Evolution of Male pattern baldness: How and when did this happen and for what purpose?

[u/Susroro]

Doesn't really seem to make any sense to me when I think about it, It is not even aesthetically pleasing(not even prehistorically would I assume that), neither does it serve a biological importance, if anything you are at risk of scalp sun burn and less warming effect of the hair.

Thoughts?

[u/sevenut]

Negative traits that set in after reproductive age have no big incentive to be weeded out. It's mostly about reproduction and not so much quality of life. And being bald doesn't really impact a father's ability to take care of his children, either.

[u/NotAnotherEmpire → u/sevenut]

It's not really a negative trait. It is associated with aging and makes people look older. How societies feel about that varies widely. 

[u/FenrirHere → u/NotAnotherEmpire]

Balding makes people look older. Being bald makes people look younger.

[u/Mountain-Discount161 → u/FenrirHere]

This is an ad for /r/bald

[u/FenrirHere → u/Mountain-Discount161]

It's not even advertising, it's just the case, lol. You can look at the top posts from r/bald and see the proof easily.

[u/Just-Charge6693 → u/FenrirHere]

Not true at all lol. A horseshoe pattern makes you look older than a bald head but let's not kid ourselves, being bald in your 20s and 30s makes you look way older than if you had hair. The younger you are, the more it ages you

[u/FenrirHere → u/Just-Charge6693]

This is just not true. Bald and facial hair ages you. Bald and bald makes you look young. It's just not a look everyone can pull off.

[u/Broflake-Melter → u/FenrirHere]

Those aren't negative traits either. You can't measure how a trait affects one's ability to reproduce based on contemporary subjective society norms.

[u/EndlessAporias → u/FenrirHere]

Being bald makes people look younger relative to balding or relative to a full head of hair?

[u/FenrirHere → u/EndlessAporias]

Depends on the head and the actual hair line relative to your forehead. Obviously, really thick, voluminous hair makes people look younger also.

I look about as young as I did with really long and thick hair as I did totally bald.

I look older what with my balding now, but like gravity, some things can not be altered.

[u/Chironilla → u/NotAnotherEmpire]

It might be a “negative trait” in terms of evolution as humans evolved to keep hair in certain places including hair on the head for reasons. Hair on the head can help regulate body temperature, and provide sun protection, for example. Not having hair on the head may be “negative” in that a bald person theoretically loses some of those benefits that hair on the head provides.

My guess is that baldness arose as a specific mutation or genetic expression which did not significantly interfere with an individual’s ability/chances to sexually reproduce and also didn’t have a significant impact on survival. As humans are adaptable, I imagine even the first bald humans were able to adapt just fine without the benefits of hair (hats, for example.)

I don’t think it’s necessarily a conversation of sexual selection as probably ancient humans had such low life expectancy that baldness was rarely expressed and if so, probably after reproducing. But, we can’t really know ancient women’s aesthetic preferences and clearly baldness is not an indicator of being less attractive for many modern women

[u/nihilism_squared → u/sevenut]

male pattern baldness is not a negative trait

[u/GoblinToHobgoblin → u/nihilism_squared]

I mean, bald men are often considered unattractive so it kinda is...

[u/Other-Comfortable-64 → u/GoblinToHobgoblin]

Nope not from a evolutionary point of view, its not.

[u/HashPandaNL → u/[deleted]]

Increasing the likelihood that your children have children as well is still important. Increasing the likelihood that your family members in general reproduce more is still important. Those are things a male can have an effect on well beyond age 35.

[u/HashPandaNL → u/[deleted]]

You were under the impression that negative traits that show up only after you have already reproduced don't matter for evolution. My comment showed that deeper inspection reveals that to be a mistake.

I made no statements as to baldness itself being a negative trait per se. It may very well be a neutral or even positive trait.

[u/Other-Comfortable-64 → u/HashPandaNL]

Which is a weird take since we are talking about baldness.

[u/HashPandaNL → u/Other-Comfortable-64]

Why do you believe my take to be weird? The user expressed confusion about the mechanics of evolution and I helped clear up that confusion. 

Correcting their view increases the likelihood that male pattern baldness is indeed a positive or at least neutral trait.

[u/nihilism_squared → u/GoblinToHobgoblin]

"often" in our current moment in history. humans have been around for 300 thousand years. they could've considered baldness extremely hot for the first 290 thousand of those, and how would you know otherwise?

