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Concept 3: Classification and phylogenetic trees

Concept 3: Classification and phylogenetic trees. 11/14/13. Agenda for 4/24/14. Wake Up Work #3 Concept 3 Notes Video on Classification http:// www.youtube.com/watch?v=F38BmgPcZ_I. Wake Up Work #3.

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Concept 3: Classification and phylogenetic trees

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  1. Concept 3: Classification and phylogenetic trees 11/14/13

  2. Agenda for 4/24/14 • Wake Up Work #3 • Concept 3 Notes • Video on Classification • http://www.youtube.com/watch?v=F38BmgPcZ_I

  3. Wake Up Work #3 • What is the type of science used when looking at how fossils show relationships between evolutionary related organisms? • What is the difference in gene flow and genetic drift? • What is the difference between homologous structures and analogous structures?

  4. The Phylogenetic Tree • Phylogeny– evolutionary history of a species • Phylogenetic tree—diagram that biologists use to represent the phylogeny of organisms. • Speciationcould be thought of as a branching of a family tree, and extinction would be like the loss of one of the branches.

  5. Domains of Life: All of Life can be Organized into 3 Categories • Eubacteria: prokaryotic organisms; “true bacteria” • NO nucleus • ex: pathogens (bacteria that makes us sick) • Archaebacteria: prokaryotic “archaeans” • NO nucleus • Considered some of the oldest species • Live in extreme environments (bottom of ocean, volcanoes, salt water) • Eukarya: eukaryotic organisms • Contains a nucleus • Consists of all other organisms (plants, animals, fungi, protists, etc.)

  6. Classification of Living Things

  7. Kingdoms of Life: More Specific Levels of Classification Example:Classifyinga Brown Bear • Kingdom animalia (all animals) • Phylum chordata( all animals with a notochord) • Class mammalia (produces milk) • Order carnivora ( eat meat) • Family ursidae (dog like) • Genus ursus(black, brown and polar bears) • Species arctos (brown bears) “Kids Playing Chicken On Freeways Get Smashed”

  8. Classifying a Human • Kingdom—animalia (all animals) • Phylum—chordata (spinal cord) • Class—mammalia (produce milk) • Order—primates (shared teeth, skull, and arm characteristics) • Family—hominidae (chimps, gorillas, and humans) • Genus—homo (ancestral and modern humans) • Species—sapiens (modern human)

  9. Taxonomy: Write in Margin next to Bear Example

  10. Phylogenetic Trees • Understanding phylogeny is a lot like reading family tree. The root is the ancestral lineage, the tips represent descendants. As you move from root to the tips you are moving forward in time. • When a lineage splits (speciation), it is represented as branching on a phylogeny. • Classifies species in the order in which they descended from a common ancestor using physical characteristics Common Ancestor

  11. A speciation event occurred resulting in two lineages. One led to mosses of today and the other led to the fern, pine and rose. Since that speciation event, both have had an equal amount of time to evolve. Mosses are a “cousin” of other land plants.

  12. Phylogenetic trees show us: • Which groups are most closely related • Which groups are least closely related • Which group diverged first (longest ago) • Phylogenies don’t imply that organisms are more advanced than others.

  13. Phylogenetic Trees • Some phylogenetic trees only express the ORDER OF DIVERGENCE of a species. They do NOT attempt to show relative or absolute time frames.

  14. Phylogenetic Trees • Some phylogenetic trees indicate a TIME OF DIVERGENCE. • The branch b/w humans and whales is almost at the top of the line, while the branch between birds and tyrannosaurs happens about midway up the line, indicating that birds and tyrannosaurs diverged much sooner than humans and whales diverged.

  15. Misconceptions about Humans • Humans did not evolve from chimps • Humans and chimps are evolutionary cousins and share a recent common ancestor that was not human or chimpanzee • Humans are not “higher” or more evolved than other living lineages • Humans and chimps have each evolved traits separately

  16. A little practice!

  17. Tree A What is most closely related to the bushbaby? Which diverged first in this lineage, cats or lemurs? What was the first distinct species to diverge from this tree?

  18. Tree B: Which emerged first; slime molds or ciliates? What is most closely related to mathanobacterium?

  19. Vocab words from concept 1 • Evolution • Macroevolution • Microevolution • Natural selection • Overproduction of offspring • Variation • Sources of variation: • Mutation • Gene flow • Sexual reproduction • Adaptations • Descent with modification • Mechanisms of microevolution • Genetic drift • Genetic flow • Sexual selection • Hardy-Weinberg Equilibrium • 5 ways evolution will NOT occur • Speciation • Extinction • Gradual • Mass • Patters of Macroevolution: • Gradualism • Punctuated equilibrium • Adaptive Radiation • Convergent Evolution • Coevolution

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