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selflessness cheats natural selection


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a member of species taking care of another member's well being at the expense of it's own benefit, health, or even life, is a destructive trait to the first member..

 

why haven't sacrificial help in all it's forms die out? how did it escape natural selection?

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It's more about helping your genes than helping you, meaning sacrificing yourself for the good of your relatives makes sense. (Or whoever takes the emotional place of "your relatives")

 

A behavior doesn't have to work out for the "best" in every instance to be selected for. A fight or flight response can get you killed, sometimes, but it's still useful over all. Similarly, helping out the group is usually a net benefit, even if that tendency occasionally makes you jump on the grenade, so to speak.

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a member of species taking care of another member's well being at the expense of it's own benefit, health, or even life, is a destructive trait to the first member..

 

why haven't sacrificial help in all it's forms die out? how did it escape natural selection?

 

You are speaking about altruism. This has been extensively studied because it does, on the surface, present a problem for natural selection. However, this was first solved for social insects and the solution is general enough to apply to other altruistic situations.

 

As Sisyphus has pointed out, it is a about alleles (forms of genes). Every diploid organism has 2 alleles for each gene -- one from the father and one from the mother. But this means that you share alleles with your parents, your siblings, and your offspring. In fact, you share half your alleles with each. So, if your sacrifice allows 2 of any of these -- parents, siblings, or offspring -- to survive, then the number of your alleles stays the same in the population. If you save more, then the number of your alleles actually increases.

 

So, if you have an allele for self-sacrifice, that allele can increase in the population as long as the possessors of the allele save more individuals with that allele than is lost when the possessors die.

 

This works best when the population is a small clan, tribe, or group where all the members are some form of relative. That means you have many copies of your alleles in the population. Saving members of the population ensures the propagation of that allele.

 

Now, like many evolutionary traits, humans have extrapolated altruism that works for relatives to a larger group of people who are not related. Thus we have military personnel sacrificing themselves for a nation -- most of whom are not their relatives. Or people sacrificing themselves for a religious group or some other ideal.

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In fact, you share half your alleles with each. So, if your sacrifice allows 2 of any of these -- parents, siblings, or offspring -- to survive, then the number of your alleles stays the same in the population. If you save more, then the number of your alleles actually increases.

 

You also want to consider the possibility that they are related to you in more ways than one. In fact, given that we share a common ancestor, everyone is to some extent related to everyone. And given the historical tribal groups you mentioned, you could expect people around you to be quite closely related to you via multiple relatives, even if not a direct relative.

 

Also, compare the reproductive potential of the ones you are saving compared to yourself. If you had to choose whether to save a child or an old man, would you not choose the child?

 

However, we do not go about calculating exactly how closely related someone is to us, and in fact we wouldn't know anyhow. However, the people we are closest to are usually related to us more strongly.

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I would submit that it is sometimes difficult to draw a line between selfish and selfless acts, even without considering whether it benefits the large Self of shared genes. We are social beings, often susceptible to the need for approval. The "selfless" act can be done with one eye on the resume. Is it too cynical to believe there is no such thing as a totally selfless act?

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lucaspa was the only one who answered the question directly.

 

selfless acts are good for the group, but bad for the unit or element.

is that why selflessness should kept as a mutation? it seems to me some are saying yes.

but we forgot that natural selection keeps the helpful traits around because they help their carriers, it's like the law of genes and natural selection is:"if it kills you, it dies with you"..

yes selflessness raises the groups survival rate, but how does it maintain itself in the group? the selfless should die and selflessness should die with them, but that's not the case..

 

lucaspa cleared it out by building on what sysiphus said, that the genes of selflessness are ok with you dead, as long as on the other hand of your death MORE selflessness gene's survive, so the selflessness gene in one element or unit helps the other genes of selflessness in other genes of selflessness in other units of the group, which actually make that gene(or allele) more effective in spreading than other genes which rely on their carrying unit to spread.

so if five carriers of a longer neck for food out of ten units were in danger of death, they will die and the long neck gene will lose 50% of it's capacity.

if the same scenario was repeated for selfless gene carriers then one or two of the ten would sacrifice themselves for the group and the selfless gene would lose 10-20% of its capacity.

 

or the other five would jump in and they would all die out, making selfless ness differ from blatent stupidity by being combined with some intelligence.

 

 

well, that makes things alot much clearer, though it doesn't answer the core question, the first time ever the selflessness gene was introduced, how did it spread from one element to another and a third till it had enough to compensate its self destruction?