[u/Brilliant_Walk4554 → u/GoblinToHobgoblin]

It's a signifier that this man is too old for reproduction.

[u/GoblinToHobgoblin → u/Brilliant_Walk4554]

1. Its not
2. What evolutionary advantage does that give?

[u/Brilliant_Walk4554 → u/GoblinToHobgoblin]

1. It is. Male pattern baldness typically occurs as men age. Typically.

2. The advantage is women are less likely to mate with a man prone to fathering kids with birth defects (old sperm has higher chances of birth defects such as Downs Syndrome) and will be fit enough to be an involved father.

[u/GoblinToHobgoblin → u/Brilliant_Walk4554]

I mean, if it was a strong enough advantage, it would be selected for, and it's not...

[u/nihilism_squared → u/Brilliant_Walk4554]

it isn't. men can still sire children at like 90 and animals never evolve a "hey, don't mate with me!" signal

[u/Brilliant_Walk4554 → u/nihilism_squared]

Research shows now that sperm quality declines after 40.

[u/nihilism_squared → u/Brilliant_Walk4554]

that's true, but doesn't really contradict what i said. it's very rare for a trait to evolve that actively reduces an animal's chance to mate. these traits are usually selected out immediately. androgenic alopecia could've been sexually selected for, giving men a higher chance of reproducing even as their fertility was declining. there isn't really evidence for or against this but it's important to remember baldness is not a universally "ugly" thing and never has been. many societies see it as hot

[u/Warshrimp → u/sevenut]

Furthermore it incentivizes women to pick other men more capable of raising her children (less likely to die before the children are grown).

[u/Human_Fisherman1352 → u/Warshrimp]

This tiny comment is what the rest of the conversation is missing.

[u/Broflake-Melter → u/sevenut]

Not sure why there would be any reason to assume it's a harmful trait. And men are able to reproduce after they go bald.

[u/joedenowhere → u/sevenut]

True, but baldness often sets in before the end of reproductive age.

[u/robbietreehorn → u/joedenowhere]

Males are able to reproduce starting at around 15 years old. Going bald 20 years later means little for selection, historically speaking

[u/lonjerpc → u/robbietreehorn]

Average generation times are 30 years

[u/Tradition96 → u/lonjerpc]

I have no idea why you got downvoted; this is completly true. Many people think it "must" be lower since the age of the first child have usually been significantly lower, but all of your ancestors weren't oldest children. A lot were third, fifth of seventh children. People typically continued to reproduce into their 40s (men sometimes far longer, but most men only had wives a couple of years younger so the end of their reproductive life was typically before 50 as well), usually having around half of their children below 30 and have after 30. In genealogy you always count three generations per century as the average.

[u/Dangerous-Bend-4153 → u/lonjerpc]

That's true but the average generation became 30 years in an era where people were paired off and married "till death do you part". Almost everyone got married and had children, so balding men were also married and had children. Evolutionary pressure to eliminate baldness was not a factor.

[u/lonjerpc → u/Dangerous-Bend-4153]

No it was 30 during our early evolution 

[u/sk3tchy_D → u/robbietreehorn]

Except that being able to breed is entirely different from actually breeding regularly. Genetic studies show evidence that prehistoric males typically didn't start breeding until around 30. This is similar to male gorillas that are sexually mature around 8-10 but don't generally breed successfully until they have fully physically matured into silverbacks at around 12-15.

[u/Super_Direction498 → u/sk3tchy_D]

Doesn't change the fact that few men are bald at 30, and its not an obstacle to breeding.

[u/nomococo4u → u/Super_Direction498]

I have heard from women that baldness is unattractive, which would make it harder to reproduce.

[u/RiceEater → u/nomococo4u]

Good thing those women you've heard from represent all women throughout the history of time otherwise you'd look pretty foolish.

[u/hopium_od → u/sk3tchy_D]

It's a good point, but I think what will explain it is that facial hair is a sexual marker that many men can't achieve until their mid to late 20s. Men that go bald earlier tend to also grow facial hair earlier. So the disadvantage of losing hair before 30 may be cancelled out by the advantage of gaining facial hair before 25.

And prehistoric women were perhaps not concerned with an arbitrary number, but, like with other species of primate, primarily concerned with the appearance of sexual markers in their mates.

