BIOB51H3 Lecture Notes - Lecture 5: Polytomy, Synapomorphy, Symplesiomorphy
Document Summary
Biob51 lec 05 & 6 notes p. 109-123, 137-139. An evolutionary tree is a diagram showing the history of divergence and evolutionary change leading from a single ancestral lineage to a suite of descendants. Depicts a group of organisms" genealogical relationships as they are understood according to darwin"s theory of descent with modification from common ancestors. How to read time on an evolutionary tree. Time flows from the root along the trunk, through the branches, towards the twigs. The root is on the left and time proceeds from left to right. How to read relationships on an evolutionary tree. Evolutionary relationships among species on a phylogeny are defined by the relative time elapsed since they last shared common ancestors. Sister species: share a more recent last common ancestor with each other than either shares with any other species. Many details of evolutionary history are missing from any given phylogeny.