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Evolution's Path May Lead To Shorter, Heavier Women

Hugh Pickens writes "Yale University researchers believe that if evolutionary pressures of sexual selection and reproductive fitness continue for another 10 generations, the trends detected in their study may mean that the average woman in 2409 AD will be 2 cm shorter, 1 kg heavier, will bear her first child five months earlier, and enter menopause 10 months later. 'There is this idea that because medicine has been so good at reducing mortality rates, that means that natural selection is no longer operating in humans,' says Stephen Stearns of Yale University. 'That's just plain false.' Stearns and his team studied the medical histories of 14,000 residents of the Massachusetts town of Framingham, using medical data from a study going back to 1948 spanning three generations, and found that shorter, heavier women had more children than lighter, taller ones. Women with lower blood pressure and cholesterol were also more likely to have large families as were women who gave birth early or had a late menopause. More importantly, these traits are then passed on to their daughters, who also, on average, had more children. The study has not determined why these factors are linked to reproductive success, but it is likely that they indicate genetic, rather than environmental, effects. 'The evolution that's going on in the Framingham women is like average rates of evolution measured in other plants and animals,' says Stearns. 'These results place humans in the medium-to-slow end of the range of rates observed for other living things.'"

27 of 411 comments (clear)

  1. Reproductive "success" is not genetic. by acon1modm · · Score: 3, Insightful

    I think evolutionary change is being stifled by both medicine and civilization. Reproductive "success" is not genetic anymore, its based on social factors. The goal of most humans is no longer to spawn the most progeny.

    I come from a small backwoods town and women in these areas (e.g. low income, low education) have more children, and have them at a younger age. ( This is a generalization, no anecdotes please. And no I don't feel like looking up stats, maybe someone else can post some).

    Also, regardless of the details, I hope TFA is wrong. Have you seen dwarven females?

    1. Re:Reproductive "success" is not genetic. by NoOneInParticular · · Score: 2, Insightful
      I think the article argues that your 'impression' that evolutionary change is being stifled by both medicine and civilization is plain false. Also, it might be that the goal of most humans is to lead an fruitful and interesting lifes, but also that's irrelevant. Bottom line remains that whoever spawns most progeny will spread their genes. It is that simple.

      You might want to think things through a bit more, as your preliminary paragraph displays a very incorrect view of how selection operates. Whoever makes most kids, takes over the population, genetically. Also, if dwarven females are that ugly, there you have an immediate selection pressure against them taking over.

  2. Fat Americans Breed Fat Americans! Film at 11 by tomhudson · · Score: 1, Insightful

    Change the diet, and you'll see the "trend" reverse.

    1. Re:Fat Americans Breed Fat Americans! Film at 11 by petes_PoV · · Score: 2, Insightful

      skinny women are less fit hosts for a fetus than heavier women

      Maybe they've got cause and effect the wrong way round. Maybe after the first baby, the women in this study put on weight. Women who didn't have children didn't gain weight so skewed the samples and results?

      --
      politicians are like babies' nappies: they should both be changed regularly and for the same reasons
    2. Re:Fat Americans Breed Fat Americans! Film at 11 by Anonymous Coward · · Score: 1, Insightful

      The only intelligent reply herein. From a female, this is not new information. Historically, as you can see depicted in paintings such as Rubens, women tended to be shorter and heavier. From my history recollection, it was not until the 1920's in America that "thinner" women became something that was even desired. In many cultures, a heavier trunk and chest is indicative of better reproduction health, and as such, more desireable to the male counterparts. (The fetus survives off of fat stores in the hips and abdomen for I believe the first 2 trimesters.) I have known very many thin women who were majorly reproductively challenged even at younger ages.

      The truth here is that there is a critical limit of "fat" for good reproductive health. You need enough fat to get pregnant and maintain a pregnancy, but too much fat can actually prevent ovulation, and as such, pregnancy.

      It is not evolution that is causing girls to mature at a younger age, it is diet. You have to get a certain amount of fat (what we used to call "baby fat") to start menstruation. Many girls are now getting that because of diet at an earier age than our mothers. Also, the trend of an earlier menarche equaling a later menopause is not new knowledge. I learned that 30 years ago in SexEd.

