BI111 Lecture Notes - Lecture 12: Phylogenetic Tree, Monophyly, Polyphyly
Document Summary
Bi111- lecture 12 january 30th, 2017- biological diversity and population. Individuals show evidence of mosaic evolution (evidence of a common ancestor: past is always changing. Combination of ancestral and derived characters in evolutionary lineage. Derived characters determined from fossils and embryos. Derived (not all derived traits are adaptations, or something different that isn"t found in the common ancestor) characters appear later in development (derived traits from ancestor) Outgroup comparison for derived characters (outliers possess traits that did not derive from focused species) Principle of monophly: all groups in a clade includes a common ancestor and all of its descendants, unless other data suggests that its more complicated. Principle of parsinomy: simplest explanation most likely to be correct. All phylogenetic trees are hypotheses that attempt to accurately reflect historical events. Monophyletic taxon- includes an ancestral species and all of its descendants. Polyphyletic taxon- includes species from different evolutionary lineages. Paraphyletic taxon- include an ancestral species and only some of its descendants.
