Evolution

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Evolution

• Unit Organization

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Evolution Breakdown

• What is the nature of science?
• Who was Chuck D.?
• What is the evidence for evolution?
• How does evolution work?
• Where do humans fit in?
• Why does evolution matter now?
• Controversy anyone?

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The Nature of Science

• Hypothesis ? a possible and testable statement
  about a natural phenomenon.
• Ex. Newton proposed that the force of gravity
  between two objects depends on the distance
  between the objects.

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The Nature of Science

• Theory ? a well-substantiated explanation of some
  aspect of the natural world that typically
  incorporates many confirmed observations, laws,
  and successfully verified hypotheses.
• Ex. Heliocentrism the sun is the center of our
  solar system
• This is a special definition for science. What
  is a definition for theory outside of science?

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The Nature of Science

• Law ? a description of how a natural phenomenon
  will occur under certain circumstances
• Ex. Keplers Law of Planetary Motion describes
  the relationship between the time it takes a
  planet to go around the Sun and the planets
  distance from the Sun.

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The Nature of Science

• Fact ? a natural phenomenon repeatedly confirmed
  by observation
• Ex. It takes Venus 225 days to go around the Sun.

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Who Was Charles Darwin?
http//evolution.berkeley.edu
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Who Was Charles Darwin?

• This was his plight.

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Who Was Charles Darwin?
Voyage of The Beagle
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Who Was Charles Darwin?

• In 1831 twenty-two year-old Charles Darwin
  embarked on a five-year voyage on HMS Beagle
• purpose to chart the coasts of Patagonia and
  Tierra del Fuego
• but Darwin also recorded his observations on the
  natural history of plants and animals in
  countries then little known to European
  naturalists.
• Darwin was not yet an evolutionist, but later he
  would say the trip "was the most important event
  in my life and has determined my whole career"

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Who Was Charles Darwin?

• Darwin was acutely aware that public challenges
  to Creationism were considered heretical
• dangerous to his career and family.
• Spent 1/3 of his life doubled up, trembling,
  vomiting, and dowsing himself in icy water.
• He sat on his theory of evolution for twenty
  years!

Darwin and Victorian Culture
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Charles Darwins letter to the Gardeners
Chronicle and Agricultural Gazette, April 14, 1855

• I have begun making some experiments on the
  effects of immersion in sea-water on the
  germinating powers of seeds, in the hope of being
  able to throw a very little light on the
  distribution of plants, more especially in regard
  to the same species being found in many cases in
  far outlying islands and on the mainland. Will
  any of your readers be so kind as to inform me
  whether such experiments have already been tried?
  And, secondly, what class of seeds, or particular
  species, they have any reason to suppose would be
  eminently liable to be killed by sea-water?

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What is the evidence for evolution?

• Three basic categories
• Fossil (paleontology)
• Anatomical
• Molecular
• check out your ½ sheet evolution concept map!!

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Fossil Evidence Relative dating

• Can tell general time frame by the rock layers
  surrounding the fossil
• Lower levels are older or younger?

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Fossil Evidence Radiometric Dating

• More exact (also called absolute dating)
• For Carbon-14, sample must have been alive
• Can date rocks accurately
• Check out the back of the video wkst!

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Fossil Evidence

• Transitional Forms
• Examples

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Anatomical Evidence

• Homologous Structures ? same body plan suggests
  common ancestor -- video

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Homologous Structures
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Anatomical Evidence

• Vestigial Structures
• Evidence of a past when parts/organs might have
  been used
• vestige noun 2 a bodily part or organ that is
  small and degenerate or imperfectly developed in
  comparison to one more fully developed in an
  earlier stage of the individual, in a past
  generation, or in closely related forms.

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Vestigial Structures (cont.)
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Vestigial Structures (cont.)
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Vestigial Structures (cont.)
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Molecular Evidence

• Now we can look at molecular similarities /
  differences to draw conclusions
• Lab ? Fish Proteins

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Molecular Evidence (cont.)
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Molecular Evidence (cont.)
Other examples -Bacterial Article -AIDS court
case -Bird Flu (H5N1)
Explain the relationship between the seasonal flu
virus and evolution. What is the concern with
the H5N1 strain of avian flu?
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How Does Evolution Work?

• How did finch speciation work?

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How Does Evolution Work?

• How did Teddy Graham evolution work?
• Would drinking more milk confer an evolutionary
  advantage? You decide.

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How Does Evolution Work?
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How Does Evolution Work?

• Which two hypotheses were suggested to explain
  how domestic dogs came from wolves?
• Which one do you accept?

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The Barber Clan 2006
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The Barber Clan 2007
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The Barber Clan 2008
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How Does Evolution Work?

• Peacock Evolution
• Click for video

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How Does Evolution Work?
MHC
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How Does Evolution Work?
http//evolution.berkeley.edu
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Natural Selection at work
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More Natural Selection
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Where do mutations fit?

• Genetic mutations arise by chance. They may or
  may not equip the organism with better means for
  surviving in its environment. But if a gene
  variant improves adaptation to the environment
  (for example, by allowing an organism to make
  better use of an available nutrient, or to escape
  predators more effectively--such as through
  stronger legs or disguising coloration), the
  organisms carrying that gene are more likely to
  survive and reproduce than those without it. Over
  time, their descendants will tend to increase,
  changing the average characteristics of the
  population.

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Where do Humans fit in?

• Bones / Skulls tell us
• Who (many species)
• What (meat or plants)
• Where (Africa / Asia)
• When (carbon dating)
• How (size, walk, gender, death)

If you compared the peoples of Africa genetically
and then compared the peoples of Europe
genetically, what would you find? What does it
suggest? Do other categories of evidence support
this?
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Why does it matter?

• Dr. Chengs Zebrafish

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Controversy Anyone?

• Read like the wind!
• There should not be any controversy.
• Science never, ever, ever, ever wants to
  interfere with your beliefs!
• What was the Intelligent Design ruling from
  Harrisburg?

Ken Miller on the Colbert Report
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The Evolution Game
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Sea Monster Game