The evolutionary stable strategy relates to a trait which can
exist and be passed on to the majority of the population. The
strategy is passed on by the survivors of each generation on an
evolutionary time scale. In order to succeed in doing this, the
strategy cannot be bettered and the charcteristics represented by the
strategy must dominate the population. The individual therefore needs
to adopt the strategy to be successful. An evolutionary stable set
of genes is then estblished.
Changes to genes can still occur but this is mainly due to mutation
and these are normally quickly erradicated by natural selection.
When a new gene does succeed in invading and spreading through the
evolutionary stable gene pool, the ESS is altered through the natural
seletion process. This normally occurs in times of environmental
change when the ESS which was previously successful might have
difficulty in adapting to the new environment, resulting in the
reproducing population adopting another ESS so that they can progress
into the next generation. The new ESS will take time to establish
itself as carrying the dominant genes of the population. The
population will continually select itself against the original ESS.
In an artificial environment where environmental change did not
occur, would the gene pool then become smaller with only the optimum
genes being present in future generations? Would this also mean that
the population could become more alike? I imagine that in the long
run this would also make the population more competitive as the
genetic differences between the indiviuals which were competing would
be minimal.
A trait only exists if the vehicle carrying the genes succeeds in
reproducing. According to R Dawkins people who are selfish have more
chance of carrying on their genes as they are able to use all their
energy in ensuring that their genes and their family's genes survive
into the next generation. This differs to alturistic people who use a
lot of their energy in helping non-family members and therefore do
not have enough energy available to ensure the survival of their own
genes. Dawkins therefore suggests that through evolution the selfish
gene has become dominant to the alturistic gene as selfish people are
more likely to reproduce and their genes are more likely to be
carried on to the next generation. This explanation needs to be
elaborated on but I will leave that to after the next seminar.
Sonia Whitehead
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