Children of older fathers have less evolutionary fitness

Angela

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The results seem to hold over four generations and four geographic areas.

See:
http://biorxiv.org/content/biorxiv/early/2016/03/08/042788.full.pdf

"Higher paternal age at offspring conception increases de novo genetic mutations (Kong et al., 2012). Based on evolutionary genetic theory we predicted that the offspring of older fathers would be less likely to survive and reproduce, i.e. have lower fitness. In a sibling control study, we find clear support for negative paternal age effects on offspring survival, mating and reproductive success across four large populations with an aggregate N > 1.3 million in main analyses. Compared to a sibling born when the father was 10 years younger, individuals had 4-13% fewer surviving children in the four populations. Three populations were pre-industrial (1670-1850) Western populations and showed a pattern of paternal age effects across the offspring's lifespan. In 20th-century Sweden, we found no negative paternal age effects on child survival or marriage odds. Effects survived tests for competing explanations, including maternal age and parental loss. To the extent that we succeeded in isolating a mutation-driven effect of paternal age, our results can be understood to show that de novo mutations reduce offspring fitness across populations and time. We can use this understanding to predict the effect of increasingly delayed reproduction on offspring genetic load, mortality and fertility."

It seems that with all the advantages of modern medicine, the disadvantages can be ameliorated.

That wasn't the case in prior eras. That means that this social construct, where older men who have acquired more wealth and power have more access to women, was actually not very beneficial in terms of the overall health of the population, yes? Their genes would not, in those cases, be disproportionately being passed down, so how does impact our understanding of the processes of the past?
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My father was born when his father was 50, he has 5 children more than any of his siblings( he's the youngest) and is 65 years old now and is healthy thank God.
 
This claim about "less evolutionary fitness" of children of older fathers is utter nonsense, because prior studies have shown a long-term trend of correlation between higher paternal age at offspring and increasing average IQ of the population.

Maybe precisely these de novo genetic mutations are influencing brain function and contributing to higher average IQ.

If by "evolutionary fitness" they mean being well-adapted to R-selected simple jungle lifestyle, then maybe they are right.

But such model of early reproduction did not lead to adaptation to modern civilization and to high IQ societies.

People evolved higher IQ in areas where couples tended to marry and to have children long after 20. North-Western Europe is where parents tended to be older than anywhere else in the world during the last several centuries. Is North-Western Europe "genetically messed up" because of that, compared to areas where people reproduce as teenagers (for example Africa)?

What actually is this "fitness" anyway ???

I have read somewhere that all Eurasians have much lower fitness than Sub-Saharans because they are less genetically diverse, descended from a bottlenecked population (the Out-of-Africa Tribe), and because they mixed with Neanderthals (mixing with Neanderthals supposedly - quote - "lowered fitness of Non-Africans by 0.5% comapared to Africans").
 
That means that this social construct, where older men who have acquired more wealth and power have more access to women, was actually not very beneficial in terms of the overall health of the population, yes?
No. As I wrote, it is utter nonesense. And it is not a "social construct" but an evolutionary trend.

Older men who acquired wealth and power were boosting the average IQ of the population by passing their genes.

That is how we got from ~70 points to ~100 points between the Paleolithic and the 21st century.

"De novo genetic mutations" is what drives the evolution forward, by the way...

In other words: populations where people reproduce as teenagers are not evolving.
 
This claim about "less evolutionary fitness" of children of older fathers is utter nonsense, because prior studies have shown a long-term trend of correlation between higher paternal age at offspring and increasing average IQ of the population.
It is only correlation. The cause of rising IQ and age of parents, is related to rising technological advancement and wealth of societies. Kids get extensive education couple of decades long, learn many games and are bombarded by non stop information. This trains brains increasing IQ. The same well off societies tend to have kids later in life, unlike HGs who start at age of 12-14, and not much later for simple farmers at 15.

Maybe precisely these de novo genetic mutations are influencing brain function and contributing to higher average IQ.

If by "evolutionary fitness" they mean being well-adapted to R-selected simple jungle lifestyle, then maybe they are right. But Sub-Saharan model of early reproduction did not lead to adaptation to modern civilization and to high IQ societies.

People evolved higher IQ in areas where couples tended to marry and to have children long after 20. North-Western Europe is where parents tended to be older than anywhere else in the world during the last several centuries. Is North-Western Europe "genetically messed up" because of that, compared to areas where people reproduce as teenagers (for example Africa)?

What actually is this "fitness" anyway ???
We know that late age of fathers causes more mutation in sperm and increases frequency of down syndrome in kids for example. Generally speaking, by nature of things, most mutations are negative than positive therefore will affect offspring survival negatively.
 
Higher IQ amongst children of older fathers can easily come from the fact that rather than spending time teaching sons sports, older men prefer to sit down with the children and share knowledge if not "wisdom".
 
No. As I wrote, it is utter nonesense. And it is not a "social construct" but an evolutionary trend.

Older men who acquired wealth and power were boosting the average IQ of the population by passing their genes.

That is how we got from ~70 points to ~100 points between the Paleolithic and the 21st century.

