Humans lose bone because we bone too quickly

Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you:

No adverts like this in the forums anymore.
Times and dates in your local timezone.
Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance.
Email notifications for threads you want to watch closely.
Being a part of the oldest wargaming community on the net.

If you are already a member then feel free to login now.

**A Town Called Malus**

https://www.theguardian.com/science/2016/dec/14/why-dont-humans-have-a-penis-bone-scientists-may-now-know-baculum

Why don't humans have a penis bone?
Scientists may now know

Speed of human mating might be behind the lack of a baculum in humans, suggests study tracing bone’s evolution

It can be as long as a finger in a monkey. In the walrus, it can be two feet long. But the human male has lost it completely. And researchers are a little stumped.

Known as the baculum to scientists with an interest, the penis bone is a marvel of evolution. It pops up in mammals and primates around the world, but varies so much in terms of length and whether it is present at all, that it is described as the most diverse bone ever to exist.

Prompted by the extraordinary differences in penis bone length found in the animal kingdom, scientists set out to reconstruct the evolutionary story of the baculum, by tracing its appearance in mammals and primates throughout history.

They found that the penis bone evolved in mammals more than 95 million years ago and was present in the first primates that emerged about 50 million years ago. From that moment on, the baculum became larger in some animals and smaller in others. The stump-tailed macaque, an animal that weighs only 10kg, has an extremely long baculum for its size, with the bone extending for 5cm. The bone is five times the size of the baculum in the collared mangabey, which is a slightly larger monkey.

Kit Opie who ran the study with Matilda Brindle at University College London, said that penis bone length was longer in males that engaged in what he called “prolonged intromission.” In plain English, that means that the act of penetration lasts for more than three minutes, a strategy that helps the male impregnate the female while keeping her away from competing males. The penis bone, which attaches at the tip of the penis rather than the base, provides structural support for male animals that engage in prolonged intromission.

In chimps, the penis bone is no longer than a human fingernail. The tininess of the bone correlates with the very short spell that the male spends mating, in the order of seven seconds. In chimpanzee groups, females mate with all the males, in what appears to be a strategy to reduce the risk of her children being killed by older males. “It gives each male an idea that they may have fathered the subsequent offspring, and it is in her interests to get that done quickly,” Opie said.

Humans may have lost their penis bones when monogamy emerged as the dominant reproductive strategy during the time of Homo erectus about 1.9 million years ago, the scientists believe. In monogamous relationships, the male does not need to spend a long time penetrating the female, because she is not likely to be leapt upon by other amorous males. That, at least, is the theory.

“We think that is when the human baculum would have disappeared because the mating system changed at that point,” Opie said. “This may have been the final nail in the coffin for the already diminished baculum, which was then lost in ancestral humans.” Details of the research are published in Proceedings of the Royal Society.

“With the reduced competition for mates, you are less likely to need a baculum,” he added. “Despite what we might want to think, we are actually one of the species that comes in below the three minute cut-off where these things come in handy.”

*Insert witty comment about premature emission here*

**Tannhauser42**

I would love to have been a fly on the wall when that research was going, just to see how long the various scientists involved could go between giggles.

**A Town Called Malus**

Indeed

Also, this research clearly proves that if you don't use it, you lose it

**Tannhauser42**

I bet they managed to run through every possible euphemism for "penis" and "erection" on the very first day.

**BigWaaagh**

So, if I'm reading this correctly, when someone says "You're boned!", it's not necessarily so.

**jmurph**

From a behavioral perspective, this theory makes no sense. They correlate longer baculum length with longer mating times but ignore that by the standards presented, humans have immensely long copulation periods- 3 minutes at the top end is embarrassingly fast for most human males. Yet humans have no baculum. Given that both chimps and gorillas have very small baculums, it seems to be a trait of certainly evolutionary paths. Indeed, since humans reply completely on hydraulic function, it may be that selection favored healthier humans or that it was a hindrance in human mating patterns. Or maybe it just never developed. It is not a ubiquitous feature-rabbits, elephants, dolphins, etc. also lack baculum. Interestingly, elephants and dolphins are also highly intelligent, highly social animals.

**NinthMusketeer**

A Town Called Malus wrote:
https://www.theguardian.com/science/2016/dec/14/why-dont-humans-have-a-penis-bone-scientists-may-now-know-baculum

Why don't humans have a penis bone?
Scientists may now know

Speed of human mating might be behind the lack of a baculum in humans, suggests study tracing bone’s evolution

It can be as long as a finger in a monkey. In the walrus, it can be two feet long. But the human male has lost it completely. And researchers are a little stumped.

