BIOL 117 Study Guide - Midterm Guide: Mitochondrion, Gram-Positive Bacteria, Synapomorphy
Document Summary
Lecture 3: phylogenies and the history of life. Tip: portrays the different groups of organisms represented by the tree. Root: the earliest ancestor of a given phylogeny. Outgroup: taxa/species of organism that is the least like the other groups of organisms. Node: represents a common ancestor species that splits into two descending species. Sister taxa/monophyletic group/clade: taxa that share a very recent common ancestor (are closely related) Anatomy of a phylogenetic tree: a phylogenetic tree can be rotated at any node and still convey the same information. Terminology: ancestral trait-a trait possessed by the ancestor species and its descendant species, derived trait-a characteristic that is modified from an ancestral trait, ancestor won"t possess trait but the descendant will, these definitions are subjective. This picture shows the ancestral and derived traits with respect to ancestor f. 3-1: in relation to ancestor f what is trait #1: ancestral trait, derived trait.
