Transcript The Theory of Evolution

The Theory of Evolution
A Modern Criticism to the Design
Argument (NOT to the First Cause
Argument)
Evolutionary Theory
•
•
•
•
•
The word ‘evolution’ means ‘gradual
development’
Evolutionary ideas have been present
(although not widely known) throughout
history.
It was not until the observations of Charles
Darwin (19th C) that a scientific theory of
evolution began to emerge.
Darwin’s original theory was written in his
Origin of Species in 1859.
Therefore, there was no theory of evolution at
Hume / Paley’s time.
The Science of Evolution - Darwinism
1. Charles Darwin studied biology and
geology, and was also interested in the
works of William Paley!
2. On a 5 year voyage that took him to the
Galapagos Islands he began to wonder
why God would have bothered making
different species for each different island.
3. He began to think that there was no ‘fixity
of species’, but that they might instead
be developing from a finite number of
‘original’ species.
4. On return home, Darwin began working on his
new theory and was influenced by several
writers (see p.46)
5. He liked the idea in Malthus of every being
‘fighting for survival’ where only the strongest
survive. This led to the idea we now know of
as natural selection (Darwin likened this to
artificial selection in animal breeders).
6. Darwin believed if the natural variation in
generations (longer legs, etc) were the traits to
‘win’ and develop, then over millions of years
there could be a completely different group of
animals / species from the original.
7. He later, in Descent of Man applied this
controversial theory to humans.
Summary of Darwinism
1. Life originates from a primeval ‘soup’ 3,5004,000 million years ago.
2. Initial species developed with the fittest
surviving.
3. Competition amongst species lead to the fittest
offspring surviving (there are always more
babies than the environment can support – they
compete for resources to survive and best
adapted wins!)
4. No single act of creation needed for each
species.
5. Humans are different by ‘degree’ not kind.
Neo-Darwinism
• This is the type of evolutionary theory we have today. It is
based on the original ideas of Darwin, but revised with more
scientific evidence.
• Darwin’s original theory did not account for emergent
species, just adaptation to environments.
• Gregor Mendel came up with a mathematical formula that
became the basis for evolutionary biology.
• Then, Francis Crick and James Watson worked out the
structure of DNA, and how genes are passed on through
generations – half DNA from each parent to make NEW
COMBINATIONS.
• This natural variety, and random mutations (when something
‘goes wrong’ in someone’s genes and leads to disability or
an advantage), make up the changes we see in species over
long periods of time. The best changes survive.
• Life itself started with the first molecule of DNA, although
scientists do not know how atoms managed to form living
cells, and developed through mutations.
We now ‘know’ that:
1.
2.
3.
4.
5.
Life probably started 4000 million years ago, although
2000 million years of this would have been mostly
bacteria.
1000 million years ago, simple multi-celled (visible) life
would have appeared, with plants and animals soon to
follow.
Variation in life is caused by gene mutations. These
survive if they allow best adaptation to environment.
This process of change happens over many
generations.
Evolution by natural selection therefore rules out the
need for God.