Known as the baculum to scientists with an interest, the penis bone is a marvel of evolution. It pops up in mammals and primates around the world, but varies so much in terms of length and whether it is present at all, that it is described as the most diverse bone ever to exist.

Prompted by the extraordinary differences in penis bone length found in the animal kingdom, scientists set out to reconstruct the evolutionary story of the baculum, by tracing its appearance in mammals and primates throughout history.

They found that the penis bone evolved in mammals more than 95 million years ago and was present in the first primates that emerged about 50 million years ago. From that moment on, the baculum became larger in some animals and smaller in others. The stump-tailed macaque, an animal that weighs only 10kg, has an extremely long baculum for its size, with the bone extending for 5cm. The bone is five times the size of the baculum in the collared mangabey, which is a slightly larger monkey.

Kit Opie who ran the study with Matilda Brindle at University College London, said that penis bone length was longer in males that engaged in what he called “prolonged intromission.” In plain English, that means that the act of penetration lasts for more than three minutes, a strategy that helps the male impregnate the female while keeping her away from competing males. The penis bone, which attaches at the tip of the penis rather than the base, provides structural support for male animals that engage in prolonged intromission.

In chimps, the penis bone is no longer than a human fingernail. The tininess of the bone correlates with the very short spell that the male spends mating, in the order of seven seconds. In chimpanzee groups, females mate with all the males, in what appears to be a strategy to reduce the risk of her children being killed by older males. “It gives each male an idea that they may have fathered the subsequent offspring, and it is in her interests to get that done quickly,” Opie said.

Humans may have lost their penis bones when monogamy emerged as the dominant reproductive strategy during the time of Homo erectus about 1.9 million years ago, the scientists believe. In monogamous relationships, the male does not need to spend a long time penetrating the female, because she is not likely to be leapt upon by other amorous males. That, at least, is the theory.

“We think that is when the human baculum would have disappeared because the mating system changed at that point,” Opie said. “This may have been the final nail in the coffin for the already diminished baculum, which was then lost in ancestral humans.” Details of the research are published in Proceedings of the Royal Society.

“With the reduced competition for mates, you are less likely to need a baculum,” he added. “Despite what we might want to think, we are actually one of the species that comes in below the three minute cut-off where these things come in handy.”

I believe these scientists have gotten to a premature conclusion.

Wish granted!

**Silent Puffin?**

jmurph wrote:
From a behavioral perspective, this theory makes no sense. They correlate longer baculum length with longer mating times but ignore that by the standards presented, humans have immensely long copulation periods- 3 minutes at the top end is embarrassingly fast for most human males. Yet humans have no baculum. Given that both chimps and gorillas have very small baculums, it seems to be a trait of certainly evolutionary paths. Indeed, since humans reply completely on hydraulic function, it may be that selection favored healthier humans or that it was a hindrance in human mating patterns. Or maybe it just never developed. It is not a ubiquitous feature-rabbits, elephants, dolphins, etc. also lack baculum. Interestingly, elephants and dolphins are also highly intelligent, highly social animals.

Indeed, the given hypothesis sounds very thin.

I prefer Richard Dawkin's hypothesis; that the loss of the bone was due to sexual selection. As only healthy males can maintain an erection without a baculum, females have a better idea of who is a good mate. As ideas go its still a little limp though

**Nostromodamus**

Leave it to a bunch of nerds to think it only takes 3 minutes...

**General Annoyance**

Of course you'd be behind a thread like this, Malus

This must make anyone who can't last for more than 3 minutes feel a lot better about themselves... although explaining science to your partner post coitus is hardly going to help

**AegisGrimm**

Under three minutes? Wow, sucks for a bunch of women involved in that research....

**A Town Called Malus**

jmurph wrote:
From a behavioral perspective, this theory makes no sense. They correlate longer baculum length with longer mating times but ignore that by the standards presented, humans have immensely long copulation periods- 3 minutes at the top end is embarrassingly fast for most human males. Yet humans have no baculum. Given that both chimps and gorillas have very small baculums, it seems to be a trait of certainly evolutionary paths. Indeed, since humans reply completely on hydraulic function, it may be that selection favored healthier humans or that it was a hindrance in human mating patterns. Or maybe it just never developed. It is not a ubiquitous feature-rabbits, elephants, dolphins, etc. also lack baculum. Interestingly, elephants and dolphins are also highly intelligent, highly social animals.

