[extropy-chat] Reverse Evolution ?
mbb386 at main.nc.us
Thu Mar 2 01:00:35 UTC 2006
> mission, should you decide to accept it, is to explain evolutionary theory
> to the layman using the amount of text that would fit on one side of one
> sheet of printer paper, using language not out of reach of the average
> eighth grader. Ready set go.
The currently-accepted scientific model of evolution was first laid
out in Darwin's book On The Origin of Species Through Natural
Selection. The Darwinian theory of evolution can be summed up in a
number of simple postulates:
(1) The members of any particular biological population will differ
from each other in minor ways, and will have slightly differing
characteristics of construction and behavior. This is the principle
(2) These variations can be passed from one generation to the next,
and the offspring of those possessing a particular type of variation
will also tend to have that same variation. This is the principle of
(3) Certain of these variations will give their possessor an
advantage in life (or avoid some disadvantage), allowing that
organism to obtain more food, escape predators more efficiently, etc.
Thus, those organisms that possess such a useful variation will tend
to survive longer and produce more offspring than other members of
that population. These offspring, through the principle of
heritability, will also tend to possess this advantageous variation,
and this will have the affect of increasing, over a number of
generations, the proportion of organisms in the population which
possess this variation. This is the principle of "natural selection".
These principles are combined to form the core of the evolutionary
model. The Darwinian outlook holds that small incremental changes in
structure and behavior, brought about by the natural selection of
variations, produce, after a long period of time, organisms that
differ so greatly from their ancestors that they are no longer the
same organism, and must be classified as a separate species. This
process of speciation, repeated over the 3.5 billion year span of
time since life first appeared on earth, explains the gradual
production of all of life's diversity.
(by Lenny Flank, as presented to middle-school kids, used with permission)
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