      And trust me, there may be a lot of women who like those toothpicks on their arms, but those same men are going behind the scenes looking for some women with a little bit more junk in their trunks.

  3. Re:Idocracy by skine · · Score: 1, Insightful

    [T]here's nothing wrong with observing trends like "less intelligent people have tons of babies."

    Actually, there is something wrong with observing false trends.

  4. Preferences by Smivs · · Score: 3, Insightful

    It could just be that the Menfolk of Framingham fancy short fat women. Perhaps they're all short and fat as well.

  5. Re:Population trends and the direction of evolutio by TheLink · · Score: 3, Insightful

    1) The children will take some characteristics from their dads as well.
    2) A few generations of people doing what you say and you might have a breed of humans more likely to rape.

    --
  6. Re:Idocracy by 4D6963 · · Score: 5, Insightful

    Give that idiocracy shit a rest. It's not genetically dumber people who make more children, it's people lower on the social scale. As in, people in ghettos and immigrants. Poor education and poor nutrition (both which cause lower IQs) aren't genetically hereditary.

    So-called smart people always confuse uneducated people with less intelligent people. Maybe they're not that smart after all.

    --
    You just got troll'd!
  7. Re:Alrighty Then by Anonymous Coward · · Score: 1, Insightful

    Creationists believe in Natural Selection ... snip ... but the DNA is more corrupt overall.

    So... Creationists don't believe in Natural Selection, and clearly don't even understand what Natural Selection is.

    There is no "perfect" DNA defining the "ideal" genotype, against which a particular creature's DNA can be said to be "corrupt". Corrupt is a weird choice of word anyway because it implies a moral comparison. If a mutation results in traits that increase the odds of reproductive success, it is more likely to be included in the DNA of future generations than the "un-mutated" version or versions with deleterious mutations.

    It's wonderful sophistry though. Any time somebody shows them an example of genetic change generating beneficial adaption, it can be dismissed as "sure, the bacteria now has the ability to survive a previously unknown antibiotic, but I feel that the new genotype should be marked down on some mysterious aesthetic grounds".

  8. Unsound extrapolation by Geoffrey.landis · · Score: 4, Insightful
    The logic is not sound. First, modern humans have been in our current form for something like ten thousand generations; ten generations is trivial. Second, Framingham MA is a far too small a portion the human ecological range to extrapolate from-- unless this trend holds equally well in Addis Ababa, Singapore, Kiev, Kyoto, and the Brazilian rainforest, it has no meaning to human evolution whatsoever.

    Giving birth earlier and later menopause all sound like things that would improve selective fitness... but the question is, if they really are selected for, why weren't they selected for five thousand years ago? (Lower blood pressure and lower chloresterol are two that I can understand perhaps a little better-- the problems with heart trouble may have not been quite so much of a problem ten generations ago, when most humans did a lot more physical exercise just to stay alive).

    --
    http://www.geoffreylandis.com
    1. Re:Unsound extrapolation by Maxo-Texas · · Score: 2, Insightful

      I was going to post a similar comment, but it occured to me that much of the observed height difference between different groups of humans (except pygmies?) arise from differences in nutrition.
      The average Caucasian height was about the same 300 years ago.

      --
      She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
    2. Re:Unsound extrapolation by ztransform · · Score: 2, Insightful

      ten generations is trivial

      Hardly. Over the ten-thousand generations of which you speak how many of those had the ability to inter-racially marry and produce off-spring? How many of those went through an extremely rapid sea-change of moral thought through commercialisation and profiteering media companies with global reach?

      I think the next 3 generations will see the greatest changes known to man.

  9. Re:What will be the impact of docters by TSRX · · Score: 3, Insightful

    Ugly people = Morlocks?

  10. Re:Idocracy by pdabbadabba · · Score: 2, Insightful

    Note that the GP's fertility measures is just average number of offspring. This is probably just due to the well known fact that the better educated and the rich often choose to have fewer children. I seriously doubt awkwardness has anything to do with it.

