Monogamy Killed Men's Penis Bone

Mon, 12/19/2016 - 08:53
Submitted by bila kolbe

Among the many popular names penned to the penis like dick, cock, dong, pecker, and schlong, one that sticks out is undoubtedly the term ‘boner’. Yep, once a flaccid penis gets engorged with blood and dramatically stiffens, the boner takes on the rigidity and feels nothing less than a good chunk of solid bone. However, there is no actual bone material found in its anatomy unless of course you are a male chimp, bear, gorilla, dog, sea lion, rabbit, mouse, or weasel to name a few of those that happen to be endowed with a penis bone called a baculum or os penis.

The baculum is generally kept in the male’s abdomen until it is required, at which point abdominal muscles push it out into the penis, thus causing a quick and effective erection. Sliding a handy stiff bone into the fleshy penis is much easier and more reliable than waiting for the penis to fill with enough blood to maintain an erection long enough to deposit sperm into a female. This erectile speed is of real importance in many species, as mating often has to be quick and opportunistic.

An alpha male lion’s baculum, for instance, allows him to engage in an impressive 250 copulations in four days(an average of 62 per day!). Such a sexual marathon is highly unusual and easily justifies why these dudes are revered as the stud kings of the savannah.

Recent research has revealed an interesting difference in the penis bones of promiscuous house mice when compared to their monogamous counterparts. After breeding 27 generations of mice, the libertine Casanovas had evolved thicker baculums while the homebodies had thinner ones.

The mice equipped with wider baculums also produced more pups than other males. Some scientists have suggested that by making the penis rigid, the baculum lets a male deliver more sperm into a female. Those extra sperm may outnumber those of rival males. Others have suggested that the baculum helps the sperm travel further towards an egg. Still others have proposed that it stimulates the female, triggering ovulation.

Humans supposedly lost the penis bone along our evolutionary journey because of the onset of monogamy in our social mating behavior. Males started to exclusively accompany one female and engage in frequent rapid copulations to ensure the paternity of her children. Conversely, many macho animals face stiff competition to mate with females in estrus(heat). Once connected in coitus, they jealously engage in longer periods of copulation aided by a baculum which helps a male to guard a female from mating with any competitors, increasing his chances of passing on his genetic material.

There is also a female version of the baculum in some species which has a rather lovely name – the “baubellum”, or “os clitoris”. While very little research has been done in this area as well, it seems to be generally accepted that the baubellum (which means “little gem” in Latin) is essentially a bone found in the clitoris whose function remains a mystery. The os clitoris has been found in mice, marmots, seals, cats, bats, bears, squirrels, gibbons, and other animals. One study did uncover a unique connection between a sex hormone and development of the clit bone. Testosterone injections during the early days of life caused female rats to grow a larger os clitoris which closely resembles the male counterpart. Interestingly, testosterone is nowadays used to induce clitoral enlargement as a form of human female genital body modification.

So it appears that quickies with one mate eventually decommissioned the need for having a penis bone and maybe even one for the clitoris so that now we are left to rely on blood pressure and flow to perk up a limp dick or clit. No need to pine, we’re not alone in this depravity given that horses, whales, elephants, rhinos, and a slew of other well-hung animals get boners without a penis bone nor do the females carry a clit bone. Nevertheless, even though humans don’t wield a ‘bona-fide’ os penis or os clitoris, we still conserve in our language remnants of baculum power.

Argumentum ad baculum is Latin for ‘argument to the stick’ and means that an arguer threatens his/her debate opponent with real or threatened violent or nonviolent coercion. Consider Trump’s braggadocio about his penis size in response to Rubio’s insult comedy shtick during a GOP debate and stalking Clinton during the Presidential debates. Geez, maybe the Donald is one of those rare men with an actual os penis since he is often seen as a ‘smirking chimp’.

love, health, music, sex

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Tue, 12/20/2016 - 12:49
Heather1980 (not verified)

Interesting, but doesn't this research assume men have been monogamous for millions of years? As we know, monogamy is touted as the ideal but throughout history there have been harems, polygamy, mistresses, or in other words all varities of non-monogamy. Could it be men lost the bone when they began to walk upright? None of the animals mentioned walk upright exclusively. Also human women are the only ones that menstruate, and don't seasonally go into estrus, I think that may have played a part as well.

