Phylogenetics Flashcards
Define Taxonomy
The science and system of classifying organisms
Define Taxon
Plural (taxa) = A single level in the taxonomic classification system
Define Phylogenetic Systematics
The science and system of classifying organisms to reflect their phylogeny
Define Phylogeny
Evolutionary History
Define Monophyly or Monophyletic
Derived from a single common ancestor
Define Clade
A monophyletic group
Define Synapomorphy
A trait shared by two or more clades (taxa) and most recent common ancestor
Define Paraphyletic
One or more missing descendants
Rooted Phylogenetic Trees Define Root, Branch Point, Basal Taxon, Sister Taxon, and Polytomy
Root = common ancestor to all organisms on the tree.
Branch point = where two lineages diverged.
Basal Taxon = a lineage that evolved early and remains unbranched.
Sister Taxa = when two lineages stem from the same branch point.
Polytomy = A branch with more than two lineages.
Define Homologous Characters
Inherited from a common ancestor, but may be serving a different function in descendents
Define Analogous Chharacters
Serve a similar function but originated as different characters in different ancestors
Define Evolutionary Convergence
Occurs when two organisms fill a similar ecological niche, which results in similar phenotypes
Define Ancestral Characters
Form found in ancestors
Define Derived Characters
Newly evolved traits
Define Homolgy
Shared ancestry
