Human penis-shape and sperm competition


I know they were just dildos, but the talk of chopping and filing with an Emory board still gave me the willies.


hehe, willies.


Mines out of shape. I think it needs to exercise more.

1 Like

The authors note that their on-campus surveys found that 12 percent of the students polled had had sex with multiple men in a 24 hour period and hypothesized that an evolutionary function of the glans is to force out the semen left by earlier partners prior to ejaculation.

This sentence just does not compute for me. 12 per cent of women had had sex with multiple men in a 24 hour period, so therefore the penis serves this evolutionary function?

1 Like

The artificial vagina seems like a weak point in the experiment. I don’t think a real vagina where the tissues engorge and where the elastic mechanism is different would necessarily behave the same way.

Still: Finally! I got really sick and tired of evolutionary conjecture about this subject getting passed off as fact when no one could point to any experiments done on the subject.

ETA: Also- I forgot to mention foreskin. I know it’s supposed to retract but I feel like the researchers should consider an uncircumcised penis for the purposes of evolutionary biology.


“The human penis as a semen displacement device” or “The evolutionary advantage of sloppy seconds”


Before I read the post I got excited because I thought that I might be able to take part in some sort of contest.


Technically, the advantage goes to one who can somehow prevent sloppy seconds from occurring.

1 Like

Did they account for the foreskin or did they just assume every single male is circumcised? Because I got some bad news otherwise, mutilating a child at birth is not evolution.

Unless they could demonstrate the foreskin somehow gets out of the way to perform this vital cleaning task.

1 Like

Sure it is. Grow up without soap and water and it might seem downright necessary. No one said evolution was moral, pretty, or has designs on contributing to the progress of human culture and civilization. All human behaviors are “natural” human behaviors by definition and given the widespread nature of this behavior in human history, it’s downright stupid to pretend it is completely without explanation or reason.


A foreskin wouldn’t change anything in this case. During sex it should work the same as a non circumcised one.

Except in the cases of diseases or infections, an uncircumcised penis keeps it’s self fairly clean on its own. Animals don’t wash themselves, nor do vaginas need to be washed out (on the contrary, douches can upset the natural balances).

12 per cent of women had had sex with multiple men in a 24 hour period, so therefore the penis serves this evolutionary function?

Someone hasn’t read their Sex at Dawn.

Good thing those weren’t common a long time ago. In all seriousness, it is specifically indicated for a number of problems.

Except humans. Who do. “Wash” is a bit of a cheat too. Plenty of mammals at least groom.

1 Like

There’s one guy in porn whose choad is like a mushroom with a glans that’s like a tennis ball cut in half. I’m not sure if it’s an evolutionary advantage, but he does seem quite popular.

I like how they consider the veejay as a passive depository of semen…as a totally inert motionless entity. Maybe they never heard of female orgasm? Look it up…it’s real. :wink:

… though unfortunately uncommon during intercourse. And it wouldn’t interfere with pump operation earlier in the process, which is what this seems to be discussing.

supposed to? it does - or perhaps more accurately, the penis lengthens during erection but additional foreskin doesn’t magically appear out of thin air in order to lengthen along with it. as such the penis extends out of the foreskin not unlike your hand extends out of the sleeve of your shirt when you put it on.

unless we’re to consider sex without an erection, the foreskin should have no impact on the outcome.

1 Like

Your father entered on your behalf

1 Like