  11. Idiocracy is classist bullshit by Anonymous Coward · · Score: 1, Insightful

    Class is not fixed. In my case, I'm the first generation in my family born in a middle-class household. First generation college, first generation Ph.D., first generation that earned more than $100,000 a year. My parent's generation was the first where everyone graduated high school. All grew up as dirt poor farm kids but over a few decades clawed their way up to middle-class. My grandparent's generation had one person graduate high school, the least formally educated person went to school for four years only, all were farmers or farm laborers. Early memory of Mom's: grandpa going through the farm's scrap metal heap to find enough to sell to buy her shoes.

    Now compare that to the rich. There's a saying that goes something like grandpa built the business, dad expanded it, junior bankrupted it. When you meet people born into riches, frequently (of course there are exceptions) you find lazy, spoiled children who do not have any ambition or curiosity. Their children often are similar, wasting the family fortune making the following generation either middle-class or poor. At any point though the family's class could go up or down, just like my family. I don't expect the next generation to move up as much as mine or my parent's; but they could still go up or down. Class is not fixed, despite the gaming of the system by the rich.

    Long story short: Idiocracy is classist bullshit that comforts rich wankers who desperately want to believe that they're rich because of some inherent superiority rather than opportunity and/or inheritance. Incipient speciation along class lines is ridiculous.

    1. Re:Idiocracy is classist bullshit by blahplusplus · · Score: 2, Insightful

      Except most people today are moving from ABSOLUTE poverty to a developed nation poor, does not mean that classes will not solidify over time as the rest of the world becomes fully developed like the west.

      In the west we have a reversing trend, more people are getting poorer.

      Social mobility cuts both ways (i.e. person in developed country gets job, x amount of workers lose their jobs in USA/Canada, Europe).

      And considering the amount of underemployed unviersity educated people in the USA and Canada it's quite obvious that they are backsliding (i.e. goign backwards).

      I just read a big article on it the other day I'll see if I can't find it.

    2. Re:Idiocracy is classist bullshit by Anonymous Coward · · Score: 1, Insightful

      "Half way" means nothing when 10% of the people own 90% of the wealth.

    3. Re:Idiocracy is classist bullshit by yndrd1984 · · Score: 2, Insightful

      "Half way" means nothing when 10% of the people own 90% of the wealth.

      It does mean that the classes aren't fixed - and that was the only claim I was making.

  12. Re:makes one wonder... by NoOneInParticular · · Score: 2, Insightful

    There is no genetic advantage to being sterile. Therefore, ants and bees do not exist.

  13. Re:Idocracy by Jeremiah+Cornelius · · Score: 2, Insightful

    It is also their job to go out of business, when they fail. But they have so many moles in your government (Geithner, Obama, etc.) that you will bail them out for the next 80 years - as they pay themselves bonuses off of your children's former college fund.

    You need to look up the definition of "Stockholm Syndrome" - then look hard in the mirror at yourself.

    --
    "Flyin' in just a sweet place,
    Never been known to fail..."
  14. Goldmanocracy by Anonymous Coward · · Score: 1, Insightful

    Goldman Sachs would have gone bankrupt, their investments and "products" shown to be mostly cons, if their employees weren't also in charge of the Fed and the Treasury.

    And you know it and so does the rest of the planet.

    Mr. Rogers asks, can you spell "bailouts", "insider trading", "front running", "flash trading", "influence peddling", "shell corporations", "naked shorts"?

    Goldman Sachs = the mother of all potential RICO cases..and it's coming, sooner or later.

    BTW, China has started allowing a lot of their high level investors to just default on these "products", better and more accurately termed "swindles", because they are realizing now they are mostly cons. This trend will accelerate and go beyond China, and China is switching to more durable type goods as investments overseas, mines, farm lands, energy sources. Their foray into dollar denominated paper "financial products" will be gradually slowing as they shift. They won't do it all at once, but they are and will continue to change.

