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Classification and Phylogenic Trees

Classification and Phylogenic Trees. Notes #36 I can: Identify how classification has changed over time Read a phylogenic tree. Because of evolution there is great diversity of life!. Scientists need to organize over 2 million organisms!.

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Classification and Phylogenic Trees

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  1. Classification and Phylogenic Trees Notes #36 I can: Identify how classification has changed over time Read a phylogenic tree

  2. Because of evolution there is great diversity of life!

  3. Scientists need to organize over 2 millionorganisms!

  4. Scientists need to organize over 2 millionorganisms!

  5. Classification Classification: grouping organisms based on common ancestors and characteristics.

  6. History of Classification

  7. But is everything a plant or an animal? 1. Aristotle classified organisms as either plants (plantae) or animals (animalia)

  8. 2. Carolus Linneaus developed the hierarchical system, which classifies in levels based on physical similarities

  9. most general King Phillip came over for good most specific spaghetti

  10. Carolus Linneas also developed the system of binomial nomenclature = naming organisms with two names. The scientific name of an organism always consists of its genus name and its species name. Genus: Second most specific level Most specific level Species: Homo sapiens Genusspecies

  11. What genus does this organism belong to? What species? Canis familiaris dog

  12. What genus does this organism belong to? What species? Felis domesticus cat

  13. Problems with Classification What kinds of problems could scientists run into if they were just grouping organisms by similar physical characteristics?

  14. Problems with Classification What kinds of problems could scientists run into if they were just grouping organisms by similar physical characteristics? Turn and Talk

  15. Modern Classification Biologists now group organisms according to their evolutionary relationships

  16. Scientists use the following criteria to classify organisms: • Structural similarities: similar fossils or anatomy • Biochemical analysis: DNA, proteins and amino acids (still the best) • Embryology: similar embryos

  17. Phylogenetic trees (aka cladogram)

  18. Phylogenic trees show when in time traits developed You can use them to: 1. Find which organisms are most primitive. 2. Find which organisms are most closely related

  19. Phylogenic trees show when in time traits developed You can use them to: 1. Find which organisms are most primitive. 2. Find which organisms are most closely related

  20. Primitive = old, simple The most primitive species are at the bottom (left) The most recent species are at the top (right) Primitive:

  21. Most primitive Most recent

  22. Common Ancestry Each branch point represents the common ancestor of two species.

  23. Organisms have the traits that come before them ex. everything after the Perch has lungs ex. What characteristic does the salamander have that the perch lacks? Species are closely related if they branch off close together

  24. Think: In the cladogram, what species is most primitive? In the cladogram, what species is least primitive? What traits does the lizard have? What traits does the salamander have? What is the chimp most closely related to? Is the lizard more closely related to the salamander or the perch?

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