Humans have longer mating times now but it isn't as if we lost our baculum overnight. That longer mating time has come about not from some arbitrary bit of biology but more from a change in the role of sex in our society where it became no longer purely an act of reproduction but also an act of fun, especially as our mental capacities developed. These are changes we can also observe in other animals in nature, such as Chimps and Dolphins.

**LordofHats**

jmurph wrote:
From a behavioral perspective, this theory makes no sense. They correlate longer baculum length with longer mating times but ignore that by the standards presented, humans have immensely long copulation periods- 3 minutes at the top end is embarrassingly fast for most human males.

I think they're talking more about the time it takes to complete the act biologically, not how long it takes to make it really fun

**Nostromodamus**

A Town Called Malus wrote:
These are changes we can also observe in other animals in nature, such as Chimps and Dolphins.

Whatever floats your boat...

**Farseer Anath'lan**

Also not raised, is that monogamy (in the sense most people think of) isn't really that widely prevalent-in developing and tribal areas polygamy is more widely spread. So how does that factor into the conclusion, unless they're using monogamy in the sense that women only have 1 partner, while the male may have multiple partners? That's a weird definition of monogamy.

**Silent Puffin?**

A Town Called Malus wrote:
That longer mating time has come about not from some arbitrary bit of biology but more from a change in the role of sex in our society where it became no longer purely an act of reproduction but also an act of fun, especially as our mental capacities developed.

Good luck finding evidence for that....

**sebster**

Hang on, what? We're not supposed to have a bone in it?

:looks down:

Hmm...

**Skinnereal**

In it or through it?

**jmurph**

Silent Puffin? wrote:
A Town Called Malus wrote:
That longer mating time has come about not from some arbitrary bit of biology but more from a change in the role of sex in our society where it became no longer purely an act of reproduction but also an act of fun, especially as our mental capacities developed.

Good luck finding evidence for that....

Yeah, humans have been engaging in sexual activity for pleasure for at least as long as they have been scribbling on things. It's far from a unique behavior, and is present in other primate and non-primate species. As to developing mental capacity, there is no real evidence that has increased. In fact, we may be "dumber" than our hunter gatherer ancestors in terms of innovation and problem solving. Though we have access to more stored information, there is no indication that our memory, problems, solving, or other mental faculties has shown any improvement as a species. Ironically, we may have become dependent on our own success!

On thing that is interesting about the baculum is that it seems to be a case of parallel evolution and definitely is not universal. It may be that the human evolutionary track never had much of one to speak of, not that we lost it. Or, it is so far back in our evolutionary path that we were never "humans" when we had it.

**Pouncey**

Cool. That's a nifty news article.

What does the study itself say, though?

Automatically Appended Next Post:

jmurph wrote:
Silent Puffin? wrote:
A Town Called Malus wrote:
That longer mating time has come about not from some arbitrary bit of biology but more from a change in the role of sex in our society where it became no longer purely an act of reproduction but also an act of fun, especially as our mental capacities developed.

Good luck finding evidence for that....

Yeah, humans have been engaging in sexual activity for pleasure for at least as long as they have been scribbling on things. It's far from a unique behavior, and is present in other primate and non-primate species. As to developing mental capacity, there is no real evidence that has increased. In fact, we may be "dumber" than our hunter gatherer ancestors in terms of innovation and problem solving. Though we have access to more stored information, there is no indication that our memory, problems, solving, or other mental faculties has shown any improvement as a species. Ironically, we may have become dependent on our own success!

On thing that is interesting about the baculum is that it seems to be a case of parallel evolution and definitely is not universal. It may be that the human evolutionary track never had much of one to speak of, not that we lost it. Or, it is so far back in our evolutionary path that we were never "humans" when we had it.

Well, yeah, of course humans have sex for pleasure. We have no fixed mating season, and no way to determine when women are ovulating. Our reproduction method thus needed a way to ensure we'd keep doing it despite not knowing when the best time would be to produce offspring, and thus we have a sex drive and the pleasure of sex to ensure we do it as much as possible.

It's worth noting though, that the powerful human brain, like a great many of our bizarre traits, developed purely as a result of sexual selection - we find intelligence and creativity attractive in our mates, thus those traits get enhanced over many generations, like how a peacock's plumage developed. In my personal opinion, humans still find intelligence and creativity attractive, and stupidity not, thus our intelligence will likely continue to develop as our evolution goes on.

Our brains are likely still getting better, it's just that our modern technology allows us to eschew developing things like a skilled memory. I guess you could equate it to a physically powerful species that becomes lethargic and their muscles simply atrophy.

Automatically Appended Next Post:

A Town Called Malus wrote:
Indeed

Also, this research clearly proves that if you don't use it, you lose it

Vestigial organs are a thing.

