fertility. Differences in parental and social influences on the acquisition of these lifestyles result in intergenerational correlations in fertility. We show different scenarios for future population size based on models that disregard intergenerational correlations in fertility, models with fertility correlations and a single lifestyle, and models with fertility correlations and multiple lifestyles. We show that intergenerational fertility correlations will result in an increase in fertility over time. However, present low-fertility levels may persist if the rapid introduction of new cultural lifestyles continues into the future.

Quote

A slightly less well-known but related phenomenon is that the correlation between parent and child fertility has increased from insignificant levels prior to the fertility transition, to moderate and increasing levels in contemporary societies. This correlation may be genetic, cultural or some combination of the two. The increasing intergenerational correlation suggests that cultural or genetic inheritance has become an increasingly significant determinant of fertility.

Quote

Given that variation in fertility has become associated across generations, the basic premises of evolution suggest that the frequency of individuals with relatively more children will increase, and hence the overall level of fertility must also increase (a logical implication recognized by several studies). This raises the possibility that the recent global decline in fertility might be reversed. This reversal will occur regardless of whether intergenerational fertility is the result of cultural or genetic factors, provided intergenerational fertility correlations persist. Researchers have shown that even moderate intergenerational fertility associations could increase population size.

https://jasoncollins.blog/2018/10/11/an-evolutionary-projection-of-global-fertility-and-population-my-new-paper-with-lionel-page-in-evolution-human-behavior/

Quote

One of the most high profile forecasts of fertility and population comes from the United Nations... These projections contain an important fertility assumption. For countries that have undergone the demographic transition to low fertility, the assumption is that their fertility rate will oscillate around a long-term mean. While there has been some debate around whether this long-term mean would be the replacement rate or lower, the (almost theory-free) assumption of oscillation around a long-term level dominates the forecasts.

Quote

And here are a few charts showing the simulation results: grey is the base United Nations simulation, black the evolutionary simulations, the dashed lines the 90% confidence intervals.

Spoiler

 

900pop.jpg?w=620&h=620

908pop.jpg?w=620&h=620

 

 

 

Edited by DDE

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The median age of population makes sense, neither the average age, nor the instantaneous value of fertility.

https://en.wikipedia.org/wiki/List_of_countries_by_median_age

(Rearrange by clicking on "Total (year)")

Where the median age is < 30..35 (when humans usually make additional humans), most of people will have a pair babies in a decade.

World average of median age is ~30.

So, the world population itself at the moment tends to stop expanding, but local population of some regions tend to overwhelm the world statistics and grow locally.

(Like on the charts mentioned by @DDE)

Edited by kerbiloid

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The fertility rate is ~2.5 (world average) right now, but has been on a steady downward tread for decades. It was 4.97 in the '50s. It's headed towards a value under 2. and not every pair of new humans makes it to reproductive age.

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10 minutes ago, tater said:

The fertility rate is ~2.5 (world average) right now, but has been on a steady downward tread for decades. It was 4.97 in the '50s. It's headed towards a value under 2. and not every pair of new humans makes it to reproductive age.

"for decades" = "for a couple of generations"

https://en.wikipedia.org/wiki/Population_pyramid#Youth_bulge_phenomenon

So, it's just the calm before the storm. 

Edited by kerbiloid

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Nope. I quoted fertility rate. That accounts for the age distribution, because it only counts childbearing years. The replacement rate is 2.3. The world is barely above replacement rate now.

Poor countries have higher fertility rates, affluence = lower fertility rates (along with the empowerment of women, which of course cripples certain parts of the world where they are defined by magic as lesser beings). To the extent the global trends improve the lives of people in general, rates should continue to drop. the % of people who live in extreme poverty has literally dropped by an order of magnitude in the last 100 years, all while the population was growing massively. More people, and in less poverty.

It's also fair to note that the replacement rate is substantially above 2.3 in countries where the birth rate is really high for a number of reasons.

