BIOL 1200 Midterm: Exam 2 Study Guide Part 3
Document Summary
Can you name the major components of a phylogenetic tree? (e. g. , root, node, branch, sister group, outgroup, etc. ) How are phylogenetic trees constructed: using similarities in trait/characteristics (synapomorphies) to reconstruct evolutionary history in species. Who was the biologist who gave us the phylogenetic approach known as cladistics: willi hennig. Distinguish between characters and character states: characters: the traits/ characteristics of a given organism (the traits that are being compared). Ex: teeth: character state: the form of given trait ex: sharp or smooth (can be derived or ancestral). A derived character state: ancestral: character that originated in an ancestor, derived: evolutionary novelty unique to a clade. How do you determine character polarity, i. e. , determine whether a character state is ancestral or derived: by using the outgroup method (comparing it with the outgroup and other taxa). Why are they important: synapomorphy: a shared, derived trait or character. They help give information to construct phylogenetic trees and show relationships.
