[Ecologist]

Hi there. A question came to my mind another day, and I decided to ask around so that I would know whether somebody studied this topic or not. I tried google, but thought it might be easier to try a forum. Here it goes.

Anal sex demands that the rectum is large enough to accommodate the penis. Because it is a so widespread practice, for example, see inmates in prisons, ordinary couples, etc., I suppose it has accompanied the human race since it beginnings. It seems, also, that that "ice man" found in Europe and that lived some 5,000 years ago had sperm in his rectum, which proves that he was either gay or raped.

Then, I think that in the early past of the human race, it may have happened that rectum might have been smaller, and natural selection operated so that only people with large enough rectum would pass its genes forward.

Is there any basis on what I am saying? Thank you for any contribution.

[ajb]

Ecologist, on 4 February 2012 - 09:22 PM, said:

It seems, also, that that "ice man" found in Europe and that lived some 5,000 years ago had sperm in his rectum, which proves that he was either gay or raped.

Has that been substantiated? You sure that is not just some weird internet rumour?

[Ringer]

Since the anus and rectum are able to be stretched it would not be necessary to have a initially large rectum for anal sex. Also, selection wouldn't select for more anal sex because it doesn't affect reproduction in a positive way. As to why anal sex seems to be prevalent, it seems to have more to do with things like lack of sexual partners, dominance, sometimes bonding, and how people enjoy trying different things.

An assumption about sexual preferences, as far as things like anal and sexual positions, being selected for are usually flawed because it assumes that natural selection is acting on anything more than just having sex, i.e. why would masturbation be selected for.

[edit] The cave man thing was an April Fools joke. [/edit]

This post has been edited by Ringer: 4 February 2012 - 10:37 PM

[John Cuthber]

My guess is that it's true that " it has accompanied the human race since it beginnings." but I think you are mistaking cause for effect.
As a species we seem remarkably imaginative about where we put our dicks. If our ears were big enough we would probably screw them too.

The size of the rectum is going to be pretty much determined by it's primary function.
Anal sex has nothing much to do with procreation so it's not a trait that evolution will be interested in. (If anything it is selected against)

[iNow]

Ecologist, on 4 February 2012 - 09:22 PM, said:

Then, I think that in the early past of the human race, it may have happened that rectum might have been smaller, and natural selection operated so that only people with large enough rectum would pass its genes forward.

Is there any basis on what I am saying? Thank you for any contribution.

In what way do you propose that rectum size influences the likelihood of a sperm hitting an egg in a member of the opposite sex? If two guys are having anal sex, regardless of the size of their rectums, there is nothing to get selected for... Basically, you've made this assumption without explaining what the selection pressure would be that influenced this.

I'm sure there are ancient humans who have had same sex intercourse. There are also countless non-human animals (in fact, homosexual behavior has been observed in every animal we've studied). Even with that said, though, rectum size has no influence on the likelihood of future offspring, nor does the act of having anal sex (whether with a female or male partner)... except maybe to decrease the chances of having any offspring since the sperm is not being injected into a fertile uterus.

[Ecologist]

Thanks everyone for sharing your thoughts. Yes, now I see that my original idea was probably flawed. Maybe I will start thinking about other things that shaped human evolution. Or about anal sex, I don't know. Let's see. Cheers!

[ajb]

Ecologist, on 5 February 2012 - 09:08 PM, said:

Thanks everyone for sharing your thoughts. Yes, now I see that my original idea was probably flawed. Maybe I will start thinking about other things that shaped human evolution. Or about anal sex, I don't know. Let's see. Cheers!

Whatever you do make sure you enjoy it

[Santalum]

iNow, on 5 February 2012 - 04:12 PM, said:

In what way do you propose that rectum size influences the likelihood of a sperm hitting an egg in a member of the opposite sex? If two guys are having anal sex, regardless of the size of their rectums, there is nothing to get selected for... Basically, you've made this assumption without explaining what the selection pressure would be that influenced this.

I'm sure there are ancient humans who have had same sex intercourse. There are also countless non-human animals (in fact, homosexual behavior has been observed in every animal we've studied). Even with that said, though, rectum size has no influence on the likelihood of future offspring, nor does the act of having anal sex (whether with a female or male partner)... except maybe to decrease the chances of having any offspring since the sperm is not being injected into a fertile uterus.

I should point out that chimpanzees exhibit similar sorts of bevaiour among males. If a female is not available then a dominant male is just as likely to bum rape the nearest subordinate male in order to sate his urge. I remember seeing this in a documentary about apes/chimps at some point.

But here is a reference from Wikipedia anyway:

Quote

Bonobo and other apes


Bonobo

The <A title=Bonobo href="http://en.wikipedia.org/wiki/Bonobo">Bonobo, which has a <A title=Matriarchy href="http://en.wikipedia.org/wiki/Matriarchy">matriarchal society, unusual amongst <A title=Ape href="http://en.wikipedia.org/wiki/Ape">apes, is a fully <A class=mw-redirect title=Bisexual href="http://en.wikipedia.org/wiki/Bisexual">bisexual species—both males and females engage in heterosexual and homosexual behavior, being noted for female-female homosexuality in particular. About 60% of all sexual activity in this species is between two or more females. While the homosexual bonding system in Bonobos represents the highest frequency of homosexuality known in any species, homosexuality has been reported for all <A class=mw-redirect title="Great apes" href="http://en.wikipedia.org/wiki/Great_apes">great apes (a group which includes <A title=Human href="http://en.wikipedia.org/wiki/Human">humans), as well as a number of other <A title=Primate href="http://en.wikipedia.org/wiki/Primate">primate species.^{<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-penisfencing-55">[56]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-autogenerated3-56">[57]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-ancestor-57">[58]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-songweaver-58">[59]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-59">[60]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-60">[61]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-61">[62]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-62">[63]<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-63">[64]} Dutch <A class=mw-redirect title=Primatologist href="http://en.wikipedia.org/wiki/Primatologist">primatologist <A title="Frans de Waal" href="http://en.wikipedia.org/wiki/Frans_de_Waal">Frans de Waal on observing and filming bonobos noted that there were two reasons to believe sexual activity is the bonobo's answer to avoiding conflict.

