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Woman Created Intelligent Man

10:30 / 25.05.02

I just read an article in New Scientist about how, because of having XY rather than XX chromosomes, men are more susceptible to natural selection involving intelligence (and some other charcteristics).

On top of this, the idea is that one of the reasons we had an evolutionary burst in brain power is due to women choosing intelligent mates, rather than brawny types. This intelligence then dominated the male gene pool and women got the benefits too. I'm not sure I really like this idea, but it is pretty striking.

Report on the article here

11:44 / 25.05.02

"Me no understand! Hulk mad! Hulk SMASH!!!"

Well, I guess that explains why I'm still single. *rimshot!*

On top of this, the idea is that one of the reasons we had an evolutionary burst in brain power is due to women choosing intelligent mates, rather than brawny types.

It would stand to reason. After all (and correct me if I'm wrong) but humans are the only species on the planet that can't survive without the use of tools. Especially in this day & age. Granted, they just came out with that story about the chimps using rocks like hammers. But primates don't rely on tools for survival in the same way we do (note the chip on the human's shoulder). Ergo, the discriminating female might go for the Bruce Banner rather than the Hulk-type as the former would have a better chance to bring home the bacon.

17:04 / 25.05.02

A discussion on Radio 4 a few weeks back had a member of the panel suggest that survival of the fittest doesn't apply to a large number of species as those most likely to survive are the ones who can think themselves out of danger rather than relying on force.

Less searchable M0rd4nt

18:39 / 25.05.02

I think possibly your interpretation of the "fittest" is rather narrow. I know that when people employ the phrase "survival of the fittest" as a metaphor or a colloquialism they generally mean something along the lines of "If I rip off your arms and legs it's your fault for not rtipping mine off first", but that's not quite what Charles Darwin had in mind.

"Fittest" in the classical Darwinian sense means "best able to adapt and survive in a particular environment or set of circumstances." Nowadays, the phrase is extended to mean the ability to pass on one's genes to one's offspring.

Whilst physical force might be a factor in this "fitness", it's easy to see how intelligence might also make a species more fit in the Darwinian sense.

22:24 / 25.05.02

Enkidu and Shamhat.

13:57 / 26.05.02

Whoops. I missed a point out there. I guess what you're saying is that it's the individuals with a decent 50% mental/50% physical abilty balance who are most likely to win out over time. Whoever it was arguing their case (and I've tried, but can't remember) was going as far as saying that, in the case of the human species at least, it's likely that those who have survived are actually physically weak to the point where their physical abilities are negligible, the resulting disproportionate reliance on mental skills being the factor that's determined their survival.

Less searchable M0rd4nt

16:38 / 26.05.02

Well, no. That's not quite what I was saying. What I meant was that from a Darwinian point of view, intelligence is just another trait- like a bird's flight trait, or a fish's gills, or a bat's sonar. It's something that's arisen because at some point in evolutionary history, being smart gave some of our ancestors an edge in the genetic game.

It's not possible to predict which characteristics are going to give a species an evolutionary advantage because we can't know what circumstances might arise, or what traits might offer the best ways to cope with those circumstances.

22:42 / 26.05.02

Does that still count when your species reaches the point where it's capable of manufacturing the circumstances of the future?

I'm thinking of that question in two scenarios. Firstly, there's an argument that humankind may have reached - or be nearing - its evolutionary peak as it's actively remodelling the world to be the best fit for the body's current form and manufacturing artificial aids to any hurdles encountered. Secondly, what if the drastic way in which our world has been transformed to meet our needs triggers its own evolution? Couldn't we predict what our future selves may look like by ensuring the preceding generations are borne into a specific type of environment?

That's all ethically extremely shit, of course.

17:24 / 27.05.02

I don't think there is such a thing as an 'evolutionary peak'. We may be remodelling the world but that doesn't mean we've somehow 'stopped' evolution. Something I think would be impossible short of stopping time (even more unlikely). As for controlling evolution (/me suppresses laughter); no chance. Sure we'll be able to genetically engineer people reliably in the not so distant future but even then we'll have little idea what the effects will be a few generations down the line. Let alone a few million years. You may as well say you want to predict the future...

