Evolution by Natural Selection

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Evolution by Natural Selection
www.biblewheel.com/ History/C19_Evolution.asp

• ES 100 Environmental Ecology
• 9/26/05

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Roots of Ecology

• Relatively new science
• Carl von Linné (mid 1700s)
• classification of living things

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The Classification of Living Things

• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primata
• Family Hominidae
• Genus Homo
• Species Sapiens

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Roots of Ecology

• Carl von Linné (mid 1700s)
• classification of living things
• Alexander von Humboldt (early 1800s)
• botanical geography
• Charles Darwin and Alfred Wallace 1850
• animal geography
• theory of evolution by natural selection
• Ernst Haeckel 1866
• coined the term ecology
• Edward Suess 1875
• biosphere as the condition that promotes life
  it includes plants, animals, and non-living
  things
• Arthur Tansley 1935
• ecosystem concept interaction between living
  and non-living entities in the biosphere

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Hypotheses, Theories and Your Textbook
http//home.comcast.net/fsteiger/cartoon2.gif
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Theory of Evolution by Natural Selection

• Natural selection is the mechanism that explains
  evolution
• Natural Selection scale individual
• Evolution scale many generations

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Temporal Scale
Animation of whale evolution Click here
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Theory of Evolution by Natural Selection

• Natural selection is the mechanism that explains
  evolution
• Natural Selection scale individual
• Evolution scale many generations
• Darwins observations
• Organisms produce more young than can survive.
• All species exhibit genetic variability (from
  mutation and random combination of parents
  genes).
• Individuals with traits most suited to
  environment most likely to survive.
• Only survivors contribute to the gene pool.
• Theory Lineages with most appropriate biological
  programming (genes) for current environmental
  conditions will leave the most descendants.

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Bush, page 7

• Sickle-cell anemia, Downs syndrome, and color
  blindness are heritable, and each would reduce an
  individuals chance of survival in a wild human
  population

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When is Mutant Sickle-cell Gene Desirable?
www.sicklecelldisease-il.org/.../ what/how.html
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Natural Selection and Physical Appearance
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Optimal Foraging Theory

• Organisms that forage most efficiently will be
  more likely to reproduce (improve fitness)
• Thus, natural selection favors optimal foraging.
• Cost/benefit analysis
• What is foraging?
• What do plants and animals forage for?

police.ucsb.edu/ crime_prevent.html
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Natural Selection and Biochemical Traits
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Testing HypothesesObservation vs.
Experimentation

• Experimentation deductive approach
• Manipulate system by creating experiments
• Strength control variables
• Weakness not realistic

• Observation
• inductive approach
• See patterns in the field
• Strength grounded in reality
• Weakness mechanistically weak

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Natural Selection and Behavior
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Is Human-Environmental Behavior a Result of
Natural Selection?

• Genetically Based Reproductive Urges?
• Short-term Egoists?
• Altruism- inclusive fitness?
• Reciprocal Altruism?
• What are the implications for environmental
  management?

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Are Humans Exempt from Natural Selection?
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Defining evolution

• Scientific Definitions
• All the changes that have transformed life on
  earth from its earliest beginnings to the
  diversity that characterizes it today
  Neil Campbell
• The origination of species of animals and
  plants
  O.E.D.
• Common Usage
• A process of continuous change from a lower,
  simpler, or worse to a higher, more complex, or
  better state
• Merriam-Websters Dictionary
• From a scientific point of view, evolution is
  just how new species come about

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Humans as an Evolutionary Endpoint?
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Theory of Evolution Criticisms

• Microevolution is generally accepted, but
  macroevolution is hotly debated
• How does evolution add information to a genome to
  create progressively more complicated organisms?
• How is evolution able to bring about drastic
  changes so quickly?
• How could the first living cell arise
  spontaneously to get evolution started?

Basilosaurus
Ambulocetus
Pakicetus
Humpback
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Homework/Section this Week

• HW 1 passed out get started on s 1-3
• Internet assignment for section this week
• Visit course website
• Follow Evolutionary Feast link
• Prepare (typed) assignment and bring to section
• Bring food to section (can bring a form of the
  fruit/vegetable- chocolate instead of cocoa
  beans)
• Interested in an honors contract? See me.