1. PHYLOGENY AND THE TREE OF LIFE Chapter 26 Sections 1-3 and 6

2. PHYLOGENY  Phylogeny- the evolutionary history of a species or group of species.  Based on a study called systematics- which focuses on classifying organisms and determining their evolutionary relationships.

3. TAXONOMY  Why is it important to give species a scientific name?  “Dog” refers to more than one species.  A specific organism has different names in different languages.  Reduces ambiguity between communicating scientists.  Binomial Nomenclature- 2 part naming system  Always written in italics, with first letter capitalized.  Name is written as Genus species (Latin)

4. HIERARCHICAL CLASSIFICATION

5. PHYLOGENETIC TREES  Phylogenetic Tree- a branching diagram that represents the evolutionary history of a group of organisms.

6. ANALOGOUS VS. HOMOLOGOUS  Homoplasies- analogous structures that arose independently.  Ex: bat wings and bird wings  The more complex similar characteristics are, the more likely they are to be homologous over analogous.

7. EVALUATING MOLECULAR HOMOLOGIES

8. WARM UP EXERCISE  What is the basis for phylogenetic trees?  Why is it necessary for scientists to give organisms a scientific name rather than using a common name?  Name the 8 levels of classification and list the three domains.

9. CLADISTICS  Cladistics- a system of using common ancestry to classify organisms.  Clades- includes an ancient ancestral species and all descendants.

10. TYPES OF CLADES  Monophyletic- ancestral species and all of its descendants.  Paraphyletic- ancestral species and some, but not all, o fits descendants.  Polyphyletic- includes taxa of different ancestors.

11. CLADES  Shared Ancestral Character- originates in an ancestor of the taxon.  Shared Derived Character- shared by many organisms but not found in the common ancestor.

12. BRANCH LENGTHS AND GENETIC CHANGE  lj

13. BRANCH LENGTHS AND GEOLOGIC TIME  kj

14. PHYLOGENETIC PRINCIPLES  Principle of Maximum Parsimony (Occam’s razor)- most parsimonious tree requires the fewest evolutionary events.  Principle of Maximum Likelihood- shows a tree that represents the most likely sequence of evolutionary events. ALL PHYLOGENETIC TREES REPRESENT A HYPOTHESIS ABOUT EVOLUTIONARY RELATIONSHIPS

17. WARM UP  Describe the two principles that scientists use when coming up with phylogenetic trees.

18. EARLY CLASSIFICATION: KINGDOMS  Originally: 2 Kingdoms: Plant and Animal  1960s: 5 Kingdoms: Plant, Animal, Fungi, Protist and Monera  Now: 3 Domains  Bacteria- most currently known prokaryotes  Archaea- diverse prokaryotes that live in harsh environments- some use hydrogen as energy, others use natural gas deposits.  Eukarya- all organisms containing a nucleus. Includes some single-celled organisms (protists).

19. DOMAINS/KINGDOMS (CURRENT)  Bacteria  Eubacteria  Archaea  Archaebacteria  Eukarya  Plantae  Animalia  Fungi

20.  kj