 

if normal genes spread through groups at a linear rate by reproduction, and the selfless gene maintain and spread itself through a group exponentially through sacrificial behavior (just like y=x^2) then how did y reach the increasing interval, when it has to start from zero?(and pass through x<1, which is decreasing)

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well, that makes things alot much clearer, though it doesn't answer the core question, the first time ever the selflessness gene was introduced, how did it spread from one element to another and a third till it had enough to compensate its self destruction?

 

if normal genes spread through groups at a linear rate by reproduction, and the selfless gene maintain and spread itself through a group exponentially through sacrificial behavior (just like y=x^2) then how did y reach the increasing interval, when it has to start from zero?(and pass through x<1, which is decreasing)

 

A genetic mutation can start from zero and multiply even if it has only negative effects, carried simply by chance and with support of all the positive genes. They are "all in the same boat" with each individual, the good genes and the bad, so there is a possibility for any gene to get established to some degree in a given population before it is really even tested.

Edited by J.C.MacSwell
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well, that makes things alot much clearer, though it doesn't answer the core question, the first time ever the selflessness gene was introduced, how did it spread from one element to another and a third till it had enough to compensate its self destruction?

 

Its called genetic drift, basically the role chance plays in inheritance of traits. Genetic drift is more complicated than idealized natural selection, and its effects are mostly with small populations and with traits that are close to neutral. For example, if your population size is two, the genes that get passed on are going to be almost entirely due to chance and even significantly detrimental genes would have a good chance of reaching fixation.

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a member of species taking care of another member's well being at the expense of it's own benefit, health, or even life, is a destructive trait to the first member..

 

why haven't sacrificial help in all it's forms die out? how did it escape natural selection?

 

 

This is just talking off the top of my head, so correct me if I am wrong.

 

I don't see a lot of children or even teenagers being selfless to the point of putting their lives at risk, so perhaps the "selfless" gene doesn't come into play until an individual reaches adulthood, presumably after reproduction.

 

In evolutionary terms, it doesn't matter how long a person lives only how many sucessful offspring the person has, so it doesn't matter if the person sacrifices him/herself after the genes have been passed on.

 

If this is indeed the case, the "selfless" gene could easily be passed on like the dominant genetic disorders that don't effect individuals until middle age such as Huntington Disease.

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In evolutionary terms, it doesn't matter how long a person lives only how many sucessful offspring the person has, so it doesn't matter if the person sacrifices him/herself after the genes have been passed on.

Unless (of course) his/her sacrifice offers a better chance for their offspring to have offspring of their own, or further, if his/her sacrifice increases the chances of survival of their genetic relatives and their children.

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Unless (of course) his/her sacrifice offers a better chance for their offspring to have offspring of their own, or further, if his/her sacrifice increases the chances of survival of their genetic relatives and their children.

 

Agreed, which of course would select for the "selfless" gene.

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lucaspa was the only one who answered the question directly.

 

selfless acts are good for the group, but bad for the unit or element.

is that why selflessness should kept as a mutation? it seems to me some are saying yes.

but we forgot that natural selection keeps the helpful traits around because they help their carriers, it's like the law of genes and natural selection is:"if it kills you, it dies with you"..

yes selflessness raises the groups survival rate, but how does it maintain itself in the group? the selfless should die and selflessness should die with them, but that's not the case..

 

lucaspa cleared it out by building on what sysiphus said, that the genes of selflessness are ok with you dead, as long as on the other hand of your death MORE selflessness gene's survive, so the selflessness gene in one element or unit helps the other genes of selflessness in other genes of selflessness in other units of the group, which actually make that gene(or allele) more effective in spreading than other genes which rely on their carrying unit to spread.

so if five carriers of a longer neck for food out of ten units were in danger of death, they will die and the long neck gene will lose 50% of it's capacity.

if the same scenario was repeated for selfless gene carriers then one or two of the ten would sacrifice themselves for the group and the selfless gene would lose 10-20% of its capacity.

 

or the other five would jump in and they would all die out, making selfless ness differ from blatent stupidity by being combined with some intelligence.

 

 

well, that makes things alot much clearer, though it doesn't answer the core question, the first time ever the selflessness gene was introduced, how did it spread from one element to another and a third till it had enough to compensate its self destruction?