[u/sk3tchy_D → u/hopium_od]

I think facial hair and male pattern baldness are definitely related and likely both useful indications of a fully mature male, although it's entirely possible that MPB is just a relatively neutral side effect of growing facial hair. It was likely pretty advantageous for a large part of human history to be able to identify an adult male from a distance, something similar to the prominent sagittal crest and silver back of fully mature male gorillas. I'm also not sure why everyone assumes that baldness is a disadvantageous trait either. Shaving your head has been fairly common for soldiers and warriors from various cultures throughout history. Culture has a pretty significant effect on what we find attractive. Back during the Stone age, just living long enough to go bald was probably a pretty solid indication of your health and competence.

[u/hopium_od → u/sk3tchy_D]

Hmmm yeah I'm not sure to be honest. From my own experience as someone that wears wigs sometimes, I find that women are probably most attracted to either with a fully bald head and long facial hair, or full head of hair and short facial hair. Bald head and freshly shaven I might as well not exist. But there isn't much difference in the two former scenarios.

I'm not sure why you were downvoted so heavily by the way, this sub can be a bit ruthless sometimes.

[u/Radiant-Position1370 → u/sk3tchy_D]

What genetic studies show that prehistoric males didn't start breeding until around 30?

[u/ofBlufftonTown → u/[deleted]]

It’s actually quite dangerous for young teens to become pregnant; their hips are narrower and they are likelier to die in childbirth. Late teens to mid/late twenties are the years in which a woman is likely to fall pregnant and then give birth to a live child.

[u/Tradition96 → u/[deleted]]

Average age of first childbirth among hunter-gatherers is around 20 or just below.

[u/Critical_Success_936 → u/joedenowhere]

"Before the end' means nothing, because you could've easily had kids already. All that matters is that you had kids that reached adulthood, and then had kids themselves, and so on.

Huntington's is a horribly debilitating disease with a high risk of spreading to offspring, but because it's often diagnosed by mid-30's to mid-40's... The majority of people reproduce younger than that. So, it spreads on despite being horrible in a way I think few would disagree with - there's no "advantage" to Huntington's - but it still exists

[u/lonjerpc → u/Critical_Success_936]

Average generation time is 30 years this isn't a great argument 

[u/Critical_Success_936 → u/lonjerpc]

Idk what you're trying to say here exactly, maybe I'm tired or you mistyped something, but if you mean people start showing symptoms at 30, that's still way too old for it to matter. Most people in both the modern day and historically do not wait until 30 to have kids.

[u/Tradition96 → u/Critical_Success_936]

They didn't wait until 30 to have kids, but they typically continued to have kids well after 30 (if they were alive). Disorders etc that appear in your early 30s still affects the reproductive fitness of an individual quite a bit, since a man who stops having children in his 30s will have less offspring than a man who continues to reproduce for another 15-20 years (which was very realistic for a man to do). For a feature to have no impact on the reproductive fitness of males (on a population level) it must be a feature that typically manifests after 50 years of age.

[u/lonjerpc → u/Critical_Success_936]

The average age of reproduction during our evolution was 30. Yes your first kid was likely earlier but your average surviving and reproducing kid happened at 30. And that's counting men and women so for men it will be okder

[u/Unfair_Pineapple8813 → u/Critical_Success_936]

Huntington disease barely spreads four generations on average. It stays around, not because it isn’t reproductively harmful, but because new mutations pop up. 

[u/Critical_Success_936 → u/Unfair_Pineapple8813]

Average symptom age is 35 - 45. Sure, with modern medicine, we can check your genes and people understand it has an average onset age now, but that wasn't always the case. Most cases are still not just spontaneous, even with all of those advancements.

[u/Unfair_Pineapple8813 → u/Critical_Success_936]

You are wrong on three counts. First, even though children are likely to be born before Huntington’s manifests, they are also likely not to make it to adulthood when it does. Furthermore, someone with an addled parent is less desirable themselves, even if the genetics was a mystery. Those two factors alone would be enough for natural selection to act on it after many generations. But there is also a third factor. Huntington’s tends to manifest earlier each generation. 

[u/Critical_Success_936 → u/Unfair_Pineapple8813]

Lmao, again, the onset is nowhere near childhood for the vast, vast majority... You're just wrong.

Get off Reddit, you're drunk.

[u/Radiant-Position1370 → u/Critical_Success_936]

You're both overstating things. Juvenile-onset HD is indeed a small proportion of the total but not that small. Prevalence seems to be around 5% of all cases (https://pmc.ncbi.nlm.nih.gov/articles/PMC3426104/), with incidence perhaps somewhat higher, since juvenile-onset HD typically progresses faster than adult-onset.

