How about a counter effect? Many couples today reproduce with the assistance of reproductive technology. This releases selection pressure, so low-fertility genes proliferate.
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The heritability of fertility makes world population stabilization unlikely
91–100 of 154 posts
Re: The heritability of fertility makes world population stabilization unlikely
#92Earlier quoted context omitted.
> The premise of heritable fertility driving population and reproduction rates in humans is really far off. Yes, until reliably accessible contraception fertility was driven by the desire to have sex. > If it were true fertility rates could not possibly have dropped so far in so few generations after modern medicine and the insane reduction in violent death rates seen in the last thousand years. This assumes no chang…
I agree, however this doesn't necessarily mean that average fertility will rise again. The environment could keep changing faster than the genes can adapt. Also "desire to have children" might be difficult to encode in DNA so genetic adaptation to the availability of contraceptives might be really slow.
This is the strongest (only?) counterargument I've seen. I don't believe it will happen soon though. Politicians only do something when doing something is less controversial than doing nothing and that's pretty far off.
Re: The heritability of fertility makes world population stabilization unlikely
#93This is the opposite of what Hans Rosling says in his book Factfulness.
According to Hans Rosling's findings family size is linked to child mortality which is linked to poverty. When mothers see their children die then they want to have more children. When they see their children grow to adulthood then they have fewer children. You can also play with the data yourself on his site https://www.gapminder.org/.
He also looked at family size relation to culture and religion and found even in religions that promote large families, family size is still declining.
Family size has dropped world wide everywhere except for Africa. There is an unfortunate link between poverty and family size in Africa. The Bill and Melinda Gates foundation is tracking this exact issue.
I am not a data scientist, but the heritability of large families seems a difficult thing to pull out of the data when environment plays such a large role. In my personal family history child mortality and religion did play a large role in family size. We all now have small families.
Re: The heritability of fertility makes world population stabilization unlikely
#94Earlier quoted context omitted.
I'd dispute a lot of what is in that source. Their heat-maps of various characteristics are a correlation only, and a correlation among things which tend to go together (fertility rate, tv ownership (wealth), gdp per capita, and female literacy usually increase in tandem as part of a cultural shift). This does not necessarily mean they cause each other. Also, ought we really to be brainwashing people to live how we w…
All good points. While I think TV is perhaps too specific an example, my personal hypothesis is that availability of other forms of entertainment is a cause of declining birth rate. I’d say close to half of my married friend couples do not plan on having kids, and their main reasoning is usually that they like their social life, freedom to travel, ability get out in the weekends and generally do what they want. Also…
Imo, it is more that having children has often effect of isolating you quite a lot. It can get very lonely as a result as you miss adults around. You miss friends with common interests as your social group become exclusively those with same age children but not much in common otherwise.
It is not necessary that entertainment is so great.it is more that routine and isolation can be quite big.
TV is compatible with kids. But most social activities are nowdays are not.
Re: The heritability of fertility makes world population stabilization unlikely
#95This is the opposite of what Hans Rosling says in his book Factfulness. According to Hans Rosling's findings family size is linked to child mortality which is linked to poverty. When mothers see their children die then they want to have more children. When they see their children grow to adulthood then they have fewer children. You can also play with the data yourself on his site https://www.gapminder.org/ . He also…
This is a 20+ year recollection...but while working on a Masters in Public Health, we learned that the only causal factor that could be linked to both number of children birthed and age at which a woman gives birth to her first child is the education level of the mother. That is, as women in a society have greater access to education, they postpones when they have their first child and in the end have fewer children in their lifetime.
Re: The heritability of fertility makes world population stabilization unlikely
#96This is the opposite of what Hans Rosling says in his book Factfulness. According to Hans Rosling's findings family size is linked to child mortality which is linked to poverty. When mothers see their children die then they want to have more children. When they see their children grow to adulthood then they have fewer children. You can also play with the data yourself on his site https://www.gapminder.org/ . He also…
When evolution looks at reason, it is invisible.
All the process sees are numbers, and the numbers pointing to reason beeing a procreation inhibiting disease.
So reason is circumvented.
Drug addicted?
Mental illness?
Traumatized by war?
Escapezombie?
Just plain reckless?
You are imune to the disease. You are the future.
Re: The heritability of fertility makes world population stabilization unlikely
#97Earlier quoted context omitted.
One of the sources: https://journals.plos.org/plosone/article?id=10.1371/journal... >> This finding implies that individuals with genetic predispositions for an earlier AFB had a reproductive advantage and that natural selection operated not only in historical, but also in contemporary populations. The observed postponement in the AFB across the past century in Europe contrasts with these findings, suggesting an evol…
Because that never happened before in human history: https://www.amazon.com/s?k=Who+We+Are+and+How+We+Got+Here&re...
What exactly is your point?
Re: The heritability of fertility makes world population stabilization unlikely
#98Earlier quoted context omitted.
It's not "obvious" at all and I've never heard anyone in the community express such sentiments, even in more informal settings. I don't even know what "courage" you're referring to. The courage to be associated to a journal with an IF < 4, maybe?
This obsession with journal impact factor is toxic in academia. It's what allows parasitic publishing companies to continue to extract rents despite contributing nothing to science for decades. The majority of papers are envelope-pushers, churned out in enormous numbers because of "publish or perish". Academics who need CV bullet-points are going to churn out quick papers that go with the status-quo, with bibliograph…
I don't get the point.
If science does care about the JOURNAL impact factors too much, why then, as a consequence, would everyone publish in low impact factor journals?
Re: The heritability of fertility makes world population stabilization unlikely
#99Earlier quoted context omitted.
It's not "obvious" at all and I've never heard anyone in the community express such sentiments, even in more informal settings. I don't even know what "courage" you're referring to. The courage to be associated to a journal with an IF < 4, maybe?
This obsession with journal impact factor is toxic in academia. It's what allows parasitic publishing companies to continue to extract rents despite contributing nothing to science for decades. The majority of papers are envelope-pushers, churned out in enormous numbers because of "publish or perish". Academics who need CV bullet-points are going to churn out quick papers that go with the status-quo, with bibliograph…
While I agree there are plenty of issues in academia among which too much emphasis on IF is certainly a thing, it does provide a helpful filter (or prior, if you will) to quickly assess whether some material is worth your time. In this case, stuff in low-IF journals that are virtually unknown in the community (e.g. there are a few journals like Bioinformatics that are also fairly low-IF but very well respected), whose conclusions can't help but provide ammunition for a political point, all accompanied with commenters hinting that there's some grand omerta in the community (lol, as if we didn't already have problems pushing the obvious stuff like climate change first), all of that adds up to something rather suspicious.
Please don't regurgitate common talking points about academia issues if you're just trying to score points in support of a fringe political position, that's not at all the direction we (as scientists that are critical of academia) want to go.
Re: The heritability of fertility makes world population stabilization unlikely
#100Some anecdotal data. My father's parents had 8 surviving children. My mother's parents had 8 surviving children. My parents had 4 surviving children. I have 4 children. My siblings have, on average, 3 children, and will probably have 3.5 over time. My cousin's have on average 3.5 children. Grandparents: Asian. Parents: Asian and lived in Middle East half their life. Me and siblings: Living primarily in Middle East.
"Asian" is too broad to be a useful descriptor of ethnicity or culture.