Darwin and Hamilton



To S.B.E. Readers:

It is "clear to me" at least kin selection and biological altruism is
indirectly tied to genocide. Perhaps to some evolutionary biologists
this is obvious and mentioning it produces a "big yawn". However, it is
nevertheless morally reprehensible. Although human beings are generally
genetically identical apparently accumulated genetic drift along with
influences of native language and culture are enough to potentially
send the wheels of genocide spinning. Kin selection and biological
altruism could operate in a number of ways. A signifigant influx of
migrants or legal migrant citizens who have increasingly occupied
positions of power and influence in all spheres of society could
provide an impetus for kin selection and biological altruism. I don't
accept that merely culture/religion alone is totally responsible for
genocides. Even in the case of the Khmer Rogue there was a form of kin
selection/altruism against their own people. The intelligentsia, those
who wore glasses, etc.

I understand kin selection and group selection are somewhat different.
So the question is (a) Can kin selection/group selection under the
right circumstances lead to genocide? (b) Is genocide possible without
kin selection/group selection (c) how is culture/religion tied up with
kin selection/group selection (d) is kin selection/group selection
still necessary in our evolution. Is it adaptive?

It seems to me from a Darwinian view it is individual organisms
struggling to survive whereas in kin selection/group selection it is
groups formed into certain geographic areas, accumulated genetic drift,
culture/religion which struggle to survive.

Needless to say I have no use for either Darwinian natural selection or
Hamilton's kin selection. Hamilton may have based his kin selection on
eusocial insects but it has been extrapolated to humans.

Note to Moderator: I'm asking legitimate questions. I'm not Nuenke.
Please allow to overide political correctness. The more it is not
discussed the more it festers.



A key contribution to sociobiology was made by an Englishman, William
Hamilton. He would repair from his depressing graduate-student digs
to the relative comforts of Waterloo railway station, and there was
rewarded with a monumental insight. Darwin's theory of evolution had
implied that natural selection would generate a selfish world. It was
"the fittest" that survived, after all, and that presumably meant
looking out for No. 1. Yet, undeniably, there was a lot of altruistic
behavior out there. Darwin himself had viewed with alarm the elaborate
cooperation of the social insects. Hamilton's explanation, published
in 1964, took time to sink in, but once it did, the evolutionists sang
his praises and have continued to do so without end. Kin selection-of
course!

A gene exists not just in one organism, Hamilton argued, but also in
others, closely related. Siblings share half their genes, first cousins
share one-eighth of theirs, and so on. (These ratios were arrived at
not by comparing the actual DNA of individuals, but as a deduction from
the postulates of Mendelian genetics.) Consequently, Hamilton argued,
an action that endangers the individual but promotes the survival of
more than two siblings, or more than eight first cousins, would
nonetheless be advantageous: it would promote the spread of the gene
that triggered the behavior which otherwise seemed so ill-advised.

Hamilton's argument became the backbone of Richard Dawkins' book
The Selfish Gene, and it was a lifesaver for Wilson. The Darwinian
scheme had been preserved intact. It had given away nothing by taking a
more "inclusive" view of fitness. Then Robert Trivers expanded the
analysis to more distantly related animals, positing genes for
"reciprocal altruism." That was judged to be less successful, but
with the costs and benefits appropriately assigned, it could be
invested with an air of plausibility.

The kin selection theory, published in the Journal of Theoretical
Biology, was expressed in obscure mathematics, but that was one of its
triumphs. It all seemed so precise, so up to date, and yet so
mystifying to the hoi polloi. Nature had rejected it! Hamilton was
rapidly promoted from his waiting-room outpost. And when he died of
malaria in the course of a research expedition to Africa last year, his
funeral oration in the chapel of New College, Oxford, was not just
delivered by the atheist Richard Dawkins, but reprinted by the Times
Literary Supplement. Tom Wolfe didn't quite get it right, apparently.
Not E. O. Wilson, but William D. Hamilton was truly Darwin II. "Those
of us who wish we had met Charles Darwin can console ourselves,"
Dawkins began his eulogy. "We met W. D. Hamilton."





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Altruism - a puzzle for natural selection

The phrases 'Survival of the fittest' and 'Nature, red in tooth and
claw' are associated with Darwin's theory of evolution through natural
selection . They portray a world populated by selfish organisms intent
on their own survival. This lecture examines the paradox of altruism.

