Download Lecture 8, Evolution

The Place of Homo sapiens in
Nature
Evolution
Charles Darwin (1809-1882)
Developed the theory of evolution while
traveling on the Beagle in the Galapagos Islands.
In 1859 published: On the Origin of Species by Means of Natural
Selection, or The Preservation of Favoured Races in the Struggle for
Life (usually referred to as “The Origin of Species”)
Descent with variation, survival of the fittest
The individuals most well-adapted to their
environment survive and leave the most descendants.
The survival of those that survive.
C19th anti-Darwin cartoon
The place of Homo sapiens in nature
Entirely new way to view the relation between people and nature
People are animals.
Intelligence (like eyes, wings, etc.) evolved naturally and for no reason (i.e.
nature has no foresight)
An naturalistic solution to the watchmaker problem
• The Blind Watchmaker, Richard Dawkins (1986)
Materialistic: not dualistic, no supernatural explanation:
• God? “I have no need of that hypothesis” – Laplace (early C19th)
Common misconceptions
Evolution is sometimes identified with the great chain of being,
hence:
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Evolution represents progress.
Evolution can be represented as a tree or ladder of life,
and humans are at the top.
Man is the most “evolved” animal, hence newest, most
intelligent and most successful.
Further evolution of humans would lead to more
intelligent and better people.
Why these are misconceptions
Evolution is better represented as a bush or ever-expanding pool than
a ladder or tree.
The most successful organisms ever
in evolutionary terms (i.e. occupying
the largest amount of biomass on
earth) are bacteria, and have been
since their development on earth.
Evolution can cause change in the direction of more complex to less
complex and more intelligent to less intelligent, e.g. viruses, sloths.
Increasing complexity does not imply increasing intelligence.
Environmental Implications
We are animals. We are natural products of evolution. But are we special? We
are unique among animals in our intelligence, creativity and capacity for
destruction. This may give us a special responsibility towards the rest of
nature. Or it may just give us reason to be careful (out of self interest) –
not to destroy our home.
Nature is neither good nor bad: it just is.
We are part of nature, and, in one sense, it is impossible for us to go against
nature (like the Great Tao – we cannot go against the laws of nature).
But, in another sense, we can go against our nature or live unnaturally (c.f.
the human dao), i.e. live in a way that is contrary to the environment or
way of life that we evolved to be adapted to. E.g. we evolved to live in
small tribal groups, thus living in sprawling cities is relatively unnatural for
us (hence the high rate of mental illness in modern people?)
Environmental Implications (cont.)
If there is no purpose in nature, the natural way isn’t necessarily the better
way.
So, going against nature (i.e. changing nature or our relationship to nature),
isn’t necessarily bad. It may be an improvement.
But: the natural way is the way that we have evolved to be adapted to, e.g. it
is natural for us to eat a highly vegetarian, low fat, low sugar diet. If we eat
“unnaturally”, e.g. candy and chips, we will not be healthy, because we are
not adapted by evolution to live on such a diet.
Also, if we interfere with nature (e.g. through genetic engineering or global
warming), we may not be able to adapt to the changes that will result.
Nature is a complex interactive system. Small changes may lead to large
changes, and we do not know enough about the biosystem as a whole to
predict the results of changing conditions. We may accidentally cause
drastic changes that we cannot control and cannot adjust to.
The Roots of Morality
Richard Dawkins (b. 1941)
British biologist
The Selfish Gene (1976)
The God Delusion (2006)
An evolutionary account of morality
How did altruism evolve?
1) Altruism towards kin
2) Reciprocal altruism
-- symbiosis
-- mutualism
-- reputation
3) Advertisement of superiority
Why are we still altruistic even when it
doesn’t benefit our genes?
Misfiring of instinct
cf sexual instinct
Dawkins: doesn’t devalue altruism
“[a] blessed precious mistake…”
Our values are independent of the welfare of our genes,
even if they owe their origin to that mechanism
Readings for next week
Required:
Des Jardins, Environmental Ethics (2001),
Chapter 2, on reserve in the Main Library