2. Taxonomy The classification of living things….

3. There may be over 100 million different living things on Earth. Less than 2 million have been classified at this time. The science of naming and classifying living things is called taxonomy.

4. Naming a species: A species can be scientifically named using binomial nomenclature (two name). This means that the organism is named using its genus and species name. The entire scientific name is always written in italics. The genus name is always capitalized Homo sapiens

5. The Hierarchy of Classification Carolus Linnaeus (1707- 1778) used binomial nomenclature to name living things which he placed in groups according to their characteristics. He proposed a hierarchy which had levels (taxa) that included a very broad range of organisms, like animals and plants, and more specific groups like genus and species.

6. Levels of Classification Kingdom Phylum Class Order Family Genus species

7. Classification of Humans Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo species sapiens

8. Evolutionary Classification Classification has changed over time from grouping based on physical characteristics to grouping based on evolutionary history and genetics Phylogeny – evolutionary relationships among organisms Derived characters – characteristics that appear in organisms that were not present in “older” organisms

9. Cladogram – shows evolutionary relationships between organisms

10. Molecular Clocks DNA (and mitochondrial DNA) is always changing and mutations happen all the time Scientists can tell how closely related organisms are based on differences in DNA and the subsequent amino acid sequences in proteins. Modern tool to help scientists classify organisms

11. Molecular Clocks..

12. How are all things classified? The “Kingdoms” have changed over time... 1700s – Plantae, Animalia 1800s – Protista, Plantae, Animalia 1950s – Monera, Protista, Fungi, Plantae, Animalia 1990s – Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia Why???

13. Six Kingdoms/Three Domains

14. The Three domains: Modern way to classify organisms Based on ribosomal RNA mutations (molecular clock) Eukarya – Eukaryotes Bacteria – Eubacteria Archaea - Archaebacteria

16. Phyla of the kingdom animalia: List of all? List Major phyla:

18. Classes in the Phylum Chordata Class Mammalia – mammals Class Pisces – fish Class Amphibia – amphibians Class Reptilia – reptiles Class Aves – birds Link to chart

19. Orders in the Class Mammalia Insectivora – shrew, mole Chiroptera – bats Primates – primates Lagomorpha – rabbits Rodentia – rodents Cetacea – whales and dolphins Carnivora – carnivores Proboscidea – elephants Perissodactyla – horses, rhinos Artiodactyla – antelope, giraffes, camels, pigs

20. Taxonomy The end…. Be prepared for a quiz tomorrow!!!