I don't buy carrying capacity arguments for space colonies, but if resource extraction and manufacturing in space can become a thing, that certainly can't hurt things.

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51 minutes ago, tater said:

I quoted fertility rate.

Fertility rate is highly volatile.
When your population has median age over 30, only some of them will make children in close future.
When your population is under 20, most of them will do it, nevertheless how great is fertility rate at the moment. They just have no choice.

51 minutes ago, tater said:

To the extent the global trends improve the lives of people in general, rates should continue to drop.

1. In limit. When they have unlimited supplies. The supplies are not unlimited. Especially, water.

2. Many cultures prefer local conservation even by the cost of economical success. You can always take the richer neighbor tribe's goods if you have a lot of more hungry people.
They motivate their members stay hungry but angry.

3. The goods are not distributed uniformly between the society members. And the tendention is pessimistic.
And this is not about the rich capitalists. In a so-called "traditional" society of poor regions all goods belong to the family, and the head of the family distributes them.
Even bed linen. The wives of the sons every evening take it from the big house and carry to the personal huts, then every morning return it back to the big house (where the chief with his wife lives).
And if you suggest them to "improve the life" by the cost of the lifestyle of ancestors, the most probable answer would be a stone. (Stones, because a village.)
Then the chief will accumulate the money to arm the men of the family against the neighbor family. They just measure the "quality of life" in another units, the big family is the first.

4. The mass production of a good makes it cheaper, so several largest manufacturers and resellers inevitably occupy the market.
This inevitably eliminates small and medium manufacturers (the big ones sell same goods cheaper, give a warranty, and you have a less risk if buy from them, not from a "Local Pinkie-Winkie Workshop").
This eliminates and concentrates in biggest cities the places where you really can apply your knowledge to raise your quality of life.
So, the education helps here, but just while the industry is not overconcentrated in several hands.
Then even in the rich and industrially developed US you have 80% of people working in so-called "service sector" (i.e. manufacturing no goods) and iirc 4% of farmers feeding others and still having a lot of excessive food to export.
This means, that in the nearest future, when the concentration will be finished, and the industry, the office, and the road traffic will get automated, most of people will just have no place to apply their knowledge except just for fun (like we do on this forum, lol).
This will limit the influenceof the education, so the eucation is not a panaceia at all.

51 minutes ago, tater said:

the % of people who live in extreme poverty has literally dropped by an order of magnitude in the last 100 years

People in extreme poverty rob each other. People enough rich to rob the neighbors are attacking the neighbors. So, this is a counter-proof.

***

But anyway extraterrestrial settlements will not solve any economical or demographic problems at all, just because they will take much more time that the mundane problems will give.

Edited by kerbiloid

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6 hours ago, kerbiloid said:

So, the world population itself at the moment tends to stop expanding, but local population of some regions tend to overwhelm the world statistics and grow locally.

Oh, it's worse. Even the currently declining populations are likely to be propelled upwards by a fecund minority.

And I'm not talking about immigrants from less developed societies.

5 hours ago, tater said:

affluence = lower fertility rates

No, as my citations show, to a certain slice of the population. The theory goes that that slice didn't use to stand out because having many kids was useful. It's not now, but this same slice of population keeps breeding.

And simple Darwinism means they'll form greater and greater share of the population.

5 hours ago, kerbiloid said:

This means, that in the nearest future, when the concentration will be finished, and the industry, the office, and the road traffic will get automated

And this is where we arrive to the more terrifying part of the prediction.

Fertility correlates negatively with IQ. IQ is also significantly heritable.

Which means that this growing slice of the population is also of below-average intelligence, which will create a draw on the human capital of developed nations.

So technological development will likely hit a major snag just when human resources become more plentiful, and cheaper.

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13 minutes ago, DDE said:

And this is where we arrive to the more terrifying part of the prediction.
this growing slice of the population is also of below-average intelligence

Terrifying? No way! They will have no need to worry about LES for 100.

