Evolution

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Evolution

• Changes in a population, a species, or a group of
  species over time.

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What is Evolution?

• A change in the gene pool of a population in
  response to various stimuli exhibited by a
  species over time.

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Why the geology in biology class?

• Fossils are so key in studying change in traits
  or alleles

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Involved Geologist Theories

• Hutton 1795
• Uniformitarianism- processes today are the same
  as the past
• Cuvier 1815
• Catastrophism because of extinction evidence
• Lyell 1830
• Used Huttons ideas concluded VAST amounts of
  time in geologic history

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Rock layers strata
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Fossils tell us

• Different organisms appeared at different times
  and places
• Relative ages of rocks
• Some organisms appear to have disappeared or gone
  extinct

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Law of Superposition

• The lowest rock strata are the oldest!

Which is the oldest organism? A or D??
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• Biologist theories
• Jean Baptist Larmark
• Theory of Inheritance of Acquired Characteristics
  - 1801
• Change is made by what
• the organisms want or need
• and then is passed down
• to offspring.
• WRONG !!!
• Why? think about tattoos

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Charles Darwin -1809-1882

• Great observer and naturalist
• Age 22- sailed H.M.S. Beagle to South America
  Galapagos Islands.
• Wrote The Origin of Species (described decent
  with modification)
• Major findings Coral fossils
• at top of mountains, similarities
• among Oceanic Island species.

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The Voyage that Changed Everything
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Galapagos finches
Sp. From an island with cactus for food
Sp. From an island with seeds for food
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• The finches of the Galapagos Islands diversified
  after an initial colonization from the mainland
  to exploit different food sources on different
  islands.

Idea behind decent with modification!
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• The Origin of the Species convinced most
  biologists that species are the products of
  evolution, but acceptance of natural selection as
  the main mechanism of change was more difficult.
• What was missing in Darwins explanation was an
  understanding of inheritance to explain how
  chance variations arise in a population while
  also accounting for the precise transmission of
  these variations from parents to offspring.
• Although Gregor Mendel and Charles Darwin were
  contemporaries, Mendels discoveries were
  unappreciated at the time, even though his
  principles of heredity would have given
  credibility to natural selection
• No knowledge of genes until later

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Biological diversity is something to relish and
preserve, but it can also be a bit overwhelming.