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What conclusions can you make based on your observations of your geological timeline?

Warm Up 9/18/08. What conclusions can you make based on your observations of your geological timeline?. Ch 15.1 Notes. Natural Selection & Evidence for Evolution. Charles Darwin. English Scientist (1809-1892) Used fossils to shape ideas about evolution

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What conclusions can you make based on your observations of your geological timeline?

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  1. Warm Up 9/18/08 What conclusions can you make based on your observations of your geological timeline?

  2. Ch 15.1 Notes Natural Selection & Evidence for Evolution

  3. Charles Darwin English Scientist (1809-1892) Used fossils to shape ideas about evolution Suspected species change or evolve over time

  4. Darwin on HMS Beagle • Took many years to develop theory of evolution • Ships naturalist studies and collects specimens • Becomes curious about relationships • These studies provide foundation for his theory

  5. Darwin in Galapagos Islands • Group of small islands near equator • Species were unique to island but similar to species elsewhere • These observations led him to believe species change over time

  6. Darwin Continues His Studies • Works for another 20 years to refine his explanation • English Economist Thomas Malthus proposes idea about human population • Species produce large number of Offspring • Creates competition for food space an finding mates

  7. Natural Selection Mechanism for change in populations Organisms with favorable variations survive and reproduce These variations are passed on to next generation

  8. Interpretation of Evidence Volumes of data collected Subject to interpretation Processes are difficult for humans to observe Genetics has added more data

  9. Part Two Adaptations: Evidence for Evolution

  10. Structural Adaptations • According to Darwin’s theory species adaptations occur over many generations • Study the Mole–rat: Lives in ground and has many adaptations , is blind, has big claws, large teeth • MIMICRY is a structural adaptation that enables one species to look like another • CAMOUFLAGE adaptations that allow species to blend in environment

  11. MIMICRY

  12. Camouflage

  13. Physiological Adaptations • Most structural adaptations develop over a millions of years • Physiological adaptations evolve quicker • Physiological adaptations are changes in organisms metabolic processes • Example: antibiotics and pesticides

  14. Fossils • Provides record of early life • Ancestors of whales where dog like creatures • The fossil record is incomplete • Like putting together a jigsaw puzzle

  15. ANATOMY • Look at forelimbs of whale, crocodile, and bird • Evidence that animals evolved from common ancestor • Homologous Structures: structural features with common evolutionary origin • Analogous Structure: do not have common evolutionary origin but have similar function • Vestigial Structure: body structure in modern day organism that no longer serves it original purpose

  16. Homologous Structures

  17. Analogous Structures

  18. Vestigial Structures

  19. Embryology • Easy to distinguish between adult organisms but can you distinguish between there organisms? • It is the shared features in the young embryos that suggest evolution from an distant common ancestor

  20. Biochemistry Provides strong evidence for evolution Nearly all organism share DNA, ATP and many enzymes Organisms that are biochemically similar have fewer differences in their amino acid squences

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