Lecture 4 Study Guide Flashcards
Taxonomy
The naming and classifying of organisms
Systematics
Classifications of organisms based on evolutionary relationships (phylogenetics)
Phylogeny
A hypothesis about patterns of evolutionary relationships
Phylogenetics
The reconstruction and study of evolutionary relationship
Operational taxonomic units (OTUs)
Terminal branch points indicating taxa, this could be a gene, organism, population, species, or species group
Branch
In the context of evolutionary trees, a branch depicts change over time leading from a bifurcation(node) to another bifurication or OTU
Node
Bifurcation point in an evolutionary tree that represents a speiation event
Characters
Traits of an organism (like basepairs or number of toes)
Outgroup
a more distantly related organism (or OTU) that serves to root a tree
Derived character state
A character state shared by a group of OTUs that is not the ancestral state
Synapomorphy
shared derived character state
Homoplasy
Independent evolution of similar traits may result from convergent evolution or an evolutionary reversal
Evolutionary reversal
return to an earlier character state (stick insects lost there wings)
Rapid diversification
3 or more species arising durring a short period of time
Incomplete lineage sorting
Occurs when ancestral gene copies fail to coalesce into a common ancestral copy until deeper than previous speciation events
Adaptive radiation
Evolution of a group into a wide variety of species each adapted to specialized conditions
Introgression
movement of genes from one species or population into another by hybridization, backcrossing, or horizontal gene transfer
Monophyletic group
represents a single evolutionary group containing the ancestor and all its descendants
Paraphyletic group
represents a group with some, but not all, of the descendants of an ancestor
Polyphyletic group
represents a group that does not include the most recent common ancestor