 

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1 hour ago, DDE said:

Fertility correlates negatively with IQ. IQ is also significantly heritable.

Which means that this growing slice of the population is also of below-average intelligence, which will create a draw on the human capital of developed nations.

While I agree that IQ is partly influenced by the complex interaction of over 500 genes (the actual mechanisms are not well understood at this time) external factors also seem to be significant. 

A lot of the material I am reading on the subject is highly controversial and may be biased by testing that concentrates too much on either; crystalized IQ (defined as the ability to use learned knowledge and experience), fluid IQ (defined as the ability to solve new problems, use logic in new situations, and identify patterns) or spatial IQ (spatial judgement and the ability to visualise information to solve problems) to determine Fullscale IQ (overall IQ).

While it is true that the Flynn Effect seems to be reaching a plateau, some researchers argue that this is due to saturation of education, health, 'cultural loading', nutritional values, new technology and global connectivity in the developed world (Flynn only used data from; Australia, Austria, Belgium, Brazil, Britain, Canada, China, Denmark, East Germany, France,  Israel, Japan,  Netherlands, New Zealand, Northern Ireland, Norway, Sweden, Switzerland, United States of America, and West Germany Flynn, 1994), the actual global rate is likely continuing on an upward trajectory when these additional factors and the developing world are taken the into account.

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Smarter people tend to have fewer kids, I was not suggesting that affluence drives IQ higher—that said, it likely maximizes available IQ (which is quite heritable, contrary to blank-slaters).

Ie: You can be genetically predisposed to be quite tall, but end up shorter because of malnutrition—if you are predisposed genetically to being shorter, while a good diet can maximize your height, it will not exceed what your genes allow. The same is true with IQ and poverty (you could have an average IQ via genetics, and be lower because of your environment). There's a guy doing machine learning on human DNA data, and you can give him your DNA, and he can tell you your height within a cm or 2. He only has educational achievement data linked to DNA, so it's much more rough on predicting that with your DNA, but if he had a large dataset with IQ and DNA for individuals, he says he could look at someone's DNA, and predict their IQ within 10 points or so.

PS—I forgot why this was in the Mars Colonization thread, lol. Because you'd have to be an idiot to want to move to Mars? ;)

 

On topic, the Zubrin talk on The Space Show was pretty interesting. His meeting with Elon Musk made me realize that Musk is actually serious about this Mars stuff. I tend to forget as SpaceX "gets things done" closer to home, but Zubrin said that Boca Chica is a "shipyard" and that Musk said he wants to build 2 Starships a week.

He said at the end that the Mars Society has a contest for designing a million person Mars colony anyone can enter.

https://www.marssociety.org/news/2020/02/11/mars-city-state-design-competition-announced/

 

Last year's winners (smaller colony of 1000 people):

https://www.marssociety.org/news/2019/10/28/mars-colony-design-contest-winners/

Edited by tater

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7 minutes ago, tater said:

he says he could look at someone's DNA, and predict their IQ within 10 points or so.

Very interesting, where can I learn more about this guy's work?

Edited by sh1pman

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1 minute ago, sh1pman said:

Very interesting, where can I learn more about this guy's work?

Think it was on Lex Fridman's AI podcast last year.

 

He's also on youtube.

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1 minute ago, tater said:

Think it was on Lex Fridman's AI podcast last year.

 

He's also on youtube.

Thanks.

 

Wow, that's a lot of podcasts to dig through.

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OK, think it was Stephen Hsu (the ML guy). Might not have been Lex's podcast, might have been radiolab.

The short answer is that since it's not A gene, but a complex arrangement of thousands of genes, no human could have ever figured it out. Set ML on it, and see what happens. They can tell that a fertilized egg has a constellation of genes that maps to very bad educational outcomes, and simply not select those eggs for people doing that to have kids (because the old-fashioned way isn't working for them ;) ). He said ethically, he would not select eggs for high intelligence, but it's just a matter of time before someone offers this.

