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BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts A. Phylogeny 1. Defined 2. Phylogeny vs. tokogeny 3. Clade and monophyletic group 4. Sister group BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts A. Phylogeny 1. Defined 2. Phylogeny vs. tokogeny 3. Clade and monophyletic group 4. Sister group Willi Hennig (German; 1913-1976) Grundzüge einer Theorie der Phylogenetischen Systematik (Hennig, 1950). BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts B. Cladogram 1. Defined 2. Styles 2. Branches and nodes; internal vs. external branches BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks 4. Homology, analogy, and homoplasy BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states e.g., useful characters for tetrapod phylogenetics 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks 4. Homology, analogy, and homoplasy Skeletal Limbs (legs): zero, four Fur: no, yes Tail: yes, no Bipedality: no, yes BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states e.g., useful characters for tetrapod phylogenetics 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks Skeletal Limbs (legs): zero, four Fur: no, yes Tail: yes, no Bipedality: no, yes 4. Homology, analogy, and homoplasy Outgroup: fish (also some invertebrate) Ingroup: (amphibians, reptiles, monkeys, nonhuman apes, humans) BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks 4. Homology, analogy, and homoplasy Birds Bats Insects BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks 4. Homology, analogy, and homoplasy Modern cetaceans: vesitigial pelvis &, occassionally hind “limbs” BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts C. basilosaurids and dorudontids (ca. 40-30 Ma) Characters and homology 1. Cladogram as a framework for studying the origin of variation among species. 2. Characters and character states 3. Apomorphies vs. plesiomorphies Autapomorphy vs. synapomorphy Synapomorphy vs. symplesiomorphy Hashmarks 4. Homology, analogy, and homoplasy Basilosaurus had 2 tiny legs, probably used as claspers when mating. BIOL 471 – Methods in Systematics: Topic -- Phylogenetics II. Cladistics A. The taxon-by-character matrix BIOL 471 – Methods in Systematics: Topic -- Phylogenetics II. Cladistics B. Synapomorphies as evidence of recency of common ancestry 1. Ingroup vs. outgroup 2. Parsimony and Ockham’s Razor 3. Parsimony the optimality criterion as a means of dealing with incongruence BIOL 471 – Methods in Systematics: Topic -- Phylogenetics BIOL 471 – Methods in Systematics: Topic -- Phylogenetics II. Cladistics C. Minmizing “steps” is the practical application of parsimony BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Snail Hagfish Perch Salamander Lizard Mouse Chimp Human BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Lungs, 4-legs vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Claws or nails Lungs, 4-legs vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Fur; mammary glands Claws or nails Lungs, 4-legs vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Loss of tail Fur; mammary glands Claws or nails Lungs, 4-legs vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics Loss of tail Fur; mammary glands Claws or nails 10 “steps” Lungs, 4-legs vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? vertebrae; jaws vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? Lungs, 4-legs Lungs, 4-legs vertebrae; jaws vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? Claws or nails Claws or nails Lungs, 4-legs Lungs, 4-legs vertebrae; jaws vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? Fur; mamm Fur; mammary glands Claws or nails Claws or nails Lungs, 4-legs Lungs, 4-legs vertebrae; jaws vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? Fur; mamm Fur; mammary glands Claws or nails Claws or nails Lungs, 4-legs Lungs, 4-legs vertebrae; jaws tail vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics How to evaluate an alternative cladogram? 17 “steps” Fur; mamm Fur; mammary glands Claws or nails Claws or nails Lungs, 4-legs Lungs, 4-legs vertebrae; jaws tail vertebrae; jaws Notochord; hollow dorsal nerve chord BIOL 471 – Methods in Systematics: Topic -- Phylogenetics II. Cladistics C. Minmizing “steps” is the practical application of parsimony BIOL 471 – Methods in Systematics: Topic -- Phylogenetics III. Sources of variation for characters A. Morphological and anatomical variation BIOL 471 – Methods in Systematics: Topic -- Phylogenetics III. Sources of variation for characters B. Genetic (e.g., DNA sequence) variation 1. Source of genetic data 2. Alignment of DNA sequences. BIOL 471 – Methods in Systematics: Topic -- Phylogenetics III. Sources of variation for characters B. Genetic (e.g., DNA sequence) variation 1. Source of genetic data 2. Alignment of DNA sequences. BIOL 471 – Methods in Systematics: Topic -- Phylogenetics III. Sources of variation for characters B. Genetic (e.g., DNA sequence) variation 1. Source of genetic data. 2. Alignment of DNA sequences. BIOL 471 – Methods in Systematics: Topic -- Phylogenetics I. Phylogenetic terms and concepts A. Phylogeny 1. Defined 2. Phylogeny vs. tokogeny 3. Clade and monophyletic group 4. Sister group