Redefining Reality - The Intellectual Implications of Modern Science

If you select strange enough traits, breed only those with that
set of traits, and separate them from the original population,
you will eventually develop a group of organisms that bear
little resemblance to the others. In isolated areas, where
physical and geographical boundaries prevent interbreeding,
the result will be groups of organisms that are quite unlike each
change that a completely new species emerges.
The third principle—you must be alive to have children—is
the well-known doctrine of natural selection. It begins with the
presupposition that the world is a dangerous place, in which the
stuff you need to survive is limited in quantity and you are the stuff
some other animals need to survive.
Darwin was familiar with the work of Thomas Malthus, a
clergyman and social theorist who had written An Essay
. According to Malthus,
human resources are growing linearly, while population is
growing exponentially. Eventually, this will result in intense
competition for the limited goods needed for survival and a
crash in population due to mass starvation.
world. There is constant competition for scarce resources
within a species and danger from others. If an organism is to be
successful in passing on its traits, it needs to procreate and for
this, it needs to survive.
The random mutations that pop up will most likely not be a
help to survival; indeed, most are a detriment. As a result,
will disappear from the population. But in the rare case that
the mutation conveys a positive trait, an aid in surviving,
there is a greater likelihood that the organism will procreate
and, therefore, a higher probability that the trait will not only
continue but increase its appearance in the population.
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