04_Ward_Inferring_trees_Outline

04_Ward_Inferring_trees_Outline - BIS2C W2011 Building...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
BIS2C W2011 Lecture 4 (7 January 2011) 1 Building trees (part 2) Today’s lecture revisiting monophyly, unrooted trees, branch lengths, and step counting building trees: model-based approaches Recapping some points If terminal taxa are individual species: they may or may not be monophyletic. If terminal taxa are higher taxa (groups of species): monophyly is assumed (or else they wouldn’t be drawn as a single branch). Unrooted trees can float freely and the branches of the trees can rotate around internal nodes without changing the meaning. Unrooted trees are different when neighbors (adjacent taxa) are different. What do “steps” or “character state changes” mean? A population-level process in which one state become substituted for another. Evaluating steps (character state changes) on trees Character conflict and how to deal with it. Building trees: model-based approaches Maximum likelihood : develop a probabilistic model of character evolution; search for most likely tree (ML tree) under that model. Advantages and disadvantages of ML.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/09/2011 for the course BIS 2 taught by Professor Coolprof during the Spring '11 term at Bank Street College of Education.

Page1 / 2

04_Ward_Inferring_trees_Outline - BIS2C W2011 Building...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online