The Theory of Evolution

1
The Theory of Evolution

• A Modern Criticism to the Design Argument (NOT to
  the First Cause Argument)

2
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.
• Darwins original theory was written in his
  Origin of Species in 1859.
• Therefore, there was no theory of evolution at
  Hume / Paleys time.

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The Science of Evolution - Darwinism

• Charles Darwin studied biology and geology, and
  was also interested in the works of William
  Paley!
• 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.
• 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.

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• On return home, Darwin began working on his new
  theory and was influenced by several writers (see
  p.46)
• 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).
• 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.
• He later, in Descent of Man applied this
  controversial theory to humans.

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Summary of Darwinism

• Life originates from a primeval soup
  3,500-4,000 million years ago.
• Initial species developed with the fittest
  surviving.
• 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!)
• No single act of creation needed for each
  species.
• Humans are different by degree not kind.

6
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.
• Darwins 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 someones 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.

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• We now know that
• 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.