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1 hour ago, StrandedonEarth said:

Gattaca is getting closer...

Not a bad movie, imo.

3 hours ago, tater said:

On topic, the Zubrin talk on The Space Show was pretty interesting. His meeting with Elon Musk made me realize that Musk is actually serious about this Mars stuff. I tend to forget as SpaceX "gets things done" closer to home, but Zubrin said that Boca Chica is a "shipyard" and that Musk said he wants to build 2 Starships a week.

It's good he's being serious. Even if the whole thing ends up as more of an outpost and not a colony that's a massive win for science and all of us.

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This discussion has been split off from a peripherally related thread. 

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Where will they bury the million of bodies in their time?

Cremation = recycling, due to the carbon dioxide scoops of the base.

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5 hours ago, StrandedonEarth said:

Gattaca is getting closer...

Closer with every Genome-Wide Association Study, yeah.

I'm shocked to see my one-year-old comment resurface.

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3 hours ago, kerbiloid said:

Where will they bury the million of bodies in their time?

Cremation = recycling, due to the carbon dioxide scoops of the base.

Well.... it might not be a popular idea... but I would vote for turning people’s remains into fertiliser >_<
It would only require a few very simple steps!

Edited by Dale Christopher

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11 hours ago, tater said:

Smarter people tend to have fewer kids, I was not suggesting that affluence drives IQ higher—that said, it likely maximizes available IQ (which is quite heritable, contrary to blank-slaters).

Ie: You can be genetically predisposed to be quite tall, but end up shorter because of malnutrition—if you are predisposed genetically to being shorter, while a good diet can maximize your height, it will not exceed what your genes allow. The same is true with IQ and poverty (you could have an average IQ via genetics, and be lower because of your environment). There's a guy doing machine learning on human DNA data, and you can give him your DNA, and he can tell you your height within a cm or 2. He only has educational achievement data linked to DNA, so it's much more rough on predicting that with your DNA, but if he had a large dataset with IQ and DNA for individuals, he says he could look at someone's DNA, and predict their IQ within 10 points or so.

PS—I forgot why this was in the Mars Colonization thread, lol. Because you'd have to be an idiot to want to move to Mars? ;)

 

On topic, the Zubrin talk on The Space Show was pretty interesting. His meeting with Elon Musk made me realize that Musk is actually serious about this Mars stuff. I tend to forget as SpaceX "gets things done" closer to home, but Zubrin said that Boca Chica is a "shipyard" and that Musk said he wants to build 2 Starships a week.

He said at the end that the Mars Society has a contest for designing a million person Mars colony anyone can enter.

https://www.marssociety.org/news/2020/02/11/mars-city-state-design-competition-announced/

 

Last year's winners (smaller colony of 1000 people):

https://www.marssociety.org/news/2019/10/28/mars-colony-design-contest-winners/

Wealthy people tend to have fewer kids, if you are an an poor peasant kids are cheap labor, if you are are middle class and especially live in an city kids are expensive as they have to have the lifestyle you want to display.
This is an global effect, overpopulation is dead. I say in 30-50 years an lack of workers is the main issue as the population ages. 
Yes you can use foreign labor but that just kick the bucket downward, radical life extension would solve this as in you don't get old in an long time, it has the benefit that its an product who will sell very well. 

 

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Historically, agrarian societies had more people. I do some family genealogy, and 100+ years ago, my family were farmers, and had many kids. Once they became city people... fewer kids.

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5 hours ago, magnemoe said:

Wealthy people tend to have fewer kids, if you are an an poor peasant kids are cheap labor

That is not exactly the case. There was a period when having many kids was required regardless of social stratum, and that period is over; now, children are a costly investment. So, how many children do people have? Only as many as they want, minus about half a kid.

europe-ideal-realized-fertility.png

That's because non-mechanized farming is on its way out either way.