  15. Re:Idocracy by 4D6963 · · Score: 2, Insightful

    Interesting! The thing about such debates is that all arguments are based on assumptions, assumptions which are difficult to verify. I'd be interested to see anything close to a graph showing the distribution of offsprings depending on household income/education btw!

    --
    You just got troll'd!
  16. Re:Personally, I think it is a matter of social cl by mabhatter654 · · Score: 2, Insightful

    He's specifically talking about the USA. It's much easier to buy Little Debbies at Walmart than to buy the proper food at Whole Foods (i.e. "whole paycheck"). Part of what makes civilization work is easy, cheap access to stored grain products... exactly what makes you fat. Rich folks have access to better quality food, they drink half-caf-soy-lattes instead of Coke, they get hour+ lunch times to eat nicely prepared salads, not 30 minutes drive-thru... ect, etc. They also get discounts for those expensive gyms (and again flexible work hours to USE them). At the top end, they farm their kids out to nannies so they have time to go do social things and look pretty.

  17. Re:Personally, I think it is a matter of social cl by PyroMosh · · Score: 5, Insightful

    There's no need to bring Rush Limbaugh into this.

    It's not universally true, but it is more or less an accepted fact.

    Fertility rates are inversely proportional to income.

    In the modern world there are a lot of reasons for this. The rich tend to have access to better education. therefore, they tend to try to start a career before a family (illustrated in comedic fashion by the Mike Judge movie Idiocracy). Then with their career dominating their lives, they usually only have a couple kids at the most.

    More wealthy folks have better access to birth control. Again, better education plays into this. On the extreme end of the spectrum, you have folks who have superstitious beliefs. That doesn't help keep their fertility rates down any...

    Economists and demographers have known about this correlation for centuries. And it's interesting because it goes across religions, across nationalities, race, and other factors. Poor Americans are just as likely to have a higher fertility rate as poor French, or Japanese. Poor Nigerians or Indians are even more likely because a poor American is fairly well off by Nigerian standards.

    Side Rant: The Israelis in particular are worried about this effect because Israel is a democracy. And the Israeli Palestinians have a fertility rate several times that of Israeli Jews. Again, the average Israeli Palestinian is much poorer than the average Israeli Jew.

    The Israelis are concerned because with the higher fertility rates of the Palestinian Israeli citizens, the Palestinians may become a majority in the "Jewish State" in a couple generations. This brings up all kinds of moral dilemmas for the Israeli government, who must try to balance it's commitment to a homeland for the Jews to it's commitment to democracy for all it's citizens.

    A few minutes of on the Google came up with these:
    http://www.economist.com/opinion/displaystory.cfm?story_id=14744915
    http://www.economist.com/sciencetechnology/displaystory.cfm?story_id=14164483
    http://www.cmaj.ca/cgi/content/full/177/8/846/F19
    http://en.wikipedia.org/wiki/Sub-replacement_fertility
    http://www.indexmundi.com/g/correlation.aspx?v1=67&v2=31&y=2004

    Also, I have no idea why you brought Rush Limbaugh into this. I'm about as progressive a character as you're likely to meet. I don't know anyone that disputes this data.

    Cause is another matter. Progressives would tend to contend that the reason is education, the nature of pre-industrialized societies, higher mortality rates among poor nations, the tempo of life in wealthy nations and classes.

    And Rush would say they all want their welfare checks or something.

    You're right about the lack of heredity for short-fatness though. It is environmental / cultural, not genetic.

  18. Re:What a headline by BikeHelmet · · Score: 2, Insightful

    I heard that stupid people also reproduce more, so clearly all the intelligent people will dry up by 2409 as well!

  19. Re:Population trends and the direction of evolutio by lul_wat · · Score: 2, Insightful

    She's 40, still hot and key point- has not yet had any kids! Yes that's right, it's the end of the line for her. If the hot chicks don't have kids- there will be no second generation of hot chicks. Meanwhile I see plenty of ugly chicks with babies walking around in Auckland New Zealand .. this boat is sinking.

    --
    Divide a cake by zero. Is it still a cake?