AP Bio Unit 7 || Natural Selection and Phylogeny

Evolutionary Relationships are determined by:

• DNA

• FOssil Records

• Proteins

• Homologous Structures

Nodes

Represent a common Ancestor

Clades

Nodes and all branches formed from it

Sister Taxa

Two clades that emerge from the same node

Basal Taxon

Lineage that evolved from the root and remains unbranched

Root

Common ancestor of all the species

Synapmorphy

A derived charecteristic shared by clade members

Derived charecteristic

Similarity inherited from the most recent common ancestor of an entire group

Ancestal charecteristic

similarity that arose prior to the common ancestor

Outgroup

A linage that is the least closely related to the rest of the organisms

Monophyletic group

A single common ancestor and all of its descendents

Paraphyletic

A common ancestor and some of its descendents

Polyphyletic

A grouping with no recent common ancestor

Principle of Parisomy

The simplest evolutionary tree is likely to be correct.