"De novo genetic mutations" is what drives the evolution forward, by the way...

In other words: populations where people reproduce as teenagers are not evolving.
And how do you explain the progress we did since swinging on trees and barely walking Lucy 3 million years ago to Neolithic? We were all hunter gatherers having first kids at 12, and not living longer than 35 years. For most of farming existence not much better, kids at 15 and lifespan of 40 years.
 
Higher IQ in children of older fathers can easily come from the fact that rather than teaching their sons sports, older men may prefer sitting down with their kids sharing knowledge if not "wisdom".
 
by nature of things, more mutations are negative than positive

Not true.

Mutations are random which means that the chance of positive to negative will be 50 to 50.

Most of mutations are in fact neutral and have no effect on anything.

Real proportions are most likely something like 90% neutral, 5% positive and 5% negative.

=======================

The paper did not mention positive mutations because it is now "politically incorrect" to admit that humans are still evolving (Henry Harpending and Gregory Cochran wrote that "people in different parts of the world are still evolving, and evolving differently" - they were labeled as "racists"). This paper is another attempt to disparage "Cis White Male R1b Patriarchs".

"Cis White Male R1b Patriarchs" are not my words. One of moderators coined this term some time ago.
 
IQ doesn't get higher from teaching. It's innate. Also, even if that could happen, i.e. IQ getting higher because of better teaching from older fathers, any speculative higher IQ in the children of older fathers is irrelevant if more of them are unfit in evolutionary terms and so a higher percentage of them die before being able to reproduce, a problem that persists into subsequent generations. (It's true an older, presumably older father would have more resources to lavish on offspring, which tells you how real the phenomenon must be, if even with those advantages there are these kinds of outcomes.)

Note that we're talking here about percentages. This isn't going to impact all the children. They're talking about an increase in the percentage of children who are not fit in evolutionary terms, not that all of them are so affected. Still, of course, an increase of a certain percentage in each generation is going to have wider societal implications. Nowadays, of course, we can keep children alive and able ultimately to reproduce even if they are not optimally fit. What the consequences will be for the human race is another question altogether.

I have to say I'm surprised about the lack of knowledge concerning this phenomenon as well as the lack of knowledge of IQ and genetics as a whole.

Most de nova mutations are harmful. Doesn't everyone know that?
http://massgenomics.org/2012/08/de-novo-mutations-and-human-disease.html

We've also known for years that parental age at conception is a problem for fitness. There's a big correlation between paternal (and maternal) age at conception and the incidence of Down's Syndrome too, and autism, and a number of other disorders. This is just elementary genetics, people: with age, the cells break down more, which is why cancer is usually a disease of the elderly too.
https://www.ncbi.nlm.nih.gov/pubmed/12771769

There's a reason most sperm banks don't want any sperm from men over 35, people.

European societies didn't need geneticists to tell them this either, just like they didn't need geneticists to tell them too much inbreeding wasn't a good idea. We have lots of Italian old wives' sayings about the perils of very old men fathering children. Not in every instance, of course.
 
I would advise certain posters to cease posting incorrect, unsourced opinions. Anyone can make a mistake or be un-informed, of course, although this is pretty basic genetics, but when it has been pointed out that the opinion is scientifically unsound, to insist on it comes perilously close to trying to deliberately distort the record.
 
IQ doesn't get higher from teaching. It's innate.

It does from de novo genetic mutations, not from teaching.

What the consequences will be for the human race is another question altogether.
There will be no any consequences for the human race, because there is no such thing.

There are several human races (or rather taxa, if someone doesn't like the term "race").

There's a reason most sperm banks don't want any sperm from men over 35

Yes, and this reason is saving money.

They could just screen them for potential harmful mutations instead. But this is extra cost.

It does not mean that the probability that they developed some bad mutation is high.

And as I wrote, the probability of a beneficial mutation is the same as that of a bad one.
 
Opinions un-supported by scientific data, or, indeed, refuted by scientific data are irrelevant, and no one takes them seriously, nor should they.

I would suggest some basic reading in the intelligence quotient and its heritability, and the number and nature of de novo mutations. DE NOVO MUTATIONS ARE USUALLY HARMFUL, AND THE INCIDENCE INCREASES WITH AGE, deny it as some people would like to do for some unknown, strange reason.
 
Mutations are random and have random effects, so why would they be more often harmful than beneficial.

It is like saying that you will usually get the number "one" if dice is rolled 1000 times. It makes no sense.
 
