Evolution 101

Sunday, October 29, 2006

The Female Orgasm

Well, the first attempt at the Evolution 101 live broadcast was kind of a bust. I only had one person tune in to ask me a question, Scott Burger, who asked about the potential for human speciation in the context of space exploration. I don’t know if I was sufficiently able to answer his question because his internet connection kept dying on him, but the gist of my response was this: given humanity’s capability for technological adaptation, our genetic adaptation is probably going to be minimal, even once we begin to explore different planets. I would imagine that we would use our capacity for technology to replicated as best as possible Earth’s environment wherever we go, so the necessity for adaptation will probably be pretty low. There’s a more pressing distinction, however- the founder effect. If our understanding of the laws of physics don’t change dramatically before then, we’ll be faced with the very real prospect of population separation once we do begin to colonize other planets. It just isn’t physically feasible, unless something like Star Trek’s warp drive or Star Wars’ hyperdrive is invented, that allows for the travel form one planet to another in a reasonable timeframe. Otherwise, once you decide to visit a new planet, that’s it- you live there and die there, and likely you children and children’s children too. The only way to avoid that multi-generational aspect of space travel is suspended animation, like is used in 2001: A Space Odyssey. But even then, the sheer distances required to travel mean that a crew of any significant size will maintain a particular genetic sample which is for all intents distinct from the population back home on Earth. Because remember, evolution really works on populations, so once you’ve removed one population from another, so that the exchange of genetic information is stopped, there is the potential for speciation, especially if there are significant forces affecting adaptation from the environment. But this would take a long time, much longer than the 10 generations that Scott was guessing it would take.

So, anyway, that was it for the live show. Not really enough to save and podcast on it’s own, so I just reiterated my answer here. But I am going to try again next Saturday at 4:00 PM CST, so send me an email if you’re planning on showing up, otherwise I won’t waste my time.

As it happens, there’s a few good questions that I received this week that I really wanted to address here, so I’m just going to go ahead with the regular format. Also, since it’s so close to Halloween, I thought I might talk about something truly frightening- the female sexual response and evolution! But first, the questions.

Garrett and Leslie both wrote to ask about the relationship between evolution and morality. I’ve just finished reading “The God Delusion” by Richard Dawkins, and he devotes an entire chapter in that book on the subject of morality, so I would recommend that highly to anyone who finds this topic as fascinating as I do. Garrett asked if a sense of inherent morality existed in humans, and why did it arise?

I think that an inherent sense of morality does, in fact, exist within humans, and to lesser extents within other animals as well. Experiments have been performed in primates, for example, that establish a clear sense of “fairness”- if two chimpanzees are given treats separately, and one is given a banana but the other is given a carrot, but they can’t see each other, both chimps are quite content with their respective prizes. But if both chimps are in full view of the other, and the same treats are given, the chimp which is given a carrot reacts negatively to the observed inequality (obviously, a carrot is an inferior treat to a banana). In fact, the chimp who receives the carrot will, if he knows that his comrade has been given something better, refuse to eat the carrot until he is given a banana as well. So I think that this points to a genuine sense of fairness, which isn’t unremarkable if you think about it, because chimpanzees are very social creatures, and some kind of ingrained rule system would be adapatively useful to preserve the social order.

You can make the same kind of argument about humans, but since we can verbally communicate, there is the ability to discover even more subtleties about our moral convictions. And given the scientific method, you can even measure them. In his book, Dawkins relates the results of several psychological studies on morality, in which specific questions are asked in the context of hypothetical situations. For example, let’s say a train is speeding down a track, and there happen to be five people standing on the track ahead, about to be hit by the train, and with no way to save themselves. Then let’s say that you are standing at the track switcher, and can move the train from its present track to a side-track, avoiding the five people ahead. But there also happens to be a man standing on the side track, who will be assuredly killed if the tracks are switched. What is the moral course of action?

And the vast majority of people will say that it is moral to switch the tracks, because it is better to save the five people even if the one man is accidentally killed. Simple enough, but there are many different permutations of this example, each one affecting the morality of a particular choice. I won’t get into those details here, but I will say that the morality of these situations seems to be, upon asking large groups of people, under general agreement. If you want more information, then check out Dawkins’ book. But my point is not that what is right is decided based on what the majority of people think. But if there were some inherent moral sense, then we should expect to see most people coming to the same conclusions given any moral situation. And in fact the same moral responses are found whether you’re asking college psychology students, or isolated tribesmen in the Amazon- what is moral seems to be pretty well-known, even if it’s difficult for people to articulate why. This is similar to the sense of lust- an equally universal, evolutionarily-selected sense. You may not be able to explain why exactly you find a man or a woman so appealing, but you know that you do, and evolution explains it perfectly.

Ravi asked about the genetic basis for the variety of human faces. Yes, our facial features are genetically based, as are pretty much all of our physical features, like height, hair color, eye color, etc. The fact that our facial features are remarkably individualized, with similar-looking people extremely rare, (although occasionally some Dopplegangers do meet, it’s primarily a dramatic device used in movies) is likely the result of our being such visually-oriented creatures, and also highly social. But this may be just a psychological illusion- there is the clichéd phrase, “you all look alike to me” which is used commonly when a person of one race is referring to another race, whether it be a black person talking about white people, a white person talking about Asian people, or an Asian person talking about black people. Certainly other species exist, such as chimpanzees, which are highly social, but whether a chimpanzee’s face is as distinctive to a chimpanzee as a human’s face is distinctive to a human, I don’t know. There are other species, such as whales, which use sound as their primary means of identification, and we do know that different groups of whales have different “languages” when they communicate- I wouldn’t be at all surprised if a whale’s “voice” is distinctive at the individual basis as well.

