Saturday, November 19, 2011

Sex at Dawn: Ryan and Jethá

Christopher Ryan and Cacilda Jethá's Sex at Dawn argues convincingly that monogamy isn't particularly natural for humans. It certainly is one common choice, but many modern people have a lot of trouble sticking to the program despite a lot of exhortation and systemic incentives promoting the practice. Ryan and Jethá marshall evidence from anthropology, evolutionary evidence, comparisons with other primates, and examinations of current practices. Their main argument is that a reasonable definition of "naturally monogamous" would mean that most people pair up with someone from the opposite sex, and aren't tempted to stray. There are a few species that mostly act that way, but looking at the broad range of what humans do, we're not like that. It's an interesting question as to why sociologists, and anthropologists seem to want us to believe that it is natural in the face of all the evidence.

There are several places in the book where the authors don't seem to really understand how evolution works. When talking about male parental investment, they ridicule the notion that maximum reproductive productivity is anyone's goal. It's clear from context that they're misunderstanding a discussion in which individuals are described as acting as if maximizing fecundity is the goal. But the evolutionary reasoning is just that those individuals who produce more offspring end up predominating in subsequent generations, regardless of why they acted that way. But regardless of this, they still make a strong case.

When biologists compare anatomy and mating behavior across species, human genitalia and sexual cycles don't make sense for a species in which couples stick together over the long term and don't cheat on one another. The size of male Genitalia, timing and (lack of) visibility of ovulation, breast prominence, are all unnecessary if the pair bond is unshakeable. They make sense when you assume each individual normally mates with multiple individuals of the opposite sex.

Our close relatives the chimpanzees and bonobos don't restrict themselves to single partners and we look more like humans evolved in an environment where individuals didn't restrict their attention to a single partner. In this kind of environment, evolutionary pressures push toward the large penises (by body weight), external scrotum, long duration of intercourse, and large volume of ejaculate you see in humans. If our ancestors had had reliable access to a partner, they wouldn't have needed these (evolutionarily) expensive features.

Another myth they take on is that of the demure female, uninterested in sex. It certainly occurs, but it's not predominant, either in societies (like ours) that constantly promote the idea or in societies that don't. Ryan and Jethá also make it clear that, evolutionarily speaking, homosexuality is nothing to be ashamed of. Our nearest relatives and many other species engage in the practice, though seldom exclusively. Mainstream society's insistance that each person can be categorized as either heterosexual or homosexual, is just not consistent with our behavior or the evolutionary or anthropological evidence.

Anyway, if you're not sqeamish about these topics, it's a fun, eye-opening read. Not likely to change anyone's behavior, but maybe some people will feel less constrained about their choices. It'll probably also provide grist for some arguments, but that's a fine thing, too.

Friday, November 11, 2011

Migration: James P. Hogan

James P. Hogan's Migration is a funny mix of high-tech space traveling futurism and down-home country folks. The bulk of the story takes place on Aurora, an interstellar ship on the first part of its journey, but it starts out on a mostly back-country world. We get to see some local politics and Korshak, a quick-thinking sleight-of-hand magician, who takes advantage of the local ruler's gullibility as far as he can. Korshak has a fan and friend who is on the recruiting team for Aurora, so he manages to escape his pursuers and jump into a world unlike everything he's used to. But he's an adaptable guy, so he learns to be useful in the new environment.

Korshak has to use his wits to rescue Aurora from sabotage by a subversive faction that has recruited Kek, a robot, to help them. We get the standard tour around the society as Korshak chases Kek from place to place. Some of the sub-societies are interesting, including one group trying to live at a subsistence level on this generation star ship. But Hogan makes it completely plausible.

Early on, the recruiters are interviewing a ne'er-do-well the local authorities would like to get rid of. He responds

"If it's military, or some kind of troublemaking to provide an excuse for protective intervention somewhere, the answer's no, but you don't look like a military recruiter. [That] doesn't solve anything. Just causes a lot of hate and reasons for revenge, and makes problems worse. The wrong people get rich."

"Who do you think should get rich?"

"Well, the way I see it is, nobody's born with anything. So whatever they get on top of what they produce themselves must come from other people. And the only way other people are going to give it to them is if they get something worthwhile back in return. So the ones who should end up with a lot to show are the ones who can do things better when it comes to providing what other people need."

But Hogan isn't consistently pro-commerce. The bad guys who have brainwashed Kek call themselves Dollarians and their high officials have titles like Banker. It's a fun story, but though it was nominated for the Prometheus award last year, it wasn't selected as a finalist. The side trip into Kek's attempt to be more human, (which ends up with him getting involved with a cult) is worth the trip.

Wednesday, November 09, 2011

Deutsch on the Evolution of DNA

I posted this on Google+ on Monday. I'll repost here for anyone who's not following me there. It's from David Deutsch's The Beginning of Infinity on the evolutionary origins of DNA as a universal language. I'll post a complete review when I finish the book, but these paragraphs really caught my attention.
Initially, the genetic code and the mechanism that interpreted it were both evolving along with everything else in the organisms. But there came a moment when the code stopped evolving yet the organisms continued to do so. At that moment the system was coding for nothing more complex than primitive, single celled creatures. Yet virtually all subsequent organisms on Earth, to this day, have not only been based on DNA replicators but have used exactly the same alpahabet of bases, grouped into three-base 'words', with only small variations in the meanings of those 'words'.

That means that, considered as a language for specifying organisms, the genetic code has displayed phenomenal reach. It evolved only to specify organisms with no nervous systems, no ability to move or exert forces, no internal organs and no sense organs, whose lifestyle consisted of little more than synthesizing their own structural constituents and then dividing in two. An yet the same language today specifies the hardware and software for countless multicellular behaviours that had no close analogue in those organisms, such as running and flying and breathing and mating and recognizing predators and prey. It also specifies engineering structures such as wings and teeth, and nanotechnology such as immune systems, and even a brain that is capable of explaining quasars, designing other organisms from scratch, and wondering why it exists.