Why do we co-operate with one another?
Why do humans and other animals make self-sacrifices that benefit other
members of their species?
For example:

Why do bees sting?
Why do animals emit alarm calls that reveal their presence to
predators?
Why are some poisonous insects brightly coloured?
These are examples of altruism or self-sacrifice. The existence of
altruism posed a significant challenge to Darwin's theory of evolution
through natural selection. Recent evidence has highlighted the
importance of co-operation to evolution. It turns out that an answer to
the altruism-paradox may involve paying more attention to 'selfish
genes' rather than selfish people.


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Hamilton's kin selection theory

Kin share many common genes. Genes can spread by benefiting other
carriers of the same gene. Hamilton proposed the inclusive fitness or
kin selection theory to explain altruism or self-sacrifice.

In an altruistic encounter there is:

an altruist or donor who bears a cost ( c )
a recipient who gets a benefit ( b )
a degree of genetic relationship between the donor and recipient
The probability that the altruist and the recipient share a gene is
called the coefficient of relatedness ( r ). The diagram shows the
extent to which we share genes with our relatives. The value of r
varies between 0 and 1. On average we share half of our genes with our
brothers, sisters and children ( r=0.5 ), and a quarter of our genes
are identical with those of our grandchildren, nephews and nieces (
r=0.25 )

According to Hamilton's Rule altruism pays off if rb>c . In other
words, shared genes will profit if the cost to the altruist is less
than the benefit to the recipient multiplied by the probability that
the recipient shares genes with the donor.

Costs and benefits are expressed in units of fitness or reproductive
success with values between 0 and 1.

A cost of 1 unit of fitness means that the act would reduce the donor's
reproductive success by 1 offspring.
A benefit of 1 unit of fitness means that the recipient would increase
their reproductive success by 1 offspring.
For the sake of argument assume you have spare food that you could give
to your brother to feed him and his children.

Assume that the cost to you is 0.1 units of fitness (i.e. if you do
this 10 times you will have one less child)
Assume that the benefit to your brother is 0.25 (i.e. if he receives 4
such donations he will have one more child)
We can test if your altruism would benefit kin selection by putting
these values into Hamilton's Rule rb>c where:

r ( the coefficient of relatedness between you and your brother) = 0.5
c (the impact on your reproductive success ) = 0.1
b ( the benefit to your brother's reproductive success) = 0.25
rb =0.5x0.25=0.125
c=0.1
because rb>c (0.125 is greater than 0.1) Hamilton's Rule is satisfied
and your altruism would benefit your genes
You might wonder why b and c are not always equal. Why not use the
spare food you have to increase your own reproductive success? Well
there is a limit to how much you can eat. If you have an abundance of
food and your brother is starving, the cost to you of sharing is small,
but it may be a matter of life or death to your brother and his
children.


.

Relevant Pages

  • Re: Logic of kin selection
    ... General kin selection models for genetic evolution of ... sib altruism in diploid and haplodiploid species. ... Theoretical Population Biology ... Kin selection: a classical approach and a general ...
    (sci.bio.evolution)
  • Re: Hamiltons rule
    ... This is an interesting inversion of the way kin selection is usually treated ... think) than Trivers' model of reciprocal altruism, ... Contexts in which this can ... > even aware that an act of generosity occurred; ...
    (sci.bio.evolution)
  • Re: Perpetually Perplexed
    ... >> If the organism's altruism is expressed to a particular degree in all social ... >> interactions, ... >> not the assumption in most of the empirical kin selection literature. ... can save the mean field approximate model, ...
    (sci.bio.evolution)
  • Hamiltons Rule invalid?
    ... Hamilton's rule, and the model of kin selection on which it is based, was ... on the gene, ... The concept of inclusive fitness ... of a gene for altruism but only if fairly extreme conditions are met. ...
    (sci.bio.evolution)
  • Re: Hamiltons Rule: light at the end of a LONG tunnel?
    ... >>> I think you are confounding Hamilton's kin selection model with Trivers' ... >>> reciprocal altruism model. ... >>> certainly further facilitate an increase in the altruism allele through the ... >>> mechanism of reciprocal altruism, is also not accounted for in the precise ...
    (sci.bio.evolution)