Re: Sociobiological Concepts

From: Rebecca Dale (
Date: Mon Oct 06 1997 - 15:09:37 BST

In the first seminar of sociobiology the process of
evolution was defined and discussed.

Evolution is a blind causal process in which genes or blueprints for
certain traits can either aid or hinder an organism in its present
environment, either allowing the organism to survive and reproduce or
to die. These traits are then passed on to the next generation. A gene
is said to be successful if it codes for a trait that enables an
organism to survive and reproduce. For example, a gene that coded for a
liking of sugar would lead the organism to eat sugar, in turn supplying
more energy, which then enables an organism to fight, which in turn
leads to longer survival, which then leads to more reproduction: thus
being passed on to the next generation, SUCCESS!

Sexual reproduction is more advantageous than asexual reproduction, in
that it provides more variation. An individual is created by the genes
of two parents and so may be more successful. Cloning is successful
only if the parent was well adapted to the present environment.

The Environment of Evolutionary Adaptiveness (EEA) is the original
environment, ultimately where the distal causes can be found. For
example, in the EEA, sugar was needed for survival. Organisms that
carried a gene for liking of sugar survived. The proximal cause for
sugar preference is that it tastes good.

An Evolutionary Stable Strategy is a srategy which, if most members of
a population adopt it, it cannot be bettered by an alternative
strategy. (Dawkins!) I am not very sure on this concept but will try to
give an example.

Suppose a male bird fertalises a female and chooses a nest. Whilst the
male must then provide food for the new born chicks, to maximise his
genetic output, he fertalises another female (secondary female) who has
already nested with another male close by (obviously while the male is
out of sight). This strategy has several advantages: the two nests are
close by so he can feed both easily; if one batch dies, he has secured
his genetic output, if he did fertalise the secondary female, her mate
may unknowingly provide food for her new born chicks. Male birds which
choose just one mate will not be as successful because they may be
finding food for someone elses chick! (this example is just a wild stab
in the dark!!)

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