BIOL 3301 ch3

Homologous characters

inherited from a common ancesotr

homoplasious characters

evolved independently

phylogeny

Study of evolutionary history and relationships among individuals or groups of organisms

evolutionary relationships

Understanding how different species are related to one another through common ancestry

what do phylogenetic trees shos

inferred evolutionary relatioshops no phenotypic similarities

nodes

where branches split

branch point

Represents Divergence of Lineages

sister taxa

Groups that share immediate common ancestor

rooted tree

Includes branch to represent last common ancestor of all taxa in tree

basal taxon

diverges early in history of a group, originates near common ancestor of group

polytomy

branch from which more than two groups emerge

how are all organisms related

descendance, closely related species share characteristics because of common ancestor

ancestral

character state that was present in common ancestor

derived

characters that arose later

synapomorphy

derived character shared by members of clade

monophyletic

group is a clade and all ancestors and descendants of that group

synamorphies arise from

evolutionary changes in the lineage leading up to most recent ancestor

parsimony

simplest scientific explanation that fits the evidence

how do we dinstiguish which feature is shared to ancestry vs similar forms

compare characters across taxa, search for similar form and position, test, homologous character due to common ancestry