1. An Introduction to Classification November 29, 2010

2. How many organisms are there in the world?

3. There are thought to be between 2 and 100 million species on earth Approx. 50 000 Vertebrates Approx. 1.4 million Invertebrates – 1 million insects! Only approx. 5 000 mammals.

4. Classification System Why classify organisms? In order to organize the vast number of species according to biological similarities and differences To make studying them easier To provide information about related organisms and ancestry

5. The Science of Classification

6. Taxonomy through the years... First: Aristotle first introduced two key concepts of modern taxonomy Classification of organisms by type BinomialBinomial Definition (what does that mean?) Wrote “History of Animals”

7. Consisting of or relating to two names or terms

8. Classified animals according to similarities: Those that fly Those that live on land/water NO GENETIC RELATIONSHIP Related organisms that may not be genetically related What about those that don't fit the general classification? Named animals according to Family and Difference: First by similarities, then differentiate specific characteristics

9. And then... Carolus Linaeus published “Systema Naturae” which organized all plants and animals from Kingdoms down to Species Created essential system we use today, though not as detailed First taxonomist to group humans with primates

10. Finally... Modern System brought more scientific understanding to Linnaeus' work Connected classification to Darwin's Theory of Evolution Began considering genetic connections between organisms

11. Modern Taxonomy Begin by grouping organisms according to general characteristics At each stage of classification, group organisms according to more specific criteria

12. Most specific level of classification – Species – are considered to be a morphologically and physiologically similar group of organisms that are able to produce offspring morphologicallyphysiologically

13. The form and structure of an organism or it's parts

14. Relating to the function of an organism or it's parts

15. Taxonomy What systems do modern scientists use to classify organisms? Taxonomic: based on structural and physiological similarities between organisms Phylogenic: based on genetic connections between organisms

16. Phylogeny Phylogeny is the branch of Biology where scientists study the evolutionary history of living organisms

17. Making Connections Modern taxonomists can classify organisms by connecting them to evolutionary relatives Several ways to do this...

18. Methods Fossil Records Cast a mold of organisms in rock and preserve structures to be studied and compared Homologous Structures Parts of different organisms that show similarities in their structure

19. More Methods Comparative Embryology Closely related organisms may have similar stages of early development Comparative DNA and RNA Investigates genetic similarities between organisms

20. What happens when scientists discover a new species that does not 'fit in' to the current structure?

21. What are the levels of Classification? General KINGDOM PHYLUM CLASS ORDER FAMILY GENUS Specific SPECIES

22. How can we remember this? Acronyms!! Allow us to create a phrase that we can more easily remember using the first letter of each word that we need to know Kingdom Phylum Class Order Family Genus Species King Phillip Came Over For Good Soup Kids Playing Catch On Freeways Get Smashed

23. Now you try... Create your own acronym using KPCOFGS

24. Answer the following questions: What does the acronym: Kids Playing Catch On Freeways Get Smashed Stand for? What is the science of classification called? Who was Carl Linaeus and what was his contribution to the science of classification?

25. Dichotomous Keys A map to follow when classifying organisms At each stage organisms are differentiated according to more specific characteristics. Scientists use them when they discover new species to determine the possible classification of their organism, and to create a map for other scientists that may want to classify that organism.

26. Binomial Nomenclature A two name system of identification We name organisms according to Genus and Species. The first name is General, the second is Specific. We use Latin terms for naming (it is the universal language of science) Names are Italicized and the first letter of the Genus is capitalized. Example: Homo sapiens