1. History of Classification To organize information about the diversity of living things

2. Early Systems Aristotle’s system—either plants or animals-base on structure-morphology. Linnaeus’s system—two names-taxonomy binominal nomenclature using Latin-based on structure-morphology. Genus (capitalized) species name not capitalized.

3. Taxonomic Categories Taxon—a named group of organisms- genus. Order of organization: smallest to broadest Species Genus Family Order Class

4. Phylum Kingdom: Eubacteria, Archaea, Fungi, Plantae, Animalia Domain: broadest- 3 domains-Archaea, Eubacteria, Eukarya Mnemonic: Dynamic Kings Play Chess On Fuzz Green Stools

5. Modern Classification Typological species concept—based on the idea that species are unchanging distinct and natural types. When variations occurred it was called a new species. What kinds of useful information for classification do you think we know about today that early scientists didn’t know?

6. Answers: DNA, cell types, cell organelles, and evolution. Why is it not always correct to classify using the typological species concept?

7. Answer: two groups of animals that share some physical traits but are not closely related. Bats and birds is one example.

8. Other concepts of classification Biological species concept—species were redefined as organisms that are able to interbreed and produce fertile offspring— Mayr and Dobzhansky (1930s-1940s). Phylogenetic species concept— evolutionary species concept was proposed as a companion to biological species concept.

9. Phylogenetic species concept Phylogeny—is the evolutionary history of a species. Species is a cluster of organisms that is distinct from other clusters and shows evidence of descent and ancestry. Characters-patterns of descent. Morphological characters Biochemical characters—amino acids- nucleotides

10. Molecular clock Model that is used to compare DNA sequences from two different species to estimate how long the species have been evolving since they diverged from a common ancestor. Use molecular clocks indicate the rate of mutations which is not in uniform intervals.

11. Cladogram-also called a phylogentic tree Cladistics—is a method of analysis that classifies organisms according to the order that they diverged from a common ancestor It reconstructs phylogenies based on shared characters.

12. Character types Two main types of characters: ancestral characters and derived characters. A branching diagram that represents the proposed phylogeny or evolutionary history of a species or group. The groups used in a cladogram are called clades.