6 ms·

If I asked you "Why do you take your hand off a hot stove?" you might say because it hurts. But the fact that it hurts for us when we put our hand on the stove

If I asked you "Why do you take your hand off a hot stove?" you might say because it hurts. But the fact that it hurts for us when we put our hand on the stove is our genes trying to keep themselves alive, because otherwise they risk being killed. In the same way, a person might say they had an affair for whatever reason, but really its their genes who want to be able to pass on themselves. (Edited for clarity.)

deleted 14y ago
[deleted]
justincormack 14y ago
Not really. That's a theory and it is one that is hard to disprove experimentally. It is a much stronger theory than evolution, saying that every action is correctly designed to optimise gene transmission. Essentially it is trying to say that we are at a global maximum in a space that is probably more nonlinear. In fact our genes may well be suboptimal in some respects even if you think they have "control". The contortions people go through to try to justify homosexuality as a genetic thing are one example of many. In fact diversity is an advantage in a varying environment so many traits must be suboptimal.
- mvleming 14y ago
  I completely agree with you. I don't believe that every action is correctly designed to optimize gene transmissions and I think you put it into very eloquent words with: "it is trying to say that we are at a global maximum in a space that is probably more nonlinear." However, I think that there are certain actions that we take that are clearly defined by our genetics, like the fact that we eat, or that we have sex. And having affairs is one of those.
  - justincormack 14y ago
    I agree absolutely it is more likely. And I read The Selfish Gene. But how could you disprove that theory? it is sort of too obviously true, if you see what I mean. Which is why I brought up the homosexuality counterexample. So I don't think it should be taken as undeniable, even though it is plausible.
    - mvleming 14y ago
      I see what you're trying to get at. You're saying that "x% of children are not genetically related to their fathers because women have affairs to increase the competition for her egg" is a theory, not to be taken as something true. I didn't mean to make myself sound like that I was saying it was. I was just suggesting something and I agree with you: it is plausible, but it is still a theory at the end of the day. We're on the same page. :)
      - maskedinvader 14y ago
        I rarely read discussions between 2 people beyond the 3rd or 4th reply, but this one kept me wanting to see how this goes, very well concluded. This is the reason I love HN, quality of discussion is much better than any other place.
  - javert 14y ago
    That we have sex is defined by our genes; who we have sex with is a choice we make by thinking about it, not something pre-encoded by our genes, as you are trying to say. Which actually makes sense given your premises. A good evolutionary "strategy" would be to evolve brains that can make choices far more complex (literally, inelligently) than what can be pre-encoded by genes that change slowly and mutate randomly. In summary, you are implying that when you have an affair, it's not a choice, but it's determined by your genes. Thus, it's not a moral issue; you have no choice. Thus, you can justify having any particular affair by claiming "genes," and you should just forgive any particular affair your wife has for the same reason. And I'm saying, no, it's a choice.
    - mvleming 14y ago
      There was actually a study that showed female rats are more attracted to (read: had sex with) male rats with very different immune systems. The way she senses this is by the pheromone (smell) he gives off and as a consequence, her offspring have stronger immune systems. In other words, this study suggests at least to some degree we don't even choose who we have sex with. Haha.
      - javert 14y ago
        The purpose of my comment was to point out that humans have a (sophisticated) brain, something critical that you had overlooked, and you still seem to have missed that.
        mvleming 14y ago
