Sociobiological Concepts

From: Jon Wright (
Date: Wed Oct 01 1997 - 11:15:05 BST

In the session on Tuesday 31-9, we went over a few definitions and
concepts to be covered in the course.

What is evolution? Evolution is a process of progressive devlopment such that
organisms which prosper in a given environment, continue to flourish while
the less well-suited organisms die out. It need not be an organism which
evolves but also an ontogenic behaviour considered `successful' by others of
the species. Survivors survive, while the weaker (=less well adapted) die out.

The process of Natural Selection occurs through the natural variation
within members of a species, such that the better survivors have more chance
of reproducing and passing on their characteristics to the next generation.
Success can be measured in terms of how long a lineage a particular gene/
trait stretches. Cloning is a succesful form of reproduction as long as the
parent is well adapted to the prevailing environment but sexual reproduction
enjoys an advantage over asexual reproduction in the case of subtly varying
conditions, since genes of two individuals are combined to create a unique
new individual which may turn out to be more succesful in its environment and
consequently pass on better qualities to the next generation.

Significant variation in the make-up of a species may take 100's of
generations so the current traits and tendencies should only be interpreted in
terms of the Environment of Evolutionary Adaptiveness (EEA) or the Original
Environment. These concern the `distal' causes of evolution.

An ESS is a trait which can exist and prosper and not be invaded by
cheats. If a person helped any stranger they met, then there would be a `help
debt'. If the rule was that you would try to help strangers in order that they
they would help you (to pay off the debt) then it would result in a net
population of helpful people. Cheats could not simply expect help as they have
to earn it. Individuals would try to stay `out of debt' and help as many
others as they could.

As for the Modus Ponens (sp?) I was a bit confused. Swans are white - Y.
This is a swan - Y. Ok. This is white - N. ???

Jon Wright - jjw195

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