Re: "The Selfish Gene"

From: Tom Hart (
Date: Sun Oct 19 1997 - 21:24:12 BST

Excuse the lateness of this e-mail, I tried to read as much of the book
before I sent something. So from the book and the seminars it appears
that Dawkins has taken the evolutionary aspects of Darwins theory and
branched off to explain it in terms of the survival of the gene rather
than survival of the species. According to Dawkins it's the ability of
the gene to code a survival machine which can pass on replicators
through asexual or sexual reproduction. Whether or not this is done
depends on how the individual was coded. Survival of the species simply
means that the genes have been successful in their design of a
"carrier" in the present environment. If the environment were to
radically change natural selection dictates that the genes would either
adapt or die out.

The biological aspects of altruism and selfishness are tool with which
Dawkins has used to explain factors of genetic behavioural traits
(inclusive fitness, evolutionarily stable strategies)

I'd just like to pick up on a few of the points in the book
that confused me:

Dawkins looks at the behaviour of baby cuckoos in respect to them
ousting the other species of bird eggs out of their own nest. This is
simply explained in terms of The Selfish Gene. However he goes on to
report that the same behaviour has been observed in the Spanish baby
swallow when one was placed into a magpie's nest, and suggests that
this doesn't have anything to do with the fact that it's a different
species. Rather an attempt to lower the clutch size to increase the
chances of it's genetic survival.

If the chick was one of 5..."he can acquire a 1/4 share simply by
tipping out one egg; a 1/3 share by tipping out another. Translating
into gene language, a gene for fratricide could conceivably spread
through the gene pool".P135

This seems to oppose a lot of what The Selfish Gene says on family
planning and genemanship. Any replicator that coded it's survival
machine to 'take out' their brothers and sisters would greatly reduce
the chance of success of the genes. As your brothers and sisters carry
half of the same genes as you, killing two (in gene terminology) would
be the same as killing yourself. Another possible reason for the
"fratricide gene' not gelling with The selfish Gene theory is the
explanation given for reduction in clutch size. If, due to
environmental constrictions, the mother reduces her no. of offspring to
the optimum size for the best chance of success in rearing them to
reproductive age so they can reproduce , a gene for fratricide would
reduce the clutch size even further . Even though greatly increasing
the chance of survival to adulthood of a few, they would be at a
disadvantage compared to members of the same species who didn't contain
the 'fratricide gene' at birth, and so that trait would be selected out
through evolution.

It seem that in order for the parent's gene to win or even compete in
"the battle of the generations' in a species with the fratricide gene,
the parents best defense would be to contain a gene that coded for many
offspring at one time to give them a chance of ending up with the
optimum clutch size.

Explanations for apparently altruistic behaviour in species was
mentioned early in the book and again in chapter 10 (Particularly in
"social insects' p172). Dawkins spends a lot of time suggesting
"Selfish Gene' reasons for the behaviour of these Hymenoptera Insects
(which confused me after a while).

Partly because of the following; Within these nests there a specialised
castes of workers, soldiers, drones e.t.c.(and usually one mature
queen). I imagine that the ratio of these different types is an ess, so
that the overall productivity of the group optimises the success of the
gene.( e.g. there are enough (infertile) workers to cater for the
successful reproduction of others and the queen. I understand that the
apparently altruistic behaviour of the infertile workers is actually
them working for the good of their genes in their kin. What confused
me seems to be a basic principle in The Selfish Gene. Namely offspring
contain a ratio of father/mother genes which seems to be able to vary
in these Hymenoptera Insects.

If this is therefore true then how does a gene for producing sterile
workers spread through the population. It seems that even if the entire
population at one time were reproductive and genetic variation produced
a sterile member who just worked for the good of others (or the genes
of other's and therefore their own),and this was successful, there
would be no way to pass on the trait to another generation. However,
this isn't the case and there are these types of workers within
Hymenopteran insects. It may have been explained by Dawkins and I
missed it.

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