Anything that arouses the interest of more than one bonobo at a time, not just food, tends to result in sexual contact. If two bonobos approach a cardboard box thrown into their enclosure, they will briefly mount each other before playing with the box. Such situations lead to squabbles in most other species. But bonobos are quite tolerant, perhaps because they use sex to divert attention and to defuse tension.

Bonobo sex often occurs in aggressive contexts totally unrelated to food. A jealous male might chase another away from a female, after which the two males reunite and engage in <A title=Scrotum href="http://en.wikipedia.org/wiki/Scrotum">scrotal rubbing. Or after a female hits a juvenile, the latter's mother may lunge at the aggressor, an action that is immediately followed by genital rubbing between the two adults.^{<A href="http://en.wikipedia.org/wiki/Homosexual_behavior_in_animals#cite_note-64">[65]}

This post has been edited by Santalum: 6 February 2012 - 12:19 AM

[iNow]

Yes, it's known to calm tensions with an aggressive alpha male, and is a type of subordination in many species that exist in troops like humans and bonobos. That would not impact selection of smaller rectum holes, though.

[StringJunky]

Has a couple or more Bonobos ever been separated from another group at birth such that they couldn't have learnt this behaviour and do they still exhibit this sexually appeasing behaviour between themselves as they grow up in isolation? Hope that makes sense. I'm wondering if it's a learnt custom or instinctual.

This post has been edited by StringJunky: 6 February 2012 - 01:49 AM

[Santalum]

StringJunky, on 6 February 2012 - 01:48 AM, said:

Has a couple or more Bonobos ever been separated from another group at birth such that they couldn't have learnt this behaviour and do they still exhibit this sexually appeasing behaviour between themselves as they grow up in isolation? Hope that makes sense. I'm wondering if it's a learnt custom or instinctual.

I would imagine the behaviour among apes would be similar to that between humans in that there is a whole spectrum of reasons why they engage in the behaviour, including sexual attraction to the same sex.

[StringJunky]

Santalum, on 6 February 2012 - 01:53 AM, said:

I would imagine the behaviour among apes would be similar to that between humans in that there is a whole spectrum of reasons why they engage in the behaviour, including sexual attraction to the same sex.

Bonobos, IIRC, are completely indiscriminate in which members they will engage sexually with regardless of age, gender or familial connection...there are no taboos. They seem to be quite unique amongst apes in this respect. I wondered how sexually 'amoral' they would be in the absence of a learning environment amongst already practising Bonobos.

[iNow]

The sex drive and the tendency to be submissive toward aggressive alpha males are more genetically linked, AFAIK. The expression of those tendencies is the taught part.

Separate, but related: http://www.sciencefo...animal-kingdom/

[Anders Hoveland]

About those Bonobos, this has also been observed amongst traditional humans in Africa:

Zulu chiefs and military leaders traditionally engaged in homosexual "thigh-thrusting" with their subordinates or troops to "create intimacy and loyalty".


"Boy Wives": Age-differentiated Homosexuality

In the central African Zande culture, before European conquest, it was regarded "as very sensible for a man to sleep with boys when women are not available or are taboo." English anthropologist E. E. Evans-Pritchard was told that in addition to times when women were not available for sex, some Azande men had sex with boys "just because they like them."

The adult males paid the families of boy wives, just as they paid for female brides. The two slept together at night, "the husband satisfying his desires between the boy's thighs. When the boy grew up he joined the company and took a boy-wife in his turn. It was the duty of the husband to give his boy-wife a spear and a shield when he became a warrior. He then took a new boy-wife."

One commander, Ganga, told Evans-Pritchard that there were some men who, although they had female wives, still married boys. "When a war broke out, they took their boys with them. . . . If another man had relations with his boy, the husband could sue the interloper in court for adultery."

The South African Thonga provide another particularly well-documented instance of a boy-wife role. A number of southern and western African societies also had female "husbands".


King Mswati Unsuccessfully Attempts to RAPE a Bull
In the picture below, King Mswati (of Swaziland) be seen next to Robert Mugabe (president/dictator of Zimbabwe), who was invited to witness part of the "ritual".

Quote

"Among its highlights is a symbolic demonstration by the king of his power and dominance in a process involving his penetration of a black bull, beaten into semi-conscious immobility to ensure its compliant acceptance of the royal touch. The royal semen is then collected by a courtier and stored, for subsequent inclusion in food to be served at Sibaya – traditional councils – and other national forums. ... But last year’s selected bull, according to a recent account from a whistle-blowing Incwala initiate, objected strongly, and threw off Africa’s last absolute monarch."

You can read the full report of how King Mswati III tried to rape a bull (not a cow) at this link:
http://nehandaradio....ex-with-a-bull/