Posts Tagged ‘Evolution’

Arguments Against the Paleo Diet

Monday, April 22nd, 2013

This video makes some fantastic points about the so-called “paleo diet”:

This post, which I wrote months ago, was originally much longer and incorporated many of the points Dr. Zuk makes, in particular my belief that evolution proceeds in a haphazard random way and does not necessarily lead to some supreme state.

She also puts some science behind the principle objection I have always had: that there is unlikely to be some idyllic point X at which our diet was perfectly suited to our physiology then and forever more. We have evolved with our diet. Our diet has been evolving since we were primordial slime. Claiming that our ancestors’ diet at some time X — even making the huge assumption that we know what our ancestors ate at point X — is arbitrary. Why go back to that point? Why not go back to the time when we were primordial slime eating protozoans?

Moreover, how do we know that our ancestors were eating the right foods in the first place? That’s a gigantic assumption to make based on what we know about evolution. Isn’t it possible that their paleo diet was actually bad for them? That they only ate it because they had no choice in the matter? That our technology and diet has evolved toward something better suited to us?

All that having been said, I’m not slamming the paleo diet, per se. Some people seem to have improved their health with it and I’ve found that cutting carbs benefits me. I do think the current received wisdom of cutting fat and protein and emphasizing carbs is not nearly as supported by the science as our government likes to pretend it is. But let’s not swing the pendulum too far back and pretend that the paleo diet has more science behind it. Or that any one-size-fits-all diet is appropriate. I think the point to take away is that diet is a lot more complex and a lot less well understood than we would like.

Texas Linkorama

Wednesday, December 12th, 2012
  • The idea of building gondolas in Austin strikes me as a really dumb. Gondols are slow and would take up lots of space for the number of passengers they transport. Texans aren’t big on mass transit to begin with (the light rail system is likely to be a flop). And what do you need a gondola for in a city that is really flat? This crosses me as a solution in search of a problem. And if it doesn’t have high ridership, it’s bad for the environment. And expensive.
  • Down with homework!
  • I always suspected that the high I got off parenting was an evolutionary thing. I find these things intriguing and fascinating. Much of what we feel in life: compassion, empathy, love, tenderness is the result of millions of years of evolution making us into creatures that look for the species rather than ourselves.
  • A really good post on the Jefferson slave thing. Also, highly recommended on the subject: Ta-Nehisi Coates. Actually, TNC is just recommended, full stop.
  • One day, parenting authorities will get it through thick skulls like that fun physical activities are good for children even when they involve a low amount of risk.
  • Ah, peak oil. These days, the biggest energy concern is that we won’t run out of fossil fuels and that global warming will be worse than feared.
  • A fascinating story from NPR about how our image of Jesus has changed with social norms.
  • While it strikes me that global helium supplies are a legitimate concern, the idea that our technical needs in 50 years will be the same as they are now crosses me as silly. Think about the chemicals that were important 50 years ago. Are we in the grips of a global lead shortage?
  • Breasts

    Sunday, July 15th, 2012

    For some reason, breasts have been in the news lately. Not one but two scholarly works are out, one of which is nicely skeptical about all the received wisdom about their form, function etc.

    Apart from my Y-chromosome issues, I find this subject interesting because of the discussions about precisely why men are attracted to women with large breasts. It’s simply amazing to read all the debates in evolutionary psychology which pass themselves off as science but are often little more than speculation (check out this baby for an example). I’ve heard all the “theories”, few of which are actually falsifiable. And all of them sound like rubbish to me.

  • Men are attracted to women’s breasts because they want their young to be well-fed. This is likely to be garbage as there is little, if any, correlation between breast size and the ability to nurse.
  • Men are attracted to women’s breasts because it indicates higher body fat and better nursing of children. See my response to the first explanation. I’d also note that breast size and body fat are not perfectly correlated. The most common body types are the “banana” and “pear” shapes.
  • Men are attracted to women’s breasts because they resemble women’s buttocks. This is a popular explanation but it also sounds like rubbish. First of all, it only deflects the question: “OK, wise guy: why are men attracted to women’s butts?” Second, this was clearly derived by people who have no idea what breasts looks like in the wild. Corsets and bras have only existed for the last half a millenium.
  • Men are attracted to women’s breasts because they swell during ovulation, signaling fertility. This swelling is subtle to anyone who is not experiencing it; far more subtle than the breast fetish tends to be. Moreover, many women do not experience breast swell during ovulation. And breast swell is far greater during pregnancy, when a woman, by definition, is not fertile. For our primate ancestors, it’s likely the very presence of breasts indicated a female was pregnant or nursing.
  • Men are attracted to women’s breasts because of socialization. Now this one really annoys me. Socialization doesn’t just happen on its own. Breast fetishism had to come from somewhere. It’s not like someone woke up one day and decided to tell all the men to eroticize boobs for some sort of oppressive reason. Breast attraction must have a long and deep history in our species to have affected our very evolution (humans females are the only mammals to have large breasts when they aren’t lactating).
  • To be honest, this debate tends to fill me with anger. All of these theories are presented with an incredible certainty, as though something had been proven. But none are supported by scientific evidence. They are mere conjecture and bad conjecture at that. Among other things, none allow for the fact that some men are not attracted to busty women. In fact, some men have a particular preference for women with small chests. Many cultures have a far less intense breast fetish than our own. And some men — like me — are attracted to a variety of physical types. So these explanation that big boobs appeal to something deep in our psyches or our genes leave me a little cold.

