BIOL 2400 Lecture Notes - Lecture 3: Reptile, Phenetics, Carl Linnaeus
12 Sep 2017
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What is a phylogenetic tree: phylogeny a visual representation of the evolutionary history of populations, genes or species, more closely related things are clustered/connected more closely, more similar things are assumed to be more closely related. Tree terminology: tips (leaf/terminal nodes) terminal ends of a tree representing species, molecules or populations. Internal node nodes within a phylogeny represent ancestral species: branches lineages evolving independently through time between speciation events, clade an organism and all of its descendants, cladogram phylogeny where time scale is not depicted. Synapomorphy: a homologous trait that is shared among groups based on descent, shared derived characters, distinguish derived groups. Are wings a synapomorphy or a homoplasy: homoplasy convergent evolution. Synapomorphy wings are shared and derived: homologous but not synapomorphy wings are shared but not derived. In which a trait can be lost and formed many times. Long branch of outgroup does not imply a lack of evolution or diversification.