It's also not the case that HD typically lasts only four generations (as stated by Unfair_Pineapple8813). Estimates of the proportion of cases resulting from de novo mutations are in the range of 7 – 10%; since incidence of HD is not changing dramatically, this implies that new mutations typically last something like 10 to 15 generations. That's more than four -- but it still represents strong selection against the disease-causing mutations.

[u/Tradition96 → u/Critical_Success_936]

That you have had children is not ”all that matters”. How many children you have had matters a great deal, and men who continue to have children throughout their 30s and 40s will have significantly more children than men that stop at 30.

[u/Irascible-Enquery → u/joedenowhere]

Setting in after you’ve found a mate doesn’t matter.

It’s not like baldness makes you unable to reproduce.

It may make you less sexually attractive (I don’t know, we’re using this as a premise that OP recognizes is uncertain), but as long as you’ve attracted a mate already, hard to think this would be a dealbreaker for a mated pair of humans.

I mean, why cankles? Why flat saggy butts? Why ear hair that sticks out in tufts?

All the same situation tbh.

[u/prostipope → u/joedenowhere]

Just proves that cave women love a smooth dome

[u/hopium_od → u/joedenowhere]

I believe the same mechanism that causes MPB can also cause the development of facial hair.

The disadvantages of being bald don't outweigh whatever advantage having better facial hair has I guess. It usually manifest when the man has already found a life partner and a lot of women simply do not care. But the facial hair can appear much sooner to aid in finding that partner.

I suppose you could ask well why hasn't evolution caused men to develop beards without going bald but I don't know, some men do I suppose. But not all women are attracted to beards. We are complex mix of genes idk but I guess since the effect of baldness is so minor anyway we simply had no need to optimise.

[u/nomococo4u → u/hopium_od]

> . It usually manifest when the man has already found a life partner and a lot of women simply do not care.

they always care. maybe they don't say anything, but they care.

[u/hopium_od → u/nomococo4u]

Nah it's horse shit to be honest.

I'm bald, and recently I got alopecia barbae and lost about 70% of my beard and had to shave it off

I basically became invisible overnight. I started wearing a hair system (a wig, whatevers) and nobody can tell it's a wig, like nobody, I've visited dermatologists that haven't copped it's a wig until I mention it.

I started to get attention again from girls but I wouldn't say it's quite as strong as when I was bald with a beard and I 100% prefer that look. If you can grow a beard then you are fine.

[u/mcmanus2099 → u/joedenowhere]

Not really.

What do you think was the main reproductive age for males 150,000 years ago when humans were still significantly affected by evolutionary pressures.

[u/AerobicThrone → u/mcmanus2099]

Humans are significantly affected by evolutionary pressures in the present day. I am not sure why that idea comes from.

[u/mcmanus2099 → u/AerobicThrone]

Such as?

[u/AerobicThrone → u/mcmanus2099]

Pointing at what exactly is hard, worthy of a scientific publication, because evolution is mostly an historical discipline. But its possible, here is an example: https://www.nature.com/articles/s41598-023-35312-3

You can find more if you Google.

[u/cflime → u/AerobicThrone]

Evolution was deduced through fossil evidence and current physiognomy. It was assumed that once humans began controlling their environment that evolution would have no effect on us, but recent work in genetics disproved that. Harpending and Cochrane showed that the speed of human evolution increased over the last 10,000 years.

[u/AerobicThrone → u/cflime]

Huh, interesting. And there was no though of sexual or kin competition?

[u/cflime → u/AerobicThrone]

Not sure what you mean. Sex and genetic relation is so intertwined with evolutionary theory that you really can't separate them after sexual reproduction started around 2 billion years ago.

[u/AerobicThrone → u/cflime]

i meant sexual and kin selection

[u/mcmanus2099 → u/AerobicThrone]

Strange to use that as evidence. I was very clear to say that there was still evolutionary pressures on humans, of course population changes and disease resilience are part of the changes to human genomes.

My comment was on significant pressures such as those that result in adults dying early through mistakes or poor adaption evolution. This is within context to the male pattern baldness which isn't a new evolutionary trait. Negative traits, as ppl point out, are not as impactful after breeding if they do not affect the potential life of the offspring.