    These theories also ignore something very important: there may not be a reason. One of the things we’ve learned from evolutionary science is that we are not perfect creatures. We have many flaws which have been genetically selected over the generations. The reason we have these flaws is that they came along with something so useful that, on balance, we were better off. So intelligence may have come with bad eyesight. We are, and always have been, patchwork creatures. And the idea that evolution is a uniform process producing predictable results and that every aspect of our existence has some survival benefit is inconsistent with the known facts.

    In sum, men may be attracted to big boobs because of some random bit of programming that came along for the ride with something else. Or it may be an unusual manifestation of something that is useful. Looking for a definitive explanation is, in my view, dangerous because it implies that all our traits, all our behavior, have to have an explanation. They don’t.

    That having been said, I recently encountered a theory that makes some sense to me.

    I recently heard an interview with one of the authors of A Billion Wicked Thoughts, which applied the first objective analysis not to what people claim to consume on the internet, but to what they actually do. For example, far more men are attracted to women who are overweight than women who are anorexic. While the authors go too far in some of their conclusions, the interview did have one idea that resonated. The author was talking about why men fetishize things like dainty feet. He said, quite simply, that these are signs of femininity. They are things male brains — because of evolution, socialization or hormones — recognize as “this is a female; I can mate with her.” It is sexual signaling, no different from the bright feathers on a bird or the pheromones of an insect.

    This is probably the most sensible explanation for the breast fetish I’ve heard. It’s straight-forward and explains much of what the other theories don’t. Under this paradigm, men are attracted to anything their brains have decided is feminine. And breasts are just one of the easiest things to fetishize because they are such an obvious secondary sex characteristic; something women have that men don’t. A man can see a busty women from far away and recognize that it’s a woman. There doesn’t have to be a rationality behind it. He doesn’t have to be thinking about her ability to lactate or anything. It’s just something that his brain has latched on to.

    The real beauty of this theory, however, is that it does not have to be true of all men. If a man associates femininity with being small and petite, or having long hair and soft skin, or having a high-pitched voice — that’s what he finds attractive. He can be completely indifferent to mammary glands simply because his brain does not process that as a particularly feminine trait. Breast fetishism would simply be part of the larger paradigm that encloses all fetishes. Call it the General Theory of Ogling.

    (I should note that women are not immune from this sexual signaling, hence the preferences for broad shoulders, deep voices, etc. However, women tend to be less visual and their sexuality is more oriented around mate selection than mate identification. So if wealth or self-confidence or humor or whatever is what they regard as a signal of masculinity, that’s what they find attractive. This may also explain why women are often attracted to men who are obnoxious or even violent, since these can be masculine characteristics.

    I’ve often felt that natural selection, at least in humans, is something that women play a much larger role in than men. Men try to have sex with everything, superior or inferior. Women are the ones who are selective.)

    Of course, I would be remiss if not noting that this conjecture makes me feel better about myself. While I have always been very physically attracted to women, I don’t really have a “type”. My wife is blonde and curvy. My previous girlfriend is tall, brunette and slender. Before that was short and petite. Before that was short and absurdly busty (and possible artificial). And so on. I’ve been attracted to blondes, brunette and redheads; to tall and short; to slender and curvy. But I would define all of them as physically attractive in some way. In fact, I would say that I find most women attractive in some way. But if you narrowed it down just to the women to whom I have felt a strong physical attraction, you would still find a wide physical variety.

    That I am physically attracted to women of a wide variety of appearances used to bother me. But now it just means that my brain, for some reason, defines a broad spectrum of physical characteristics as female. Maybe it’s some subconscious “with your luck, you can’t be too picky” thought stream. But I suspect it’s just the way my brain works. I have broad interests in everything, hence the blog, hence the career in a massively interdisciplinary profession, hence the liberal arts education, hence the huge library. My interests tend to wander. And so does my eye.

    We are animals. And we are fools when we forget this. We are double fools when we have degrees in scientific disciplines and deliberately forget this. Our rational thinking selves are just the placid surface of a broiling animalistic mix of desires, passions and fears. We can’t pretend that every aspect of our lives — and especially the most basic aspect of our lives: our need to reproduce — are the product of reason and rationality. Nietzsche said that the degree and kind of a man’s sexuality reach up into the ultimate pinnacle of his spirit. Our spirits are animals. And our attractions are no different than an animal’s attraction to a set of big antlers or a particularly shimmery coating of scales.

    Saturday Linkorama

    Saturday, September 24th, 2011
  • Holy crap. Freakonomics backs me up on how spineless and useless NFL pre-season picks are. I really should be an economist.
  • Cracked takes on Doctor Who. It’s so weird to see this show become so popular. When I was a kid, Whovians were looked down on by Trekkies.
  • What 40 years of war has done to Kabul.
  • I’m not sure about this story. The Drug Warriors have a noted tendency to overstate their case, as does the CDC.
  • I can’t tell is this vampire kit is a real thing from the 19th century or somebody’s art project.
  • Another missing link has been found. But remember, finding a transitional fossil just means you need to find two more.
  • If it weren’t for his Fair Tax position, I’d really like Gary Johnson.