 

if normal genes spread through groups at a linear rate by reproduction, and the selfless gene maintain and spread itself through a group exponentially through sacrificial behavior (just like y=x^2) then how did y reach the increasing interval, when it has to start from zero?(and pass through x<1, which is decreasing)

 

The thing to note here is that altruism towards closely related members of a social group is only a step away from caring for and protecting offspring. So it's not starting with "zero" altruism. It's starting with self-sacrificing behaviour towards offspring and extending that to members of a social group. Also, social animals often police each other so that selfish behaviour is discouraged. Even worker bees will physically punish other workers for selfish behaviour.

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  • 3 weeks later...

Don't insects like bees and ants use a genetic 'trick' so that, for each individual, their siblings are likely to be more genetically similar to them then their offspring would be? So, comparing altruism in colony-insects with human altruism doesn't quite work?

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Dak - I'm not entirely sure what you're referring to, but I'd suspect that any differences we find are more rationalizations than rational difference. Again, though... I didn't really follow the point.

 

In the meantime, an interesting article published today... Survival of the Kindest. :)

 

 

http://www.sciencedaily.com/releases/2009/12/091208155309.htm

Researchers at the University of California, Berkeley, are challenging long-held beliefs that human beings are wired to be selfish. In a wide range of studies, social scientists are amassing a growing body of evidence to show we are evolving to become more compassionate and collaborative in our quest to survive and thrive.

 

In contrast to "every man for himself" interpretations of Charles Darwin's theory of evolution by natural selection, Dacher Keltner, a UC Berkeley psychologist and author of "Born to be Good: The Science of a Meaningful Life," and his fellow social scientists are building the case that humans are successful as a species precisely because of our nurturing, altruistic and compassionate traits.

 

They call it "survival of the kindest." <
>

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The benefits of Selflessness can easily be seen through a game theory game called "The Ultimatum Game".

 

It is a simple Game:

 

1) One person (Person A) is given an amount of money.

2) Person A then splits the money into too piles as they see fit.

3) Person A then give one of these Piles to Person B.

4) If person B thinks it is a fair deal, they can accept the money gien and then both Person A and Person B keep the money.

5) If Person B rejects the money, then neither of them get any money.

 

Now, you might at first think that it would always be of benefit to you to accept whatever is given to you as something is better than nothing. And, if you never interact with Person A again, then this is a good solution.

 

But, if you interact regularly with Person A, then it is of benefit to you to reject unfair offers so that in future they will give fair offers if they want to keep the money (actually it could be food or whatever, money is just a good way of expressing "value").

 

Now, if you are in a group with more than just the two people interacting, there now is more of an advantage to rejecting unfair offers, especially if you can be seen to do so. By being seen to reject an unfair offer, it sends a message to other members of the group that you understand the concept of fairness. They can then infer that in dealings with you they can be trust that you will be fair as well.

 

This means that you will have more options for mutual gain than someone who is not fair. Which means that your more likely to be better off (more fit) than the unfair person.

 

Now from here true altruism (giving your life) is but one more step. Groups that have fair, mutually beneficial interactions are more likely to do better than ones that can't trust their own members. This synergy between the group members allows them to do better than a group that doesn't act fairly to each other. And, as members of a group are likely to have very similar genes, then it is in the genes best interests if they occasionally have to sacrifice one of the groups members to gain a benefit for all the rest.

 

If this occurs too often, then it is a hindrance to the group and will be removed from the gene pool, but used occasionally, it can be of great benefit for the rest of the group.

 

Just by looking at this one example (the Ultimatum game) it can show how selflessness can arise. But you have to remember some important things about it:

- Repeated interactions between individuals is an important factor.

- Being able to observe others allows the simple "fair deal" to expand into an effect that goes beyond the interactions to other aspects of the group environment.

- For it to evolve (initially) there needs to be a high degree of similarity between the genes of the individuals of the group.

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Dak - I'm not entirely sure what you're referring to, but I'd suspect that any differences we find are more rationalizations than rational difference. Again, though... I didn't really follow the point.

 

It was in response to Skye's comment on worker-bees.

 

in at least some insects the males are haploid and the females diploid.

 

The implication of this is that, if you consider sisters, the half of their DNA that they inherit from their father will be identical, meaning that sisters are 75% genetically identical to oneanother, but only 50% genetically identical to their offspring.

 

Hence, with insects (unlike humans), the best way of passing their DNA on is to produce more sisters, which can only be done by their mother, so their best reproductive strategy is to protect their mother; as this is true of all of them, it's a small leap to understanding how evolution could lead to a selfless society.

 

None of the above is true of, e.g., humans (or some insects), hence selflessness wrt evolution in some insects will not neccesarily be comparable to selflessness wrt evolution in other insects and non-insects.

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