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Thread: Kin Selection and Sexual Selection

  1. #1 Kin Selection and Sexual Selection 
    Forum Masters Degree Golkarian's Avatar
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    It seems that in biology circles kin selection has one out as the source of altruism. But could sexual selection also be a possible route to it?


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    Forum Radioactive Isotope skeptic's Avatar
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    There are two main theories of the evolution of altruism.

    1. Kin selection. If you are altruistic to those closely related to you, it increases their chances of surviving to pass on their genes. Since you share many of those genes, it also passes on copies of your genes.

    2. Reciprocity. If you help those who are in a position to help you, they may return the favour and thus assist you in your chances of survival and successful reproduction, passing on your genes.

    Many evolutionists think there is a major problem here, in that humans are known to be altruistic to people who are not kin, and will not return the favour. For example : if you give money to a charity that treats AIDS victims in Africa, both principles are thwarted.

    Personally, I see no problem. We evolved altruism at a time when we lived in tribes and almost never saw another person who was not of that tribe. Thus, altruism to anyone in that tribal context met one or other of the two benefits listed above.

    Since evolution as a process is imperfect and follows the path of least resistance, it generated altruism towards all humans, rather than the more complex task of evolving a selective altruism. In other words, the fact that we are altruistic to people who are neither kin nor able to return a favour, is simply a fortunate accident.


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  4. #3  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
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    Skeptic is spot on. Although, I'll add that humans do seem much more altruistic towards kin than strangers. It's likely that both reciprocity and kin selection plays a part in selecting altruistic behavior.

    A human beings capacity to raise the children of deceased siblings is more obviously explained by kin selection. While small acts of kindness to strangers is easier to explain through reciprocity.
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  5. #4  
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    I think human altruism belongs in Psychology. It is a consequence of how our minds operate on anything. We create models of the world, including models of other people. These models are investments, real parts of our minds we don't like to throw away. I actually think of this in terms of synaptic survival. To avoid obsolescence and atrophy, synapses must maintain their models (circuits) by securing feedback through the real-world counterpart of the model.

    When we grieve for a death, we say it's like a part of ourselves suddenly torn out. An aching void. This describes the shutdown of a model. The unstimulated neurons are dying.

    We clean our fishtanks and water our gardens to strengthen models. These are altruistic acts. We play city-building "god-games", nurturing the virtual traffic flows and urban developments. We love sustainable and thriving models. We don't want the game to end. Because when the game ends, a part of mind ends with it.

    When one has a child and bonds with it, that inner model becomes quite dominant. It's like a perpetually looping script running in the brain, asking, "Where's the baby? Where's the baby? What does it need? Is is secure?" Hiring a sitter won't kill the thought complex. The "baby-simulation" just keeps running. This greedy model normally entrains a parent's every thought, so that loss of the baby would result in a kind of brain-death. Parents display some telling means of coping (or not) when they lose their children.
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    Forum Freshman Samuel P's Avatar
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    Could the evolution of altruism not be contributed to by both of those theories that Skeptic mentioned? Is there a reason why the two can't co exist?

    Also, is it possible that altruism has evolved to become part of our nature and that continues despite the social situation or the genetics of the people involved?
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  7. #6  
    Forum Radioactive Isotope skeptic's Avatar
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    Samuel

    You are totally right. It is probable that both mechanisms were at work. It is definitely a part of human nature now. However, the degree to which it impacts an individual is highly variable, and we all know people who are so bloody mean they almost totally lack altruism!

    Golkarian also mentioned sexual selection. It is possible that this is currently a mechanism, in that a woman might favour a man as partner if he displays altruism. However, that mechanism would not have kicked in until after altruism was a part of human nature, since it has to be first seen as desirable. ie. sexual selection may keep it going, but would not have initiated the evolution of altruism.
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    Forum Masters Degree Golkarian's Avatar
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    Quote Originally Posted by skeptic
    Samuel

    You are totally right. It is probable that both mechanisms were at work. It is definitely a part of human nature now. However, the degree to which it impacts an individual is highly variable, and we all know people who are so bloody mean they almost totally lack altruism!

    Golkarian also mentioned sexual selection. It is possible that this is currently a mechanism, in that a woman might favour a man as partner if he displays altruism. However, that mechanism would not have kicked in until after altruism was a part of human nature, since it has to be first seen as desirable. ie. sexual selection may keep it going, but would not have initiated the evolution of altruism.
    But wouldn't that be true of the other processes as well, eg a mutation must arise before it can be selected for?
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    Re sexual selection

    A mutation must confer an advantage for it to be selected for. For a trait to be selected for sexually, it must be seen to be desirable. For altruism to be perceived as desirable, and hence make an individually more attractive, it must already be appreciated.

    If altruism simply arose as a random mutation, there would be no reason for it to be perceived as desirable, and hence would not be selected for sexually. Only after it had become desirable would sexual selection kick in.
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  10. #9  
    Forum Masters Degree Golkarian's Avatar
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    Quote Originally Posted by skeptic
    Re sexual selection

    A mutation must confer an advantage for it to be selected for. For a trait to be selected for sexually, it must be seen to be desirable. For altruism to be perceived as desirable, and hence make an individually more attractive, it must already be appreciated.