Advent of monogamy around 18,000 years ago, 600 generations ago.

Wed, 12/21/2016 - 22:17
bila kolbe

Heather, you bring up several good points; however, I'm not sure whether the research necessarily assumes monogamy has been around for millions of years or whether it would take millions of years for the penis bone to disappear from male anatomy. In fact, while researching the baculum, I didn't find any specific reference to any archaeological remains of hominids or Homo sapiens ever having a penis bone. Homo appeared 83,000 generations ago(2.5 million years ago)and Homo sapiens appeared 5,300 generations ago(160,000 years ago). Some genetic research indicates the advent of monogamy at about 18,000 years ago (about 600 generations)when agriculture was shaping human social behavior.  A lot of this research on the penis bone is more based on archaeological and contemporary studies of particular mammalian species exhibiting the presence of a baculum and how variances in sexual behavior over generations affects its physiology. From this, researchers apparently assume early humans had a penis bone which might have helped augment early populations via frequent random matings. Then with the beginnings of agriculture, mongamy, and less polygynous competition, the penis bone may have become more of a burden than an asset. I think your alternate explanations incorporating the advent of walking upright and the human female reproductive cycle are worthy of consideration and further research. Thanks for giving this topic some viable alternate perspectives.


Thu, 12/22/2016 - 02:07

The research seems to suggest that the baculum allows for prolonged penetration rather than ejaculation, which could be useful in societies where as soon as one male finishes, another jumps on top and tries to impregnate the female. It seems more of a "dog-in-the-manger" strategy ie. keeping the female locked to her current partner, rather than anything else and of course says nothing about pleasure. If we see the development of a static agricultural society as one where women and their fertility were more closely controlled, where paternity was recognised and tied to inheritance, then it's easy to see how the scientists could theorise that social controls were able to replace the physical "lock and key" penetration of the baculum.

But it's always a bit dangerous to extrapolate from animal behaviour to human and vice versa. At university I remember a biologist dumfounded by the behaviour of mice. He had assumed the "big" virile male mouse had strong-armed his way to a large successful harem of submissive females that he dominated. In fact, whilst the male mice fought each other for the best nesting sites, the females moved around the location trying out the males, their nesting sites but also their sexual prowess, before settling on the "best" to have their litter. The female mice were rather choosy and fickle in their affections and moved around the males quite freely. It seemed to my friend that the male mice had a rather precarious "dominance" if any at all. 

What a great article, evloutionary biology can be fun

martiB's picture
Fri, 12/23/2016 - 12:03

So much for those limp-dick evolution deniers ;o)

[=black; line-height: 115%]I believe the blurring between, the equating love with sex, has done so much to dampen our sexual desire and sexual satisfaction.  Perhaps that's why those who can separate the two and enjoy both, in their own right, have so much more sex and get so much more pleasure from it. I'm speaking, of course, of the swingers, the many couples in open relationships, lovers in alternative relationships such as polyamory, gay men who generally live a far more sexual lifestyle. Such men engage in far more sex and with far more variety than the average str8 laced man in a traditional relationship and they also allow themselves to masturbate more. They are members of that highly sought after percent of the most sexually satisfied among us.[/]

[=black; line-height: 115%]And I can tell you, such men become far more sexually capable and their need and pleasure grows immensely. My own husband certainly has since we opened up our relationship, at my urgent request.
Although my desire for this was driven by my own need and pleasure, I think he has benefited most. He has become such an ejaculator.[/]

[=black; line-height: 115%]If such couples who have such a desire for more sex stayed together and produced offspring and then they stayed together and produced offspring, I am certain that we would have men with evolutionary advantages in their penis such as this. Larger, more responsive, and more quick to regenerate.  [/]I would love to see that.