Julian asked about the video game Metal Gear Solid. Yes, I have played (and beaten!) that game, and am familiar with the premise of the genetic development of “Super Soldiers.” This is a new play on the significantly older theme of eugenics, which of course we can thank the Nazis for giving such a bad reputation to. There have been other popular media incarnations that used the idea of genetically breeding super soldiers, like the X-Files and Dark Angel, to name a couple recent television shows. First of all, there’s no compelling scientific reason why a concerted effort couldn’t be put into place to breed soldier-humans. It would be no different from breeding dogs for characteristics that make them good fighters. But doing it the old-fashioned way would take hundreds, if not thousands of years, assuming a minimum generation time of twenty years. We could maybe speed things up if we knew precisely which genes conferred the desired traits, but we’re not quite there yet. It’s going to be quite a long time before we can do justice to the human genome, and as far as I know, the alleviation of human disease is much more pressing than the generation of any super soldier. One thing about Dark Angel I found amusing is the idea of transferring genes from animals into humans, based on the idea that cat DNA could make someone be able to jump as high as a cat. Sorry- the reason a cat can do what it can physically is because of the entire development of its body, not just a few choice genes. To be able to get a human to function like a cat in terms of agility, you would have to change its anatomy to a sufficient degree that it probably wouldn’t look like a human anymore, much less Jessica Alba.

And while we’re on the subject of genetics, evolution, and popular television, I want to just point out really quickly that the new show “Heroes,” while it may be a compelling drama, is about a wacky as you can possibly get in terms of understanding evolution. There’s the book that is central to the plot thus far which is called, “Activating Evolution.” Sorry- no such thing. It makes about as much sense as “Activating Gravity-“ which, given the ability of one of the characters to fly, would have a lot more to do with the plot than evolution. Simply put, this is not science fiction, this is pure fantasy- closer to the X-Men than to anything that has to do with science. If you want to see a movie that really deals with the human issues involved in the control of evolution, go see Gattaca.

And finally, something really frightening- the female orgasm. What does this have to do with Halloween? Nothing, really. But I am a little afraid of what my female listeners will say after I talk about it. I recently listened to a lecture by Dr. Elisabeth Lloyd, author of “The Case of the Female Orgasm.” She talks about the evolutionary explanation for the female orgasm, and why she thinks that male-influenced science has distorted the way that the female orgasm has been regarded by science. There is, as should be obvious, a great deal of political baggage associated with this topic. Prior to the sexual revolution, the female sexual response was barely regarded by science- any kind of sexual anomaly was regarded as simply female hysteria. Strangely enough, the first dildo (in modern times) was invented as, surprise, surprise, a remedy for this hysteria, because it seemed that troubled women became much more relaxed when, well, diddled (assuming that word has scientific merit). At that point, the only orgasm that mattered was the male orgasm, because that is what made babies, and anything else experienced by women was just unnecessary. But during the sexual revolution, the rise of feminism prompted women to claim their sexuality for themselves, at which point the female orgasm was regarded as just as important as that of the male. At this point science followed politics, as many scientists, such as Desmond Morris, began to submit evolutionary rationales for the existence of the female orgasm. But for there to be some evolutionary explanation, there had to be some kind of adaptive function that the female orgasm played that made it essential to reproduction. And therefore it was proposed that female orgasm existed to cement the pair-bond that was formed when a couple had intercourse. That in order to better care for children, a couple needed to have a strong bond, and mutual orgasms cemented this relationship. This was tempting, but unfortunately was not born out by the numbers. Most women do not have orgasms by intercourse alone, although they can induce orgasms quite easily by masturbation. So this seems to contradict the idea that female orgasms play a huge role in the psychological benefits of intercourse. Then there was the “sperm upsuck” theory, in which is was postulated that the female orgasm caused more sperm to be retained in the vagina after intercourse, and so promoted reproduction in that way. This theory actually gained some wide acclaim, but Dr. Lloyd points out that the actual experiments behind this theory were performed so unscientifically as to be completely ruled out. But the psychological damage had already been done- giving female orgasms a strong functional role to play meant that they were important, and thus not only women were concerned about them, but men too.

Dr. Lloyd suggests that female orgasms aren’t functionally important. There just isn’t any evidence to suggest that they reinforce the pair-bond, nor that they enhance sperm retention. Her conclusion is that female orgasms are just like male nipples- a shared, but inessential characteristic in one sex because in the other, they do serve a very obvious adaptive purpose. As I’ve talked before about male nipples, they occur because the development of humans follows a common path in utero before certain hormones cause males to diverge from the standard female development path. Likewise, our genitalia are based on a common form which in males becomes the penis and testicles, but in the female becomes the clitoris and ovaries. It is essential for the male orgasm to take place- otherwise, there would be no fertilization. And since the female genitals are related developmentally to the male gentials, the potential for orgasm also exists (and is tied to the clitoris, not the vagina), but exists, as Dr. Lloyd concludes, as a “happy bonus,” but not as an essential function.

The criticism that Dr. Lloyd gets is primarily from women who feel entitled to their orgasms, and feel that the dismissal of any functional purpose makes their orgasms less important, even to suggest that they shouldn’t be having them. But this is not the case- she does call it a “happy bonus,” after all. The fact that female orgasms exist because of male orgasms should be a chance for reconciliation between the sexes. After all, women wouldn’t have orgasms if it weren’t for the need of men to have them too. If you want to learn more about this, check out Dr. Lloyd’s book, “The Case of the Female Orgasm.”