**treslibras**

Pouncey wrote:
In my personal opinion, humans still find intelligence and creativity attractive, and stupidity not, thus our intelligence will likely continue to develop as our evolution goes on.

Our brains are likely still getting better, it's just that our modern technology allows us to eschew developing things like a skilled memory. I guess you could equate it to a physically powerful species that becomes lethargic and their muscles simply atrophy.

To have evolution you also need evolutionary pressure (direct advantage of mutations in a changing ecological niche) and small populations.
Since that is no longer the case for most mutations other than those effectively and exproportionally raising your chance of survival (e.g. the rise of the sickle-cell disease in malaria-ridden regions), and unless world populations become a lot less interconnected again (EDIT: and then a lot more connected again afterwards), we will see very few human evolution on a global level. Even if brains with less influence of the cerebellum vs. cerebral cortex become a thing in Switzerland, the advantage would bot be big enough to make a global impact, where reduced "animal instincts" might be an actual disadvantage.

But after WW3 - who knows?

**NinthMusketeer**

Yeah, evolution doesn't work in modern human societies. The only intelligence trend that does exist is actually humans getting dumber -- because people with less intelligence statistically have more children. That's the basis of 'Idiocracy' ideas, which are good for movies but in reality it ignores the fact that people don't hook up at random.

**Silent Puffin?**

NinthMusketeer wrote:
The only intelligence trend that does exist is actually humans getting dumber -- because people with less intelligence statistically have more children.

Not less intelligence, less education. That does not mean that they are less intelligent and its an unfortunately common and pernicious belief that the poor are 'dumb'.

Evolution does work in modern human societies, evolution is always 'on' although as our life styles (in terms of biological and ecological threat and reproduction) are now much more managed big evolutionary changes will take much longer to appear than they would otherwise, this is especially true due to the global nature of modern society. Of course there is always the aftermath of WWIII and evolution is still very much alive in parts of the world without secure food supplies and advanced medicine.

**NinthMusketeer**

Silent Puffin? wrote:
NinthMusketeer wrote:
The only intelligence trend that does exist is actually humans getting dumber -- because people with less intelligence statistically have more children.

Not less intelligence, less education. That does not mean that they are less intelligent and its an unfortunately common and pernicious belief that the poor are 'dumb'.

I agree, yet the less intelligent also trend to be less educated and less economically well off. But I don't mean to say its an overwhelming majority by any means; there are huge numbers of intelligent uneducated people, intelligent poor people, stupid as gak rich people, and everything in between.

**AegisGrimm**

Modern human society, for better and for worse, has nearly eliminated natural selection, really. So evolution is now basically reliant on random mutation alone for anything that counts as short-term as evolution measures things.

**NinthMusketeer**

See back in the day all the donkey-caves were kicked out of the tribe (and eaten by sabertooths) while the idiots were trampled in the daily mammoth hunt! Now us young'uns have screwed it all up.

**godardc**

NinthMusketeer wrote:
Silent Puffin? wrote:
NinthMusketeer wrote:
The only intelligence trend that does exist is actually humans getting dumber -- because people with less intelligence statistically have more children.

Not less intelligence, less education. That does not mean that they are less intelligent and its an unfortunately common and pernicious belief that the poor are 'dumb'.
I agree, yet the less intelligent also trend to be less educated and less economically well off. But I don't mean to say its an overwhelming majority by any means; there are huge numbers of intelligent uneducated people, intelligent poor people, stupid as gak rich people, and everything in between.

I had never thought about it. It sounds a bit scary said like this, but it isn't false. Very sad

**jmurph**

godardc wrote:
NinthMusketeer wrote:
Silent Puffin? wrote:
NinthMusketeer wrote:
The only intelligence trend that does exist is actually humans getting dumber -- because people with less intelligence statistically have more children.

Not less intelligence, less education. That does not mean that they are less intelligent and its an unfortunately common and pernicious belief that the poor are 'dumb'.
I agree, yet the less intelligent also trend to be less educated and less economically well off. But I don't mean to say its an overwhelming majority by any means; there are huge numbers of intelligent uneducated people, intelligent poor people, stupid as gak rich people, and everything in between.

I had never thought about it. It sounds a bit scary said like this, but it isn't false. Very sad

I don't know that it particularly accurate, however. Economic position is largely determined by heritable wealth. The largest determinant in economic condition is birth. Born wealthy, and you are likely to be wealthy; born poor, odds are you stay poor. And this has been true throughout history. Historically, wealth is acquired by those with the power to secure resources and maintain them, often by force.