Evolution is cleverer than you are
"Evolution is cleverer than you are."
-- evolutionary biologist Leslie Orgel
The idea that men and women are psychologically different on a biological level has been a controversial topic on this blog, but it doesn't come as a surprise to most people. One big surprise that has come out of the last 30 years of research is how smart genes are and how fast evolution happens. Scientists used to think that natural selection was slow and clumsy. We now see it as faster and more precise than we had imagined.
Humans have continued to evolve in the last 70,000 years that we've been "behaviorally modern." For example, three separate human populations have evolved some ability to digest milk sugar even as adults. Without necessarily affirming any individual claim, Wade recounts various hypotheses about the recent evolution of new traits within certain populations. The higher IQ of European Jews might be due in part to selection pressure put on a population that was forced to survive through business and scholarship rather than labor. The genetic diseases that Jews are prone to might be a side effect of genes that code for less-limited neuronal development. Two genes implicated in brain development have arisen recently, 40 KYA (thousand years ago) and 6 KYA and spread through Indo-European and East Asian populations. Other ethnic groups probably evolved other genes that do the same beneficial thing for brain development that these genes do, so they don't prove any sort of racial superiority. (Nicolas Wade, Before the Dawn)
Our genome includes recent genetic adaptations to diseases, ice ages, and other stressors. You may have heard that the genes for sickle cell anemia protect people from malaria. So does favaism, a genetic susceptibility to fava beans. (Survival of the Sickest, Sharon Moalem. This one is a little iffy overall but the instances of adaptation to changes in the environment over the last 70K years is pretty good.)
Fathers imprint the X-chromosomes of their sperm on a molecular level, causing certain genes to express themselvesfathers actually alter the X-chromosomes that they pass along to make them more "feminine." The X-chromosome in a woman's egg is just as likely to end up in a boy's genes and a girl's, but the X-chromosomes in a father's sperm will only ever express themselves in girls. So men have evolved a system for (slightly) adjusting the X-chromosomes that they put in their spermatozoa. You can see this effect among women born with just one X-chromosome. Those whose X chromosome comes from the father test higher on certain "feminine" traits: That's just the wildest example, but he also documents many ways in which genes and hormones affect behavior. Pinker also shows how the brain is predisposed to learn some lessons and not others. Behaviorists viewed the brain as a sort of neutral learning machine, but it's not neutral at all. We're soft-coded to learn certain things (e,g, speech), coded with the neutral potential to learn other things (e.g., writing), and coded with a resistance to learning other things (e.g., abstaining from sex). (Pinker, Blank Slate)
A woman's brain, far from being a neutral medium that society can mold as it likes, develops through the life cycle, mediated by hormones, to (for example) make her more intuitive and to get her to bond with a mate and especially with her children. The same can be said for a man's brain, but there's a lot more going on hormonally for a woman than for a man. (Brizendine, Female Brain)
Our sexual instincts and morphology are markedly different from those found in our nearest relatives. In terms of behavior, a huge disconnect from previous sexual politics is that males and females bond as couples and raise children together. In terms of morphology, a female's sexual display now comprises everything from her hair to her toenails, and is always active, compared to a chimp female's display, which is associated only with estrus and is frankly genital-focused. A woman's hidden ovulation seemingly disconnects copulation from reproduction. These and other changes are startling and recent. (Leonard Shlain, Sex Time and Power. This one gets pretty iffy toward the end.)
I've already mentioned the ability of women to detect the immune-system genes of their mates and to seek other men if their mates' genes are too similar to their own.
The more we learn about the brain, about genes, and about our species genetic heritage the more clear it is that our genes, hormones, and brain structures are doing a lot of precise evolution, interaction, and mediation, far more than we used to think possible.
-- evolutionary biologist Leslie Orgel
The idea that men and women are psychologically different on a biological level has been a controversial topic on this blog, but it doesn't come as a surprise to most people. One big surprise that has come out of the last 30 years of research is how smart genes are and how fast evolution happens. Scientists used to think that natural selection was slow and clumsy. We now see it as faster and more precise than we had imagined.
Humans have continued to evolve in the last 70,000 years that we've been "behaviorally modern." For example, three separate human populations have evolved some ability to digest milk sugar even as adults. Without necessarily affirming any individual claim, Wade recounts various hypotheses about the recent evolution of new traits within certain populations. The higher IQ of European Jews might be due in part to selection pressure put on a population that was forced to survive through business and scholarship rather than labor. The genetic diseases that Jews are prone to might be a side effect of genes that code for less-limited neuronal development. Two genes implicated in brain development have arisen recently, 40 KYA (thousand years ago) and 6 KYA and spread through Indo-European and East Asian populations. Other ethnic groups probably evolved other genes that do the same beneficial thing for brain development that these genes do, so they don't prove any sort of racial superiority. (Nicolas Wade, Before the Dawn)
Our genome includes recent genetic adaptations to diseases, ice ages, and other stressors. You may have heard that the genes for sickle cell anemia protect people from malaria. So does favaism, a genetic susceptibility to fava beans. (Survival of the Sickest, Sharon Moalem. This one is a little iffy overall but the instances of adaptation to changes in the environment over the last 70K years is pretty good.)
Fathers imprint the X-chromosomes of their sperm on a molecular level, causing certain genes to express themselvesfathers actually alter the X-chromosomes that they pass along to make them more "feminine." The X-chromosome in a woman's egg is just as likely to end up in a boy's genes and a girl's, but the X-chromosomes in a father's sperm will only ever express themselves in girls. So men have evolved a system for (slightly) adjusting the X-chromosomes that they put in their spermatozoa. You can see this effect among women born with just one X-chromosome. Those whose X chromosome comes from the father test higher on certain "feminine" traits: That's just the wildest example, but he also documents many ways in which genes and hormones affect behavior. Pinker also shows how the brain is predisposed to learn some lessons and not others. Behaviorists viewed the brain as a sort of neutral learning machine, but it's not neutral at all. We're soft-coded to learn certain things (e,g, speech), coded with the neutral potential to learn other things (e.g., writing), and coded with a resistance to learning other things (e.g., abstaining from sex). (Pinker, Blank Slate)
A woman's brain, far from being a neutral medium that society can mold as it likes, develops through the life cycle, mediated by hormones, to (for example) make her more intuitive and to get her to bond with a mate and especially with her children. The same can be said for a man's brain, but there's a lot more going on hormonally for a woman than for a man. (Brizendine, Female Brain)
Our sexual instincts and morphology are markedly different from those found in our nearest relatives. In terms of behavior, a huge disconnect from previous sexual politics is that males and females bond as couples and raise children together. In terms of morphology, a female's sexual display now comprises everything from her hair to her toenails, and is always active, compared to a chimp female's display, which is associated only with estrus and is frankly genital-focused. A woman's hidden ovulation seemingly disconnects copulation from reproduction. These and other changes are startling and recent. (Leonard Shlain, Sex Time and Power. This one gets pretty iffy toward the end.)
I've already mentioned the ability of women to detect the immune-system genes of their mates and to seek other men if their mates' genes are too similar to their own.
The more we learn about the brain, about genes, and about our species genetic heritage the more clear it is that our genes, hormones, and brain structures are doing a lot of precise evolution, interaction, and mediation, far more than we used to think possible.