Darwins Theory of Evolution

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Darwins Theory of Evolution

• Chapter 15

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Puzzle of Lifes Diversity

• The different sizes, shapes and habitats of
  organisms is called biodiversity.
• The evolution theory is a collection of
  scientific facts, observations hypotheses
• Evolution a change over time has alter organisms
  in the past to the diversity of today.
• Theory well-supported, testable explanation of
  natural phenomena.

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Voyage of the HMS Beagle

• Charles Darwin is the father of Evolution.
• Born in England on 2-12-1809
• Naturalists on the HMS Beagle in 1831
• Darwin collected numerous observations and
  evidence to create his hypothesis.
• Darwins hypothesis has been supported by huge
  quantities of evidence and is a theory.

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 Darwins Voyage
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Darwins Observations

• Darwin noticed patterns in the diversity of the
  animals. Similar habitats had different
  organisms in them.
• Fossils collected often looked similar to
  existing species others were different.
• Galapagos Islands provided the most information
  for diversity and climate.
• Isolation on an island could lead to change over
  time in a species.

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Giant Tortoises of the Galápagos Islands
Pinta
Tower
Marchena
Pinta IslandIntermediate shell
James
Fernandina
Santa Cruz
Isabela
Santa Fe
Hood Island Saddle-backed shell
Floreana
Hood
Isabela Island Dome-shaped shell
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Darwins Experience

• James Hutton stated the Earth changes slowly over
  time by natural processes.
• Charles Lyell wrote Principles of Geology which
  stressed explaining the world in observable
  processes.
• Thomas Malthus described human population growth
  over population.
• All of these ideas went against the established
  dogma.

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Movement of Earths Crust
Sea level
Sea level
Sedimentary rocks form in horizontal layers.
When part of Earths crust is compressed, a bend
in a rock forms, tilting the rock layers.
As the surface erodes due to water, wind, waves,
or glaciers, the older rock surface is exposed.
New sediment is then deposited above the exposed
older rock surface.
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Lamarcks Evolution

• Jean-Baptiste Lamarck first realized living
  things change and adapt to their environment.
• Lemarck said that organisms have an innate desire
  to be complex and perfect.
• Lemarck proposed use and disuse lead to acquired
  traits which may be passed to offspring.
• Lemarcks hypothesis has been proven incorrect.

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Lamarcks Theory of Evolution
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Darwins Evolution

• Darwin published his work in 1859 after Alfred
  Wallace wrote similar papers.
• Darwin stated that inherited variation and
  artificial selection caused differences in a
  species.
• Struggle for Existence results in each member of
  a species competing for resources.

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Survival of the Fittest

• Fitness is the ability to survive and reproduce
  in ones environment.
• Adaptation is an inherited trait which increases
  fitness.
• Survival of the fittest means the best suited to
  an environment survive to reproduce similar
  offspring.
• Natural Selection is survival of the fittest.
• Over time Natural selection may alter a species.
• Descent with Modification cause a species to
  gradually change from its ancestor species.

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Evidence of Evolution

• The fossil record, geographical distribution,
  homologous structures, and embryology are all
  evidences for evolution.
• Fossils have shown intermediate species.
• Organisms living in different areas with similar
  environmental pressures evolved similar anatomies
  and behaviors
• Homologous structures develop differently but
  have the same embryonic tissues. Vestigial organs
  exists but serve no purpose.
• Embryos look similar during different stages of
  deveolpment.

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Embryology
dog
human
skink
zebrafish
chicken
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Evidence of Evolution
Evidence of Evolution
includes
which is composed of
which indicates
which implies
which implies
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Beaver
Beaver
Muskrat
NORTH AMERICA
Muskrat
Beaver and Muskrat
Coypu
Capybara
SOUTH AMERICA
Capybara
Coypu and Capybara
Coypu
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 Homologous Body Structures
Turtle
Alligator
Bird
Mammal
Ancient lobe-finned fish
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Summary of Darwin

• Individual organisms differ and some of this
  variation is heritable.
• Organisms produce more offspring than can
  survive, those that do not survive do not
  reproduce.
• Competition is created by producing more
  offspring than can survive.
• Organisms best suited for their environment
  survive to pass on their traits.
• Species alive today descended with modification
  from species in the distant past.
• Evolution is a theory and changes as new research
  is discovered.