BIOL 142 Chapter 23 Study Guide for TEST 1

BIOL 142 Chapter 23 Study Guide for TEST 1 - A clade is an...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
BIOL 142: Study Guide for TEST # 1 Chapter 23 – Systematics and Phylogeny Systematics – the study of evolutionary relationships Phylogeny – a hypothesis about patterns of relationship among species – usually represented as “trees” In a phylogenetic tree : Movement up, away from the base of the tree represents evolutionary changes in time toward present day Twigs represent existing species Places where branches come together represent recent common ancestors The trunk of the tree represents the common ancestor to all branches.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: A clade is an evolutionary unit referring to a common ancestor and all of its descendents (i.e., an entire, branch of the tree that is separate from other branches). Another way to describe a clade is as a monophyletic group . Groups that are NOT monophyletic can be: paraphyletic = does not include all of the descendents of a common ancestor polyphyletic = does not include the most recent common ancestor of members of the group...
View Full Document

This note was uploaded on 09/18/2011 for the course BIO 142 taught by Professor Jarrell during the Spring '11 term at Delgado CC.

Ask a homework question - tutors are online