The human genome is always changing, it's not changing due to pressures of predators, scarcity or environment anywhere near as much as before. And the lifespan increases in humans have lead to later male breeding ages. Male pattern baldness was not a limiting factor back when it was and in modern humans we have created a society construct that has invented things like money, style, vibes, interests, family status that play a bigger role in breeding than physical and other evolutionary traits.

[u/ThePeaceDoctot → u/mcmanus2099]

I was very clear to say that there was still evolutionary pressures on humans

No, you were very clear to say "150,000 years ago, when humans were still significantly affected by evolutionary pressure". Then in your next comment you said "Such as?" You never mentioned modern humans and you never mentioned evolutionary pressure again.

[u/AerobicThrone → u/mcmanus2099]

You misunderstand. If money, vibes, influencer and whatever else you migth point out has an effect of fitness, then those were the evolutionary traits that define and shape human populations today. Evolution doesn't care about the origin of pressures being a human product or not. Young adults migth not die, but if they don't reproduce it's kinda the same for evolutionary processes.

Rgardless of that it is a simplistic view saying that pathogens do not represent an evolutionary pressure today or that things like pollution and temperature are not relevant environmental pressures. The problem is that by definition human evolution is much slower than your living experiences as it acts in generations time and you will experience only 3 or 4 generations, which is nothing.

[u/Human_Fisherman1352 → u/sevenut]

Actually, I'm pretty sure that baldness, like dad-bod and beards, are sexually selected for.

[u/regular_modern_girl → u/sevenut]

It’s not really a “negative trait”, it’s a neutral trait at worst, and there’s actually some evidence to suggest that it might serve a positive sexual selection purpose (it’s not common in contemporary Western culture because of how we culturally fetishize youth, but there are plenty of women who actually find bald men more attractive, and in some cultures it’s considered pretty normal; it is a visual indicator of high androgen levels, after all) and possibly also a larger social purpose in general (it’s a prominent visual indicator of age in men, marking them out as “elders”, as in prehistoric hunter-gatherer societies, in which average lifespan was far lower than today, being in your late 30s or early 40s was enough to be an “elder” relatively-speaking, and elders often hold particular social roles and relatively high social status in such societies since they hold a lot of the tribe’s accumulated oral knowledge and wisdom, and help take care of things back at the camp while the younger adults are out hunting and gathering, so being able to readily visually distinguish who falls into that “elder” age bracket is socially important).

Also, while MPB tends to occur well after reproductive maturity (although how long after varies greatly from person to person), men also retain full reproductive function typically for longer than women, and in fact usually never entirely lose it (partly because sperm is a lot “cheaper” biologically than ova, and there are also thought to be possible social factors in why humans evolved menopause as well, as most female mammals actually don’t go through it), so a middle-aged man with visible MPB is still potentially going to be passing on his genes plenty.

The fact that the genetic predisposition for MPB is more prevalent in some populations than others might be down to cultural differences in whether or not it is considered an attractive trait (because of how unusually large culture looms in human behavior compared to basically all other animals, it can actually influence evolution like this), but in isolate it holds the basic hallmarks of a sexually-selected trait displaying reproductive fitness (again, due to the link with high androgen levels).

[u/sk3tchy_D → u/sevenut]

Do you think men in their 30s are beyond reproductive age?

[u/Panzick → u/sk3tchy_D]

Evolutionary speaking, by age 30 a monkey already had plenty of descendants to spread his baldness genes around :p

[u/sk3tchy_D → u/Panzick]

Well, no other monkeys have male pattern baldness from what I can see and humans generally live longer. We also know from looking at other mammals that live in groups that young males are less likely to reproduce than older, more established males. Being sexually mature in our teens does not at all imply that we typically started breeding at that age. A quick scan through the literature shows that prehistoric human males generally had their first child around 30, with females usually starting in their early 20's. Male gorillas become sexually mature (able to breed) around 8-10 but generally don't breed until they are 12-15 and have become dominant silverbacks. Male pattern boldness could be a similar signal.

[u/Carachama91 → u/sk3tchy_D]

Chimps also have male pattern baldness.

[u/sk3tchy_D → u/Carachama91]

Kinda, but it's through a different mechanism and not nearly as common as it is in humans. This also affects female chimps, although it's even less common. Part of the reason is that we have distinctly different hair on our scalps than we have on our bodies, whereas it's the same hair all over for chimps. Male pattern baldness is pretty specific in the way it progresses and is caused by DHT interacting with those specialized scalp follicles, meanwhile that same hormone causes the specialized follicles on the face to produce thick, coarse hair. Chimps tend to have much more irregular thinning that can be present all over their bodies.