    If altruism simply arose as a random mutation, there would be no reason for it to be perceived as desirable, and hence would not be selected for sexually. Only after it had become desirable would sexual selection kick in.
    i see
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  11. #10  
    Forum Masters Degree Golkarian's Avatar
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    However, could it be possible that kin selection started it off and then sexual selection allowed it to be spread to non-relatives?
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  12. #11  
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    Life VS unlife is a hard enough battle in itself, if everything in nature turned on eachother and looked upon everything as an enemy life would never develop.

    However allowing the weak to survive is also a threat to the survival of life, so survival of the fittest is needed.

    I know i know, evolution dont have a "mind" of its own or a will But in the large scale of things altruism is ultimately beneficial as a whole.

    The way i see it, all life must spread more life and altruism can grant you valuable allies. As ive understood it altruism is especially present in coral reefs? Where lots of life forms help eachother? The only large scale importance is that life wins over unlife. To bad life is badly outnumbered by.... well... nothingness, death, chaos and destruction.
    A lie is a lie even if everyone believes it. The truth is the truth even if nobody believes it. - David Stevens
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    Quote Originally Posted by Golkarian
    But wouldn't that be true of the other processes as well, eg a mutation must arise before it can be selected for?
    A mutation? You guys are discussing this as if it were solely genetic. Most of what you are discussing here is cultural. If there is an ethic of altruism toward strangers among the people participating in this discussion, or in western society as a whole, it doesn't mean that's true for all people everywhere. In fact, I would doubt that very much.
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  14. #13  
    Forum Radioactive Isotope skeptic's Avatar
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    Harold

    Altruism is indeed universal, though only conditionally so.

    The conditions are :

    1. In every society, there is a portion of the population that is essentially lacking conscience - hence not altruistic. However, in all societies, the majority are altruistic. Some surveys put the conscienceless at about 10%.

    2. The form that altruism takes is highly variable. For example : in the highlands of Papua New Guinea, they have a social system called wantok (pigeon for one talk, or sharing a language). Wantok means that those who belong to the same language group are altruistic towards each other, but they are taught that those outside that group are less than human, and altruism towards those outsiders is limited. In the society I belong to, people give money to help the dispossessed in Haiti. Thus, our altruism is different.

    However, taking those two conditions into account, altruism is, indeed, universal.
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  15. #14  
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    Quote Originally Posted by skeptic
    Harold

    Altruism is indeed universal, though only conditionally so.

    The conditions are :

    1. In every society, there is a portion of the population that is essentially lacking conscience - hence not altruistic. However, in all societies, the majority are altruistic. Some surveys put the conscienceless at about 10%.

    2. The form that altruism takes is highly variable. For example : in the highlands of Papua New Guinea, they have a social system called wantok (pigeon for one talk, or sharing a language). Wantok means that those who belong to the same language group are altruistic towards each other, but they are taught that those outside that group are less than human, and altruism towards those outsiders is limited. In the society I belong to, people give money to help the dispossessed in Haiti. Thus, our altruism is different.

    However, taking those two conditions into account, altruism is, indeed, universal.
    Well, sure, society wouldn't work otherwise. I was referring specifically to altruism toward people outside the group. It should be obvious that is not universal. The history of mankind is a history of war.
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  16. #15  
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    The theories on the evolution of altruism attempt to question what environmental forces were responsible in driving humans to develop the faculty of selflessness and sacrifice, which is always to the detriment of oneself—typically regarded as “behavioural theories”. However, in my view, this is a subject best investigated when coupled to subjects like neurobiology: using neuronal circuitry analysis, and computational modelling, which provide us with copious amounts of relatively unbiased information related to the true causes and reasons for altruism.

    Neurobiology suggests that altruism is basic and hard-wired into the human brain, selectively activating particular regions of the brain (i.e. subgenual cortex) intimately related to social attachment and bonding, and allowing for altruistic subjects to experience corresponding pleasures.

    Additionally, the recent discovery of mirror neurons—a neuron that fires both during personal action and when observing the same action performed by another—have raised the possibility that these are in fact involved in empathy. As such, the act of giving a favour without expecting a favour in return can be explained easily—a given favour to another will activate a region associated with rewards in his brain (mesolimbic pathway, for example). Mirror neurons will subsequently fire and activate a similar region of the brain in the altruistic individual, therefore allowing him to experience a feeling of pleasure similar to that experienced when being given the favour. Consequently, he continues to do it, despite receiving nothing in return. The divergence in the activity of mirror neurons between two individuals could also be the cause for the discrepancy in their respective altruistic levels.
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  17. #16  
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    Well, if you just try to explain it by neurobiology, you are going to miss a big part of the picture, because all societies have developed rules and customs about where, when, how and toward whom the altruism is expressed. And those rules are anything but universal.
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  18. #17  
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    Quote Originally Posted by Harold14370
    Well, if you just try to explain it by neurobiology, you are going to miss a big part of the picture, because all societies have developed rules and customs about where, when, how and toward whom the altruism is expressed. And those rules are anything but universal.
    That’s the reason why I said “coupled to neurobiology”. However, my view is that neurobiology is there to hold up or refute any claim made by behaviourists. Behaviourists provide neurobiologists with the hypotheses needed to selectively target particular avenues of research. That said, most of the core pathways associated with altruism and selfishness lie outside the boundaries of mere society. This means that there exists a core within neurobiology that involves all humans, irrespective of their culture or background—society and the environment will influence the degree and manner of expression, but not the expression itself. These attributes are associated with basic, hard-wired actions that reside within primitive regions of the brain.
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