Chapter 4 Flashcards
What is the root in a phylogenetic tree?
Most recent common ancestor of all the taxa in that tree.
What is an outgroup?
Group of taxa more distantly related to the ingroup.
What are tips in a phylogenetic tree?
The ends of the branches that point to the taxa.
What are nodes in a phylogenetic tree?
Where the branches split.
What is the Most Recent Common Ancestor?
The last ancestor two animals share.
What are sister taxa?
Groups of organisms that are the closest relatives of each other and share a common ancestor.
What is a polytomy?
A node in a phylogenetic tree where more than two branches split off from a single ancestral branch (indicates uncertainty).
What is the difference between monophyletic and paraphyletic groups?
Monophyletic groups include all descendants of a single ancestor, while paraphyletic groups include some descendants but not all.
What is a cladogram?
Tips are aligned; branch lengths do not matter.
What is a phylogram?
Branch lengths represent genetic divergence.
What is a chronogram?
Branch lengths represent time.
What are homologous traits?
Traits found in two or more (related) species because they inherited the trait from a common ancestor.
What are analogous traits?
Traits shared by two or more species, NOT from common descent, but from independent evolution (e.g., convergent evolution).
What is convergent evolution?
When a trait evolves multiple times independently.