But getting back to my original point from a year ago, there is a subpopulation that is still rather fecund - and dysfunctional, ensuring its permanent impoverishment:

gwas-fertility-personality-correlations.

16 hours ago, tater said:

The short answer is that since it's not A gene, but a complex arrangement of thousands of genes, no human could have ever figured it out. Set ML on it, and see what happens. They can tell that a fertilized egg has a constellation of genes that maps to very bad educational outcomes, and simply not select those eggs for people doing that to have kids (because the old-fashioned way isn't working for them ;) ). He said ethically, he would not select eggs for high intelligence, but it's just a matter of time before someone offers this.

Tangentially related: cognitive impairments are the most heritable of all medical conditions.

https://news.harvard.edu/gazette/story/2019/01/researchers-able-to-determine-the-effects-of-genes-and-environment-in-560-common-conditions/?fbclid=IwAR3ZFIccwj6DBoznYPz7GirtaTJv_g_e1VDNjCDd8c6y1euacJDwc0lAHfs

n=45,000,000, this is one of the largest studies ever conducted

17 hours ago, sh1pman said:

Very interesting, where can I learn more about this guy's work?

Let me throw in a few more links:

https://blog.insito.me/the-genetics-of-education-63c6f1a3f0a3

https://www.newscientist.com/article/mg24032041-900-exclusive-a-new-test-can-predict-ivf-embryos-risk-of-having-a-low-iq/

There are well over a thousand known genes associated with IQ. This is not an obstacle - Genome-Wide Association Studies allow us to very reliably tackle polygenic traits.

On 2/10/2019 at 4:54 PM, James Kerman said:

While it is true that the Flynn Effect seems to be reaching a plateau, some researchers argue that this is due to saturation of education, health, 'cultural loading', nutritional values, new technology and global connectivity in the developed world (Flynn only used data from; Australia, Austria, Belgium, Brazil, Britain, Canada, China, Denmark, East Germany, France,  Israel, Japan,  Netherlands, New Zealand, Northern Ireland, Norway, Sweden, Switzerland, United States of America, and West Germany Flynn, 1994), the actual global rate is likely continuing on an upward trajectory when these additional factors and the developing world are taken the into account.

There's also the Wilson effect to consider. Environmental factors decline with age.
EGufvMgW4AAJb83?format=jpg&name=medium

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2 hours ago, DDE said:

That is not exactly the case. There was a period when having many kids was required regardless of social stratum, and that period is over; now, children are a costly investment. So, how many children do people have? Only as many as they want, minus about half a kid.

europe-ideal-realized-fertility.png

That's because non-mechanized farming is on its way out either way.

But getting back to my original point from a year ago, there is a subpopulation that is still rather fecund - and dysfunctional, ensuring its permanent impoverishment:
 

You are correct in that all had more babies in the old days as child mortality was high, once this dropped and family planning become easier birth rates dropped. 
I did simplify a lot. 
Also birth rate in Turkey is down to 2.0, its an global downward trend. 

And yes it's subpopulations who have an higher birth rate, this is cultural. However this subculture will not keep growing because childbirths for many generations if dysfunctional.
They can grow if successful, however this growth will also be a lot because of intermarriage or up to others just joining your culture. 
If not successful most of the kids will leave and having lots of kids is expensive making it very hard to be successful in this day.

And yes down the line genetic will matter, ladies who like to have more babies will start becoming common so humans will not go extinct because of low birth rates.
However human genetic over an hundred year in the future will not be dominated by natural selection, but GM. 

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Perhaps Mars could offer some respite from any perceived genetic downtrend... even if only in an isolated pocket of humanity, since the initial population would no doubt be made up of a high proportion of highly educated, highly capable people with low genetic risk factors who probably had to make it through some highly competitive selection events in order to get there. It would seem to be a nice gene pool in which to breed if you valued how much brain matter someone could bring to bear over how much baby batter.

Edited by Dale Christopher

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