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Download leopard - Ms. Coonley
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Lecture 1: Classification OBJECTIVES: •Explain Phylogeny and describe the information presented in a Phylogenic Tree •Create a Cladogram •Explain data used to create Phylogenies What does the Linnaean System of Classification use to Classify Organisms? Physical Traits Are these two organisms closely related? Is this sufficient? What are the levels of Linnaean classification Domains • Archaea – Prokaryotic – Have unique ancient evolutionary history – Often live in extreme environments • Bacteria – Prokaryotic • Eukarya – Eukaryotes Kingdoms • Six Kingdoms – Domain Archaea • Kingdom Archaea – Domain Bacteria • Kingdom Bacteria – Domain Eukarya • • • • Kingdom Animalia Kingdom Fungi Kingdom Plantae Kingdom Protista Phylogeny • Evolutionary history of a species • Branching tree diagrams • To reconstruct phylogeny, scientists use cladistics Species Mephitis mephitis (striped skunk) Lutra lutra (European otter) Genus Panthera Mephitis Lutra Family Felidae Order Panthera pardus (leopard) Mustelidae Carnivora Canis familiaris (domestic dog) Canis Canidae Canis lupus (wolf) Leopard Domestic cat Each branch point represents the divergence of two species Common ancestor Wolf Leopard Domestic cat “Deeper” branch points represent progressively greater amounts of divergence Common ancestor Millions of years ago Neoproterozoic 542 Paleozoic 251 Mesozoic 65.5 Cenozoic What is Cladistics • Classification based on shared ancestry • Cladogram – Branching trees: closer the branches= more closely related – Clade • Group of species that share a common ancestor What is a Cladogram • Depicts patterns of shared derived characteristics among taxa – Synapomorphies • The more synapomorphies two species share, the more closely related they are • The chronological sequence of branching during the evolutionary history of a set of organisms How are Cladograms constructed? Morphological similarities Homologous structures Structures from a common ancestor Molecular Similarities Molecular Homologies DNA Organisms with very similar morphologies or DNA sequences are likely to be more closely related than organisms with vastly different structures or sequences
