next »

[fiona]

Stuff we need to know and comment on.

http://chronicle.com/article/How-Our-Brains-Got-BigOur/128878/

The Fiona

[monita]

Do I really want to be the first to comment on penises?

Humans are also the only primate to lack a baculum (a penis bone), although they are admittedly pretty dinky in the other African apes.  People are often quick to link these sorts of changes to the evolution of monogamy, but since true pair bonding seems to be quite rare among humans worldwide I'm not convinced.  I've read that the lack of the baculum, anyway, provides a form of sexual competition, since it requires the male to maintain an erection through hydraulics, so to speak, which would be very difficult if you have vascular or other health problems.

It's early and I'm too lazy to find citations, but I'll have a look if anyone is interested.  All I know for sure is that I am VERY glad penis spines are a think of the (evolutionary) past.

[anthroid]

I was just talking about this in class today, as a matter of fact.  Here's an interesting article on both penis size and testes size.  Gorillas have the smallest penis and the smallest testes among the apes, humans have the largest penis and middling-sized testes, and chimps have a middling-sized penis and huge testes.  The hypotheses seem to be that, when there is very little chance of sperm competition, the penis and the testes can be small, and when there is a good chance of significant sperm competition, the testes have to be big.  Humans, as always, confound everything--our (comparatively speaking) big penises could have something to do with female preferences and the middling-sized testes could be related to the human tendency to avoid lifelong sexual exclusivity.  And the lack of a a baculum in humans gives a whole new meaner to the word "boner."

[navydad]

I knew John Boehner was spineless, but this sheds a whole new light..... Never mind, that's gross.

[sciencephd]

Yes, the headline gives an apt summary of the level of science coverage and reporting generally in the Chronicle.

[csguy]

When I saw the headline I thought it was about people and using penis as a polite substitute for prick. I was just not sure what people it might be referring to.

Pick your candidates.

[fiona]

Bumping this up cuz I'm tired of seeing the same thing at the top of the fora.

Otherwise, I gots nuthin to say on this subject.

The Fiona

[bcohlan1]

Wait, we're not supposed to have an actual bone in our penises? 
*Calls the doctor.*

[ardea]

I always learn something new here, but often it is not usually something I want to learn. I googled baculum to see what exactly it was and it quickly led me to depths of the interwebs best left undisturbed.
 

[oldfullprof]

My latest hoot is the anti-Viagra movement among a very small group of feminists, including at least one sociologist.  They claim that "Viagra men" force sex on older women who don't want it, that it acts like an aphrodesiac, etc. 

I'm going to give an opposing paper on how this is an example of an attempt to start a mini-moral panic.

Die Fahne hoch (excuse the origin of this reference.)

[jackofallchem]

When I saw the headline I thought it was about people and using penis as a polite substitute for prick. I was just not sure what people it might be referring to.

Pick your candidates.

Yes, I was expecting another article about a faculty vs administration conflict.

[al_wallace]

Not just the size, but the degree of ornamentation is also related to the mating system of the primate. The studs and spines on primate penises are generally associated with those that live in more promiscuous mating systems. Simple and plain penises are associated with (sort of) monogamous primates or at least that's what Dixson's data suggests (1987). I think Dixson (that really is the author's name) suggested that these structures had a stimulatory effect on the female reproductive tract. Subsequent work by William Eberhard makes a similar cryptic female mate choice inferences. Another hypothesis (written on the back of my napkin) is from the perspective of male-male competition. I think these structures irritate the female reproductive tract, cause swelling, and induce an immune response in the females such that any male that mates with a female too soon afterward would be met with a mounted attack on the subsequent suitor's sperm. In other words, it is a physiological equivalent of a chastity belt or copulatory plug. I could also imagine that taking the equivalent of a brillo pad to a vagina just might make it swell shut. The benefits in the context of sperm competition are clear. The benefits to the female in this case? None...which sets the stage for selection pressure on females to limit multiple matings.

Researchers claim that there is far too little work done in comparative primate sex research. I can't imagine why. I mean, who doesn't want to chase bushbabies through trees in the middle of the night while waiting to catch a female having rough sex and then swinging over quickly to inspect her vagina? The descriptive science involved here seems pretty straight-forward to me. The logistical difficulties can't be any worse than trying to find out if gorillas have orgasms or not.

This article reminds me of a study that showed an inverse relationship between the size of a male bat's brain and his testes size. You can have one or the other, but not both. Insert your own joke here.

[fishprof]

If you want Baroque penes, the Odonata (dragonflies and damselflies) cannot be beat.  All sorts of convolutions, spines, brushes and hooks, apparently for removing all vestiges of a previous mate's semen from the reproductive tract of the female, which is similarly ornate.

This also leads to the varieties of sperm: Fast swimmers for fertilization, hunter-killers to track rival sperm down and destroy them.....it's almost worthy of a video game....

[missemily]

Bumping this up cuz I'm tired of seeing the same thing at the top of the fora.

Otherwise, I gots nuthin to say on this subject.

The Fiona

You mean you're trying to get it up?