The Selfish Gene is about the biology of selfishness and
altruism with respect to Darwin's theory of Natural Selection.
In the beginning, there was a primordial soup of individual
atoms, some of which were more stable in the environment than others. By
definition, the stable ones continued to exist while the unstable ones
died out. When these early proteins began to react to environmental
conditions so as to form compounds, they began also to change their
function in the environment to complementing or hindering other proteins'
existences. With replication, it became possible to pass on successful
traits (or genes) to successive generations and thus evolution began.
As proteins grew and congregated with others, they began to
build houses for themselves, or protective shells, or survival machines.
Survival machines became increasinly elaborate as more and more genes
worked together to enhance the body's chance for survival and
replication and to attack neighbours who might act to restrict those
chances. The reason survival machines did not become infinitely huge is
because of the constraints placed upon development - namely
environmental conditions.
Genes would congregate in one organism/survival machine and
would have to combined effect of making that organism more likely to
replicate given that environment. The genes themselves are not
altruistic, since they "want" to survive into the next generation. Of
course, they don't plan to act in a certain way, but across a random
variation in genotypes (and phenotypes) some will do better in that
environment, on average, than others. They survive, selfishly, at the
expense of other genes.
Individual genes may die out by accidents, no matter how well adapted
they are, but on average 'good' genes survive. Dawkin's analogy of
selecting a rowing team from many rowers - individuals randomised into
teams for each race and selected on the basis of finishing in the
winning team the most times. A bad rower may luckily always be placed in
a team with good ones, thus ensuring his place in the final team.
The care/bear decision. A person is equally related to their
younger sibling as to their own child (50% above the baseline for the
species) so do they choose to care for an existing child or to bear a
new one? Altruism dictates a Caring strategy, but clearly that is not an
ESS. Likewise, a Bear strategy, is likely to have a high infant death
rate.
Altruistic birth control is likely, as it can be seen that
despite cyclic variations in the population rates of animals, the mean
population is stable over time. The gathering of gulls at a place each
year gives a rough estimate, to an individual gull of the total number.
If there are many already, the environment is such that a large clutch
size would result in relatively few of the children surviving and effort
having been wasted. Too small a clutch size would mean that more
children could have survived and the individual did not take advantage
of those conditions. Consequently, genes for having too few children
would die out.
Genes do not consciously want to survive. Genes are not really
quantifiable units but are above the level of atoms and below
personality or physical traits. They vary across a range, and it is
according to the environment which ones survive to replicate.
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