        You argued that "who we have sex with is a choice we make by thinking about it, not something pre-encoded by our genes." I was trying to suggest maybe the opposite is true to some extent by sharing that study regarding the rats with you. Female rats unconsciously have sex with male rats whose pheromones smell like their immune systems are very different, in other words, who they select as mates is something pre-encoded in their genes. Are you arguing that because we have brains we can 'override' what our genes would otherwise have us do?
- hackinthebochs 14y ago
  >Not really. That's a theory and it is one that is hard to disprove experimentally. It is a much stronger theory than evolution This isn't right at all. The idea that our behaviors are shaped in ways that increase our fitness follows necessarily from the theory of evolution. If we believe that behaviors are influenced at all by our genes, then behaviors that are detrimental get weeded out. What's left over was more fit for that environment. There is mountains of evidence that our behavior is affected by our genes. That is not to say that all behaviors are optimal at all times. For one, our environment has changed monumentally in just the last few hundred years. Behaviors that were optimal back then may not be now. Also, there are multiple levels when considering optimal behavior. Behavior that is suboptimal for the individual can still be optimal for the gene causing that behavior. Homosexuality for example. It may be true that the homosexuality gene is optimally propagated when its in 10% of the population (look up evolutionary stable strategy). I recently read about a study that claimed the male homosexuality gene when in a woman greatly increased her sexual attractiveness and sexual aggressiveness. When it's in a man it makes him homosexual. I'm sure its too early to take this as fact, but this scenario would lead to a non-zero optimal distribution of that gene in the population.
  - ckg 14y ago
    According to this article (http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe120612.php http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe12061...) homosexuality is epigenetic and not genetic (i.e. is not related to a specific gene, but to chemical differences that affect the expression of genes).
  - dalke 14y ago
    > The idea that our behaviors are shaped in ways that increase our fitness follows necessarily from the theory of evolution. This is a misreading of evolution. To start with, we are not optimal. Not even locally optimal. No species is. Who is the optimal human? Is that person alive today? Second, you haven't considered timescale. You say "get weeded out". How long does that process take? Suppose all behaviors are directly influenced by genes. A low-impact detrimental behavior - let's say a tendency to pick one's nose in public - faces essentially no evolutionary pressure, and so will persist effectively forever. Rather, it would be long enough as to make it nearly impossible to tell if that behavior is a beneficial or detrimental one. How can you tell that the behavior you are examining increases fitness or decreases fitness but happens to be in the same genome as something else which greatly increases fitness? Suppose that a subpopulation of humans acquires the 'hunk/babe' mutation and also acquires the nose picking mutation. The first gives an strong genetic advantage, and the second a very minor disadvantage. Over 1,000 years, this subpopulation dominates the overall human genetic makeup. Some researchers then point to the increase in nose picking in the general population and conjecture that nose picking must have conferred some genetic advantage. But this is wrong. Nose picking came along for the ride. (For purposes of that thought experiment, assume also that the environment is unchanged during that time.) Third, the coupling between behavior and genes can be extremely tenuous. 300 years ago you could look at European populations and conclude that they were genetically predisposed towards monarchy. Some believed that this was the natural order of things. Where's the gene for democracy? 1000 years ago you could conclude that there was a genetic predisposition towards Catholicism. What genetics caused people to chose that over, say, Zoroastrianism?

