The Blind Watchmaker

From: Dunn Christopher (
Date: Thu May 23 1996 - 15:48:56 BST

Question 17 What is the "Blind Watchmaker"

The "Blind Watchmaker" is a metaphor for evolution insofar as the
process of evolution and natural selection are "Blind" .Members of a
species which possess a characteristic which increases their chance of
survival over other members who do not possess this characteristic will
have a better chance of surviving and passing on there genotype (their
genetic code including the characteristic which aided their survival )
to the next generation .This process is blind because it is random
depending on a combination of many variables, including the
environmental changes in temperature ,availability of food , predators
to prey ratio ,shifting land masses and countless other factors .

If members have a characteristic which enables them to adapt to changes
in the environment successfully then they will survive and the gene
that helped them survive will become dominant in successive generations
, just as members who could not adapt due to their genotype will die
without passing on there genotype . An example of the random factors of
evolution can be seen in the case of the peppered moth which was a
speckled white color as this characteristic camouflaged it as it rested
on the bark of trees . During the industrial revolution a mutant form
emerged which was much darker, and the white form of the moth began to
declined .The reason for this decline and the dominance of the mutant
form was smoke and soot from the many new factories darkened the bark
of the trees ,making the previously camouflaged white moths stand out
and easily predated by birds and the darker moths camouflaged against
the darker bark thus much harder to spot by birds .So by changes in
the environment the darker moths possessed a characteristic which
enabled them to adapt and survive in the new environment. This is the
"Blind Watchmaker" or evolution at work.

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