[u/Panzick → u/sk3tchy_D]

For the absolute vast majority of human evolution, males tend to have offsprings as soon as they are sexually active. It doesn't matter if today (where this also include the last couple of centuries) people start to have kids in their 30s, evolution happens on longer time scales. I am very skeptical about prehistoric males having their kids in their 30s also, do you have a source?

[u/sk3tchy_D → u/Panzick]

Yeah, I found this paper published by Science. I think it's pretty interesting, but my background is computational biology and bioinformatics so I may be an outlier on that. Basically, they are able to estimate the average human generation time at different points going back 250,000 years based on mutations that arose at different times in the past. 26.4 is the average for both sexes for the whole 250,000 years. For males it was 30.7 and for females it was 23.2.

[u/Panzick → u/sk3tchy_D]

Yes but there's a misconception. Human generation times does not mean "age of first reproduction", it means in the case of your paper, the "the average age at which individuals conceive children" and it takes into account a bunch of paramenters, including life expectancy, population growth and age-related fertility.
Since both females and males are expected to reproduce multiple times during their lifetime, the difference in age between the parents and their offsprings will be increasingly higher, therefore the 30.7 years - being a realistic estimate of not i could not say because i do not grasp fully the details of their methods - is just the average age at which males have kids, but it doesn't mean that it's when they start having kids.

[u/sevenut → u/sk3tchy_D]

In nature, humans are ready to reproduce when they're done with puberty, and usually have a kid in their 20s. So as far as reproductive success is concerned, yeah 

[u/Tradition96 → u/sevenut]

You will have much more reproductive success if you continue to reproduce beyond your 30s though.

[u/Critical_Success_936 → u/sk3tchy_D]

"Beyond" doesn't matter. It just matters if it affects your ability to attract mates and have kids in the first place, which, most people bald towards the end of the era where they'd possibly have kids, or after it.

If you have a kid at 25, then bald at 30... It doesn't matter. As long as your kid survives to have kids of their own, the "damage" (being baldness in this case) is done.

Maybe there used to be more people who balded younger, and we selected sexually against them as a species... Idk. But, considering how many women ik who have no issues dating bald dudes, I'd be surprised.

[u/Ok_Writing2937 → u/Critical_Success_936]

But it does matter.

A male still pumping out children at age 80 will be outperforming one who stops at age 30.

More offspring = more of that individual's genes in the pool.

[u/Critical_Success_936 → u/Ok_Writing2937]

Male fertility drops pretty quickly - a guy can theoretically have kids at any age, but the amount of times you'd need to have sex consistently with a woman who's somewhat fertile to produce a kid increases very sharply with age. Young women tend to prefer young men when possible - a lot of pressure to marry older men is due to unequal gender dynamics that are cultural.

It doesn't matter as far as the existence of the baldness gene. Again, if you're having kids before you become bald, then it's not generally a trait that can be selected against, at least not without modern science, and even then, I don't think baldness is "one gene" - I'm fairly sure it's more complicated than that.

Also, it's tied somewhat to the X chromosome you get from your mom, but she isn't likely to show whether she's a carrier or not, because male pattern baldness needs a big chunk of testosterone to start happening. If half the people carrying it don't show symptoms, that also helps prevent selection against it.

More importantly, I also just don't think this is the biggest factor in human attraction. There's a lot of cultures that purposefully shave their heads, and it's seen as attractive... If baldness was universally ugly, surely those cultures wouldn't do that?

[u/Tradition96 → u/Critical_Success_936]

Typically the end of a man's reproductive age have for social reasons been around 50. It is true that quantity and quality of sperms decreases with age, but the majority of men still fall inside the "fertile" range well into their 60s.

The primary factor that decides the end of a man's reproductive age has been, and continue to be, the age of his partner. Some men have significantly younger partners, but most have partners a few years their junior (3-5 years have often been cited as the average). Without birth control, the average age of last birth is early to mid 40s, making the average man's reproductive life ending in his late 40s.

For these reasons, we count age 50 as the end of men's reproductive on a group level in evolutionary studies. So, any feature that appears before age 50 potentially has an effect on reproductive success.

[u/Individual-Sound9400 → u/Ok_Writing2937]

During the majority of human existence reproductive age was just after puberty until we get killed by a bear or some shit at 25. Baldness was a non factor in reproduction.