Is there a problem with reading the links to scientific studies?

http://massgenomics.org/2012/08/de-novo-mutations-and-human-disease.html

"[FONT=&quot]Many, if not most human diseases have a genetic component. Thanks to advances in next-gen sequencing, a plethora of studies in recent years have shed light on the role of germline variants in heritable diseases, and of somatic mutations in cancer. They are also beginning to unravel the role of true [/FONT]de novo[FONT=&quot] mutations — genetic variants that arise in a child but are not present in either parent — in human disease. This was the subject of an excellent article just out in [/FONT]Nature Reviews Genetics[FONT=&quot]. Let me give you the highlights.[/FONT][FONT=&quot]Most of what we know about de novo mutations in humans comes from recent whole-genome and exome sequencing studies in families:[/FONT]

  1. On average, humans acquire ~74 de novo single nucleotide variants (SNVs) per genome per generation.
  2. The rate of de novo mutations seems higher in individuals with genetic diseases, particularly sporadic disorders such as intellectual disability and autism.
  3. Perhaps surprisingly, the de novo mutational load seems correlated with paternal (as opposed to maternal) age.
  4. Mutations linked to sporadic disease are usually highly disruptive to gene function, often affecting important domains of developmental genes.
[h=2]Diseases Linked to de novo Mutations[/h][FONT=&quot]De novo mutations tend to be more deleterious than inherited variation because they haven’t undergone the same level of evolutionary selection. This fact, combined with the observation that they occur with some appreciable frequency, makes de novo mutation an an intriguing explanation for sporadic diseases. In support of this notion, recent family-based exome sequencing studies have implicated de novo mutations in a number of rare syndromes."

Please use google search to find the many articles on this subject if interested in the topic.[/FONT]
 
Nothing in what you quoted implies that de novo mutations are more often deleterious than beneficial. Saying that they are "more often deleterious than inherited variation" =/= saying that more of them are deleterious than beneficial.

Nothing in what you posted proves my claim (that probability of them being harmful is the same as probability of them being beneficial) wrong. Inherited mutations are - of course - much more often beneficial than they are harmful.

But de novo mutations are not more often harmful than they are beneficial. Proportion is exactly 50:50. I mean, proportion of beneficial to harmful ones is 50:50. If we add neutral ones, then it is 90:5:5 (with 90% being neutral).

deny it as some people would like to do for some unknown, strange reason.

I plan to have a child or a few before 35 years of age, but I plan to have one or a few also after 35 years of age.

But this is not the reason why I deny it. The reason why I deny it is because it is wrong, and I am right.
 
Not true.

Mutations are random which means that the chance of positive to negative will be 50 to 50.
Nope, it is not an issue of something being good or bad by some universal forces. You see our DNA is very finely tuned "machine" where genes cooperate with each other. In this case any changes in this machine will be mostly negative. Imagine an old fashion watch. Open it and look at all the gears nicely working inside. Now try to do a random modification to any of these gears. Add more teeth to some gears, make square gears, o much bigger, and I assure you that the watch will stop working. Only in rare situation little modification of fine tuned watch will be positive. Like a modification making all gears physically stronger, or all proportionally bigger. Of course, if environment rewards such change.
It is a similar situation with our DNA. Most changes are distractive, varying from very destructive to mildly negative to neutral, and only microscopic amount of changes are truly positive.
 
In this case any changes in this machine will be mostly negative.

This claim is unsupported by evidence. I did not find this statement in what Angela posted.

All what that paper says is that inherited mutations are less often harmful than de novo ones.

But inherited mutations are not harmful in the vast majority of all cases.

De novo mutations are still at least as often beneficial as they are harmful.

Angela quoted this fragment:

Perhaps surprisingly, the de novo mutational load seems correlated with paternal (as opposed to maternal) age.

Evolution made women fertile only until middle age, while men are fertile much longer. If de novo mutations associated with paternal age (but not maternal age) were really harmful, then it should be the other way around - men should be fertile only until middle age. For some reason evolution did not "want" older women to reproduce, but it did "want" older men to do it.

Why should I trust this paper more than I trust evolutionary evidence? Evolutionary evidence shows that women after menopause cannot naturally reproduce (so probably should not try artificial methods either), but older men still can.
 
Nothing in what you quoted implies that de novo mutations are more often deleterious than beneficial. Saying that they are "more often deleterious than inherited variation" =/= saying that more of them are deleterious than beneficial.

Nothing in what you posted proves my claim (that probability of them being harmful is the same as probability of them being beneficial) wrong. Inherited mutations are - of course - much more often beneficial than they are harmful.

But de novo mutations are not more often harmful than they are beneficial. Proportion is exactly 50:50. I mean, proportion of beneficial to harmful ones is 50:50. If we add neutral ones, then it is 90:5:5 (with 90% being neutral).



I plan to have a child or a few before 35 years of age, but I plan to have one or a few also after 35 years of age.

But this is not the reason why I deny it. The reason why I deny it is because it is wrong, and I am right.
Same as you were right with "population of young fathers not evolving." ;) Any explanation what happened from Lucy to Neolithic?
 
Same as you were right with "population of young fathers not evolving." ;) Any explanation what happened from Lucy to Neolithic?
Nope, your "guesstimates" that people in prehistory reproduced at 15 and lived 35 were wrong.

The truth is that in prehistory 50% of people died before the age of 15 (with 30% dying before the age of 5), and thus did not reproduce at all. The remaining 50% lived on average 55-60 years, and reproduced after 20-30 just like we today.

Read about age distribution of mortality rates. In the past, death was a thing that affected mostly children.

At least 1/2 of all people were never becoming adults because they were dying before turning 18.
 

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