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Evolution

Evolution. Mrs. Rago Honors Biology. Evolution. Development of new types of organisms from already existing organsims. Geology. Strata Rock layers Scientists can examine strata to find evidence for evolution. Charles Darwin. On the Origin of Species Book published by Darwin

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Evolution

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  1. Evolution Mrs. Rago Honors Biology

  2. Evolution • Development of new types of organisms from already existing organsims

  3. Geology • Strata • Rock layers • Scientists can examine strata to find evidence for evolution

  4. Charles Darwin • On the Origin of Species • Book published by Darwin • English scientist who developed theory of evolution • Studied species on the Galapagos Islands • Observed the species to compare features from each

  5. Finches • 13 different species of finches, all descended from a few ancestral finches • Type of Evolution • Adaptative Radiation • Finches changed over many generations in order to eat certain food

  6. Examples • Each finch with a different style beak feeds on different things

  7. Natural Selection • Mechanism for change in populations • Occurs when an organism with certain variations (characteristics) survive, reproduce, & pass on their variations to the next generation • These variations make the organism more likely to survive and reproduce • Types of Natural Selection • Overproduction, Genetic Variation, Struggle to Survive, Differential Reproduction

  8. Overproduction • The more offspring that are produced, the high the likelihood that an organisms genes will be passed on • Example: • If a female insect were to lay 1,000s of eggs and another female insect were to lay only a few 100, the female that laid 1,000s of eggs would be more likely to pass on her genes to the next generation

  9. Genetic Variation • Different traits make it more likely that an organism will survive • Example • Deer that have thicker fur tend to have offspring with thicker fur • Deer with thicker fur will be more likely to survive in an environment that is colder

  10. Struggle to Survive • Individuals compete with each other to survive • Example • If the only leaves left on the trees are at the top, then an organism with a long neck is going to reach those leaves and live on to produce offspring

  11. Differential Reproduction • Organisms with the best adaptations are most likely to survive • Survival of the fittest • Example • Marine Iguana

  12. Reproduction in Natural Selection Favorable traits make individual more likely to survive & reproduce Individuals with the best traits pass them on to their offspring

  13. Artificial Selection Breeding organisms to produce offspring with identical traits Example: breeding pure bred dogs

  14. On the Origins of Species Book by Charles Darwin First book on evolution

  15. Structural Adaptations • Changes that have developed in an organism’s form over time • Example: thorns on some plants • Take a long time to occur • Millions of years

  16. Mimicry Structural adaptation that allows one species to resemble another species Useful for a harmless species to resemble a harmful species, so that predators avoid the harmless species

  17. King snake-non venomous Coral snake- venomous & deadly

  18. Camouflage • An adaptation that allows a species to blend into their surroundings and avoid predators

  19. Physiological adaptations • Occur much faster • Changes in an organisms metabolic processes • Example: resistance to penicillin, insects & weeds resistant to specific pesticides

  20. Evidence for Evolution • Fossil record • Shows evidence of evolution but it is incomplete • Superposition • Lowest layer of rock is the oldest and newest layer is at the top • Can tell the relative age of a fossil • Radiometric dating • Can tell absolute age of the rock

  21. Anatomy • Homologous structures • Similar structures that come from a common ancestor

  22. Analogous Structures • Similar structures that are similar because they are used for the same purpose

  23. Vestigial Structures • A body structure that has no function in a present-day organism but was probably useful to an ancestor • Example: wings of an ostrich

  24. Embryology • Embryo is the earliest stage of growth & development of both plants & animals

  25. Biochemistry • Evidence for evolution, shows similarities in DNA or RNA

  26. Timeline of evolution on earth • Archaebacteria • Old species that was present when earth was forming • Cyanobacteria • Photosynthetic, unicellular prokaryotes • Produces oxygen as biproduct

  27. Endosymbiotic theory • Large prokaryote & small aerobic prokaryote come together and form primitive eukaryote • primordial soup • A liquid rich in organic compounds, providing favorable conditions for the emergence and growth of life forms

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