15:44 / 28.05.02

There’s a book on sex and evolution called “The Red Queen” that presents a persuasive argument that human intelligence did not arise as a survival-based characteristic: Our complicated brains gave us very little survival advantage on the savannah before the taming of fire, the spread of complex tools, the creation of written language and the domestication of plants and animals. According to this theory, human intelligence was a sexually desireable characteristic that conferred a reproductive advantage, much like the male peacock’s tail. Have a look; it’s an intriguing book for laypeople.

11:30 / 29.05.02

I'm about to go and read the article, but I just thought I should mention from the off that it seems to me to be a rather weirdly sexist and simplistic explanation - why wouldn't men choose intelligent women? If you were going to be purely functional about it (and perhaps equally sexist), it would seem that you'd expect some degree of specialisation between the sexes. If the men were brawny and more suited to the types of behaviour associated with brawn (lifting, carrying, fighting, killing, hunting) and women didn't do this stuff, you might expect the women to develop alternatively useful strategies... Just seems to me to be an imposition into the past of the assumption that men won't be attracted to 'more intelligent' women...

11:46 / 29.05.02

Sleeperservice: I don't think there are such things as evolutionary peaks - life is too complex. But there are instances of evolutionary stability where evolution works in the direction of staying still. I'm, thinking of crocodiles, or is it alligators? The ones that have been around, essentially unchanged, since the dinosaurs.

Chuckling Duck: The thrust of the article I read was that intelligence started off as conferring only a minimal survival advantage. It was selected via female sexual choice and then snowballed because it does provide enormous advantages. This is in contrast to the peacocks tail, which is also thought to be the result of sexual selection. The difference being that for peacocks, the tail is an actual disadvantage and so there is a tension between sexual selection and "fitness" at a purely survival level.

For intelligence, there is no such tension and you get some positive feedback going.

To answer Tom's point. While the premise does seem sexist, it relies on genetic differences between men and women. Namely, the XX chromosomes of males mean they are more susceptible to certain types of mutation - this is evidenced by a variety of diseases that affect males only. The key piece of new research suggests that intelligence (the broad amalgam of qualities that comprise it) is liable to greater mutation within males, for the above reason. So if men selected intelligent female mates, this would have a far lesser effect than the converse.

To sum up, the scientists aren't being sexist. God is.

11:48 / 29.05.02

BTW - I read this in (a hard copy) of New Scientist and the article I linked to is much more sparse in terms of detail. If anyone can find a better reference, that would be much appreciated.

18:43 / 29.05.02

Tom Coates: “I'm about to go and read the article, but I just thought I should mention from the off that it seems to me to be a rather weirdly sexist and simplistic explanation - why wouldn't men choose intelligent women?“

Good question! It’s best answered with the answer to a different question: Why DO men choose intelligent women?

In other animal species, females are almost always the ones that choose their mate if there is a choice to be made. This is because males can increase the number of their offspring though polygamy, and therefore have no reason not to mate with any available female, but females cannot increase the number of their offspring through polyandry, and so have an interest in shopping for the best genes available. That explains why male animals are usually the ones with sexually selected display traits, like peacocks and bullfrogs and so on. (In lekking species, anyway. Harem species like horses, gorillas, deer and so on are also sexually dimorphic, but the male traits are for battle, not display.)

However, in species where the young require a great deal of care and attention, such as the completely helpless human infant, the male may have to invest a great deal of time and energy into providing for his offspring if they are to have any chance to survive. These species tend towards monogamy, and tend to be less sexually dimorphic. However, males and/or females of these species sometimes have sexual display traits or other adaptations that are useful in maintaining the pair bond. Intelligence may have been one such adaptation.

I’m summarizing here, and poorly. The Red Queen not only presents the field evidence, but also gives the general background needed to understand it. I really recommend the book. There’s a lot of other good stuff about sex and evolution in it, including why sex is advantageous for some species but not for others, and why there are two sexes rather than three or four or five. (It’s not, as I first guessed, that we would never leave the house.)

15:07 / 30.05.02

I think it is not that men or women are doing the choosing that is important so much as the specific case of women choosing men having a greater evolutional effect than men choosing women. Choosing is going on in both directions. However, one is shown to have a greater effect over the other, so it is being considered more relevant to evolution. Tis not sexism, tis statistics.