Phylogeny Flashcards
Branch
A line representing a population over time
Taxon
Represent species
Branch Point (node)
A location in the tree where splitting into two or more branches occur
Polytomy
Branch point with 3 or more descendants
Sister groups
Share an immediate common ancestor at node where branches meet
Outgroup
Lineage that diverges early on the phylogenetic tree
Differentiate between ancestral and derived trait
Ancestral Trait - traits that are seen in the ancestor group
Derived Trait - traits that arise during evolution of a group and differ from traits of the ancestor of group
Clade
Includes an ancestral species and all its descendants
Monophyletic
A valid clade, consists of ancestor species and all its descendants
Polyphyletic
Consists of various species that lack a common ancestor
Paraphyletic
Ancestral species and some, but not all, of its descendants
Synapomorphy
Shared, derived trait common between descendants and their most recent common ancestor (trait is missing in more distant ancestors)
Allows recognition of monophyletic groups
Autapomorphy
Derived trait that is unique to a particular taxon
Parsimony
Choosing simplest explanation accounting for observations
Choose most parsimonious tree (fewest independent genetic events)