2.3.1 Taxonomy and Classification

1. 2.3.1 Taxonomy and Classification

2. Classification The science of grouping organisms based on their similarities.

3. Why we classify? • To help identify organisms • To draw parallels and distinctions between organisms • To identify relationships between organisms • To communicate with others (universal language) • To identify evolutionary patterns and relationships

4. What’s the basis for classification? • Morphology (structures) • Physiology (functions) • Biochemistry • Genetics

5. TAXONOMY Scientists look for these similarities: 1. Anatomical 2. Biochemical 3. Embryological development 4. Evolutionary relationships

6. ARISTOTLE (384-322 B.C.) • Greek philosopher. • Came up with the 1st system of classification. 1. Plants: - stem types 2. Animals: - land, air or water

7. CarolusLinneaus (1707-1778) • Swedish botanist. • Came up with today’s modern system of classification.

8. 6 KINGDOMS Monera

9. Hierarchy of Classification • Kingdom • Phylum • Class • Order • Family • Genus • Species

10. Phylogenic Tree = each branch point represents a common ancestor of the species above that point.

11. Scientists use a 2-word system of naming different organisms called BINOMIAL NOMENCLATURE. • This 2-word name is called a SCIENTIFIC NAME and it is made up of the genus and species names.

12. A scientific name is either written in italics or it is underlined. • Genus is capitalized, species isn’t! St. John’s Wort: Hypericum perforatum Dandelion: Taraxacum officianalis Domestic cat: Felix domesticus Mosquito: Colex pipens Human: Homo sapiens Maryland blue crab: Calinectes sapidus

13. Plantae Plantae Animalia Animalia Anthophyta (flowering plants) Anthophyta Anthropoda Chordata Monocotyledonae (monocots) Monocotyledonae Insecta Mammalia Commelinales Orchidales Diptera Primates Poaceae Orchidaceae Muscidae Hominidae Zea Vanilla Musca Homo Z. mays V. planifolia M. domestica H. sapiens corn vanilla orchid housefly human KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES COMMON NAME: Fig. 20.11, p. 320

14. In order to identify new organisms and to figure out what species they are, scientists use a DICHOTOMOUS KEY. • By asking a series of “Yes/No” questions about the organisms anatomy, the organism can be identified.

15. A simple Dichotomous Key

16. A Complex Dichotomous Key

17. 1a. Hair present . . . . . . .Class Mammalia 1b. Hair absent . . . . . . . Go to 2 2a. Feathers present . . . . Class Aves 2b. Feather absent .. . . . Go to 3

18. 3a. Jaw present . . . . . . .Go to 4 3b. Jaw absent . . . . . . . Class Agnatha 4a. Paired fins present . . . . Go to 5 4b. Paired fins absent .. . . . Go to 6

19. 6a. Skin scales present . . .Class Reptilia 6b. Skin scales absent . . . Class Amphibia

20. 1a. Body symmetry radial . . . . . . . . . . Go to 2 1b. Body symmetry not radial . . . . . . . Go to 3 2a. Tentacles present, body soft . . . . . P. Cnideria 2b. Tentacles absent, body hard & rough . . . . . P. Echinodermata

21. 1a. Body symmetry radial . . . . . . . . . . Go to 2 1b. Body symmetry not radial . . . . . . . Go to 3 3a. Exoskeleton present . . . . . . . . . . . . Go to 4 3b. Exoskeleton absent . . . . . . . . . . . . . Go to 5

22. 4a. Jointed legs present . . . . . . . . . . P. Arthropoda 4b. Jointed legs absent . . . . . . . . . . . P. Mollusca

23. 1a. Body symmetry radial . . . . . . . . . . Go to 2 1b. Body symmetry not radial . . . . . . . Go to 3 3a. Exoskeleton present . . . . . . . . . . . . Go to 4 3b. Exoskeleton absent . . . . . . . . . . . . . Go to 5

24. 4a. Jointed legs present . . . . . . . . . . P. Arthropoda 4b. Jointed legs absent . . . . . . . . . . . P. Mollusca