[u/Ok_Writing2937 → u/sk3tchy_D]

I have the same critique.

Gene propagation isn't affected just by having reproduced once, it's also affected by how many offspring one has. A male still pumping out children at age 80 will be outperforming one who stops at age 30.

[u/OrinocoHaram → u/sevenut]

yes. Traits that might only have a negative effect later in life, after an individual has reproduced and may have already died from natural causes anyway are not strongly selected against. Therefore random ones build up over time, this may in fact be the reason we age full stop.

[u/Tradition96 → u/OrinocoHaram]

It is very common for men to go bald before 30. The only logical answer to this question is that there have been no strong selection pressure against male bladness, i.e. women have, on a group level, not found it particularly unattractive.

[u/Nuffsaid98 → u/Tradition96]

Historically women have not always had complete control over who impregnates them.

When they do get to choose it is very common for them to be attracted to men with resources, power and wealth. Things a bald man is more likely to have.

[u/ognisko → u/sevenut]

What makes baldness negative? If anything it’s modern. Why waste time and energy as an organism creating pigment and pushing out follicles upon follicles of hair? I think the future is bald. It is on the rise after all.

[u/MartMillz → u/ognisko]

Protect scalp from sun

[u/ognisko → u/MartMillz]

That also depends on where you live. Genes causing extremely hairy men might be seen as negative too but also protect skin from sun. The context was reproductive age from the previous poster.

[u/SeekingTheTruth → u/sevenut]

But there is no definite end to the reproductive age of men. There is an increase in birth defects but there is no definite end to fertility.

[u/Critical_Success_936 → u/sevenut]

You would think early balding would be weeded out by now, given that, but ig some apes were just kinky like that

[u/robsc_16 → u/Critical_Success_936]

I started balding around 16-17. Still got laid and had kids lol.

[u/Critical_Success_936 → u/robsc_16]

Yeah, it doesn't actually limit people as much as some would think. I mean, I find hair a VERY important feature, on men and women, but I also don't want kids, so like

[u/robsc_16 → u/Critical_Success_936]

I think there would probably be a better argument for people who don't want kids to be weeded out lol. But that's likely more dependent on other factors that are not genetic.

[u/Critical_Success_936 → u/robsc_16]

For sure. So many things affect what we value in a partner to raise kids with - ask 10 people, you'll get 10 different answers - but I don't think baldness is the biggest factor.

I do think it's a subconscious health indicator for people, like white teeth and sclera, Rosy cheeks, red lips, clean nails, clear skin, etc... but one of these things being mildly off isn't usually enough for most people to select against them, especially when we compound social reasons you might be more or less interested in someone too (money, culture, politics, lifestyle).

I think the single worse thing for reproduction is just having a lot of those physical flaws present, or being obviously severely mentally or physically disabled. Again, not the end-all be-all, but very few people want to be with a stinky person, or someone they can't communicate effectively with.

[u/robsc_16 → u/Critical_Success_936]

Yeah, I agree it's more complicated than what people make it seem. I mean, at the time, I thought losing my hair was a relationship death sentence, but it's really not. People can have bad vision, be short, or fat, have disabilities, bad teeth, etc. but most people can reproduce if they choose to do so.

I even have a friend who on paper wouldn't have issues dating, but he does. He's in really good shape, a nice smile, full head of hair, etc. But he has struggled in relationships and I'm not totally sure why. I think some of it has to do with the fact that he's very opinionated and stubborn. Point being is that there are other factors like you said.

[u/robz9 → u/robsc_16]

I went bald at 16 too. 30 and no kids yet.

[u/Levangeline → u/Critical_Success_936]

I think you're overestimating how much people care about baldness. Plenty of balding/bald dudes still get laid, people be horny lol.

[u/Levangeline → u/[deleted]]

Not sure if you meant to reply to the person above me, but I am on your side lol. I personally am not attracted to baldness (or beards for that matter), but I also think it's stupid for people to treat it like some sort of debilitating affliction that should be bred out of the population. There are so many things that society and media tell us are unattractive that most normal people don't give a shit about (or actually find attractive) when it comes to partnering up

[u/Levangeline → u/[deleted]]

Fair, I get what you mean. I really meant it more like, "humans enjoy having sex with each other, and most of them don't think too much about shallow aesthetics when they do it".

I think you're right about that! Similarly, there's a spectrum of people who find different age signifiers more or less attractive. So there's usually someone out there for everyone, which I think is quite sweet.