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| Charles Darwin |
Consider the following paragraph by Darwin in The descent of man (chapter 5):
With savages, the weak in body or
mind are soon eliminated; and those that survive commonly exhibit a vigorous
state of health. We
civilised men, on the other hand, do our utmost to check the process of
elimination; we build asylums for the imbecile, the maimed, and the sick; we
institute poor-laws; and our medical men exert their utmost skill to save the
life of every one to the last moment. There is reason to believe that
vaccination has preserved thousands, who from a weak constitution would
formerly have succumbed to small-pox. Thus the weak members of civilised
societies propagate their kind. No one who has attended to the breeding of
domestic animals will doubt that this must be highly injurious to the race of
man.
It seems incredible that, after a lifetime
devoted almost exclusively to meditate on his theory of evolution, Darwin made
the mistake of applying it wrongly to humans, as is clearly demonstrated in the
paragraph I have just quoted.
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| Jacques Monod |
Biological
evolution is the result of the complex interaction of four factors:
1.
The
genetic variability of organisms, which in turn is the result of the
interaction of their genes with a huge set of external and internal factors:
natural or artificial radiation, chemical substances, gene shuffling by sexual
reproduction, etc. These factors are often unpredictable or unknown, therefore
they are usually considered the result of chance.
2.
The
environment, also subject to variations that, in the whole, can be considered
random.
3.
Natural
selection, which is essentially the observation that individuals better adapted
to their environment are more likely to leave offspring. Despite its
probabilistic nature, this factor of evolution is often considered virtually
deterministic. In Jacques Monod’s formulation [1], it represents necessity.
4.
The
basic rules of the game (the physical laws governing the universe). Depending on
what laws we are talking about, this component can be considered part of chance
(quantum mechanics) or of necessity (general relativity).
According to Darwin's theory, a biological
species may be well adapted to its environment, but if the latter changes (we
have seen that those changes can be random), such adaptation may be lost, in
which case the species in question could suddenly become maladjusted, and even
extinct.
Many years ago I wrote these two paragraphs in
a popular science book [2]:
Advances in medical science have
made it possible that many human beings (those whom heredity or genetic
variability has provided with deleterious genes, leading to disease or to physical
weakness) do not die in childhood, as happened before, but reach maturity and
leave offspring, thus perpetuating their "harmful" genes, which
gradually spread to an increasing number of individuals. Some people wonder if
future mankind will have so many genetic defects in its normal complement that
humans will only be able to stay alive artificially, relying entirely on the
means of medicine.
It is questionable whether this
situation is really worrying. All that this means is just that man has adapted
to a different self-made environment. Genes that would have been lethal in
other conditions, in the new circumstances are indifferent or even beneficial.
The laws of evolution and natural selection are still operating. Only the environment
has changed.
Darwin's mistake was believing that natural
selection acts independently of the environment. How else could he think that
the same genetic characteristics that made savages
adaptable to their environment should remain favorable when applied to civilized societies? That the weak
can now survive and are able to reproduce only means that these individuals are
now well adapted to their environment.
A very different question is what would happen
if a natural or provoked catastrophe made it impossible to maintain our
artificial environment. Would the human species become extinct? It is possible,
but in that case it would be due, as in many other cases of extinction, to a
simple change of environment. But that is another story.
[1] Jacques
Monod, Le hasard et la nécessité,
1970. Chance and necessity, 1971.
[2] Manuel Alfonseca, La vida en otros mundos, Alhambra, 1982; MacGraw Hill, 1993.
Manuel Alfonseca
This is a great quote you pulled out from Darwin's work. Many republicans may use it as a "scientific" argument to eliminate any healthcare whatsoever. As far as the theory of evolution though, applied to humans, the first 10 minutes of movie "Idiocracy" is spot-on. In that respect, I disagree with your item 3. unless by "individuals better adapted to their environment" you mean those who procreate fastest... ;)
ReplyDeleteMS
Darwin's theory of evolution was used (wrongly) by most ideologies based on the supremacy of whatever group: the Aryans (as in Nazi Germany), the proletariat (as in Marxism), or in the philosophy of Nietzsche and those who believed in the nearness of "superman" (as the Fabians in the U.K. at the beginning of the 20th century).
Delete"Individuals better adapted to their environment" does not necessarily mean those who procreate fastest. The environment sometimes favours those who procreate more slowly. Faster procreation is usually selected for in small animals, slower procreation in larger (including us and elephants, for instance).