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Evolution by Natural Selection

Evolution by Natural Selection. ES 100: Environmental Ecology 10/2/06. www.biblewheel.com/ History/C19_Evolution.asp. Roots of Ecology. Relatively new science Carl von Linné (mid 1700’s) classification of living things. The Classification of Living Things. Kingdom: Animalia

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Evolution by Natural Selection

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  1. Evolution by Natural Selection ES 100: Environmental Ecology 10/2/06 www.biblewheel.com/ History/C19_Evolution.asp

  2. Roots of Ecology • Relatively new science • Carl von Linné (mid 1700’s) • classification of living things

  3. The Classification of Living Things Kingdom:Animalia Phylum:Chordata Class:Mammalia Order:Primata Family:Hominidae Genus:Homo Species:Sapiens

  4. Roots of Ecology • Carl von Linné (mid 1700’s) • classification of living things • Alexander von Humboldt (early 1800’s) • 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

  5. Hypotheses, Theories and Your Textbook http://home.comcast.net/~fsteiger/cartoon2.gif

  6. Theory of Evolution by Natural Selection • Natural selection is the mechanism that explains evolution • Natural Selection: scale = individual • Evolution: scale = many generations

  7. Temporal Scale Animation of whale evolution: Click here

  8. Theory of Evolution by Natural Selection • Natural selection is the mechanism that explains evolution • Natural Selection: scale = individual • Evolution: scale = many generations • Darwin’s observations: • Organisms produce more young than can survive. • All species exhibit genetic variability (from mutation and random combination of parent’s 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.

  9. Bush, page 7: “Sickle-cell anemia, Down’s syndrome, and color blindness are heritable, and each would reduce an individual’s chance of survival in a wild human population”

  10. When is Mutant Sickle-cell Gene Desirable? www.sicklecelldisease-il.org/.../ what/how.html

  11. Natural Selection and Physical Appearance

  12. 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 SWEATY T-SHIRT EXPERIMENT: http://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.html

  13. Natural Selection and Biochemical Traits

  14. Testing Hypotheses:Observation vs. Experimentation • Experimentation: Manipulate system by creating experiments • Strength: control variables • Weakness: not realistic • Observation: • See patterns in the field • Strength: grounded in reality • Weakness: mechanistically weak

  15. Natural Selection and Behavior

  16. 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?

  17. Are Human’s Exempt from Natural Selection?

  18. 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-Webster’s Dictionary From a scientific point of view, evolution is just how new species come about

  19. Humans as an Evolutionary Endpoint?

  20. 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? Pakicetus Ambulocetus Basilosaurus Humpback

  21. Section this Week Internet assignment for section this week: • Visit course website • Follow “Feast of the Biomes” 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)

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