deleted 14y ago

[deleted]

justincormack 14y ago

Not really. That's a theory and it is one that is hard to disprove experimentally. It is a much stronger theory than evolution, saying that every action is correctly designed to optimise gene transmission. Essentially it is trying to say that we are at a global maximum in a space that is probably more nonlinear. In fact our genes may well be suboptimal in some respects even if you think they have "control". The contortions people go through to try to justify homosexuality as a genetic thing are one example of many. In fact diversity is an advantage in a varying environment so many traits must be suboptimal.

mvleming 14y ago
I completely agree with you. I don't believe that every action is correctly designed to optimize gene transmissions and I think you put it into very eloquent words with: "it is trying to say that we are at a global maximum in a space that is probably more nonlinear." However, I think that there are certain actions that we take that are clearly defined by our genetics, like the fact that we eat, or that we have sex. And having affairs is one of those.
- justincormack 14y ago
  I agree absolutely it is more likely. And I read The Selfish Gene. But how could you disprove that theory? it is sort of too obviously true, if you see what I mean. Which is why I brought up the homosexuality counterexample. So I don't think it should be taken as undeniable, even though it is plausible.
  - mvleming 14y ago
    I see what you're trying to get at. You're saying that "x% of children are not genetically related to their fathers because women have affairs to increase the competition for her egg" is a theory, not to be taken as something true. I didn't mean to make myself sound like that I was saying it was. I was just suggesting something and I agree with you: it is plausible, but it is still a theory at the end of the day. We're on the same page. :)
    - maskedinvader 14y ago
      I rarely read discussions between 2 people beyond the 3rd or 4th reply, but this one kept me wanting to see how this goes, very well concluded. This is the reason I love HN, quality of discussion is much better than any other place.
- javert 14y ago
  That we have sex is defined by our genes; who we have sex with is a choice we make by thinking about it, not something pre-encoded by our genes, as you are trying to say. Which actually makes sense given your premises. A good evolutionary "strategy" would be to evolve brains that can make choices far more complex (literally, inelligently) than what can be pre-encoded by genes that change slowly and mutate randomly. In summary, you are implying that when you have an affair, it's not a choice, but it's determined by your genes. Thus, it's not a moral issue; you have no choice. Thus, you can justify having any particular affair by claiming "genes," and you should just forgive any particular affair your wife has for the same reason. And I'm saying, no, it's a choice.
  - mvleming 14y ago
    There was actually a study that showed female rats are more attracted to (read: had sex with) male rats with very different immune systems. The way she senses this is by the pheromone (smell) he gives off and as a consequence, her offspring have stronger immune systems. In other words, this study suggests at least to some degree we don't even choose who we have sex with. Haha.
    - javert 14y ago
      The purpose of my comment was to point out that humans have a (sophisticated) brain, something critical that you had overlooked, and you still seem to have missed that.
      - mvleming 14y ago
        You argued that "who we have sex with is a choice we make by thinking about it, not something pre-encoded by our genes." I was trying to suggest maybe the opposite is true to some extent by sharing that study regarding the rats with you. Female rats unconsciously have sex with male rats whose pheromones smell like their immune systems are very different, in other words, who they select as mates is something pre-encoded in their genes. Are you arguing that because we have brains we can 'override' what our genes would otherwise have us do?
hackinthebochs 14y ago
>Not really. That's a theory and it is one that is hard to disprove experimentally. It is a much stronger theory than evolution This isn't right at all. The idea that our behaviors are shaped in ways that increase our fitness follows necessarily from the theory of evolution. If we believe that behaviors are influenced at all by our genes, then behaviors that are detrimental get weeded out. What's left over was more fit for that environment. There is mountains of evidence that our behavior is affected by our genes. That is not to say that all behaviors are optimal at all times. For one, our environment has changed monumentally in just the last few hundred years. Behaviors that were optimal back then may not be now. Also, there are multiple levels when considering optimal behavior. Behavior that is suboptimal for the individual can still be optimal for the gene causing that behavior. Homosexuality for example. It may be true that the homosexuality gene is optimally propagated when its in 10% of the population (look up evolutionary stable strategy). I recently read about a study that claimed the male homosexuality gene when in a woman greatly increased her sexual attractiveness and sexual aggressiveness. When it's in a man it makes him homosexual. I'm sure its too early to take this as fact, but this scenario would lead to a non-zero optimal distribution of that gene in the population.
- ckg 14y ago
  According to this article (http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe120612.php http://www.eurekalert.org/pub_releases/2012-12/nifm-sfe12061...) homosexuality is epigenetic and not genetic (i.e. is not related to a specific gene, but to chemical differences that affect the expression of genes).
- dalke 14y ago
  > The idea that our behaviors are shaped in ways that increase our fitness follows necessarily from the theory of evolution. This is a misreading of evolution. To start with, we are not optimal. Not even locally optimal. No species is. Who is the optimal human? Is that person alive today? Second, you haven't considered timescale. You say "get weeded out". How long does that process take? Suppose all behaviors are directly influenced by genes. A low-impact detrimental behavior - let's say a tendency to pick one's nose in public - faces essentially no evolutionary pressure, and so will persist effectively forever. Rather, it would be long enough as to make it nearly impossible to tell if that behavior is a beneficial or detrimental one. How can you tell that the behavior you are examining increases fitness or decreases fitness but happens to be in the same genome as something else which greatly increases fitness? Suppose that a subpopulation of humans acquires the 'hunk/babe' mutation and also acquires the nose picking mutation. The first gives an strong genetic advantage, and the second a very minor disadvantage. Over 1,000 years, this subpopulation dominates the overall human genetic makeup. Some researchers then point to the increase in nose picking in the general population and conjecture that nose picking must have conferred some genetic advantage. But this is wrong. Nose picking came along for the ride. (For purposes of that thought experiment, assume also that the environment is unchanged during that time.) Third, the coupling between behavior and genes can be extremely tenuous. 300 years ago you could look at European populations and conclude that they were genetically predisposed towards monarchy. Some believed that this was the natural order of things. Where's the gene for democracy? 1000 years ago you could conclude that there was a genetic predisposition towards Catholicism. What genetics caused people to chose that over, say, Zoroastrianism?