Exam 2 Study Guide Flashcards
(182 cards)
Common lineage from which all taxa are descended (indicated at the base of the tree)
Rooted
No common lineage.
Root direction of time unspecified
Unrooted
Most recent common ancestor (shown with a dot/point)
Interior nodes
An ancestral tax on and all of its descendants
Monophyletic group/Clare
Used as a root for a phylogenetic tree. It’s evolutionary relationship to tax on being studied is already known
Out group
A diagram to show inferred evolutionary relationship to a shared common ancestors
Phylogenetic tree
A group that includes the ancestor and all of the descendants (also known as a clade)
Monophyly
A group that includes the common ancestor of all its members but does not contain every species that descended from that ancestor
Paraphyly
A group characterized by one or more homoplasies, they have evolved separately but gained one or more similar traits
Polyphyly
Any observable feature, or trait of an organism whether acquired or inherited
Character
Finite number of states (ex: number of vertebrate; nucleotide sequence
Discrete
Infinite number of states (ex: height and length
Continuous
Particular version of a character (ex: straight curly)
Character state
When are character states informative
If they are shared (homologous) and derived
A trait shared by two or more species because those species have inherited the trait from a shared common ancestor
Homologous trait
A trait that has changed form or state from the ancestral from over evolutionary
Derived trait
An approach to selecting the best phylogenetic tree given some set of character data. _ methods assume that the best tree is the only one that requires the fewest character changes to explain the data (but remember _ is not the only criterion for creating phylogenetic trees)
Parsimony
A trait that is similar in two species, but NOT due to common ancestry poses a problem because it can be misleading trying to reconstruct an evolutionary tree results in wrong conclusions
Homoplasy
Lost three evolutionary sources of homoplasy
Convergent evolution
Parallel evolution
Evolutionary reversal
An inherited trait reverting back to an earlier form over the course of many generations
Evolutionary reversal
Species develop similar traits because they share a similar way of life (not a common ancestor)
Convergent Evolution
The independent evolution of similar traits, starting from a similar ancestral condition
Parallel evolution
A trait that is similar in two different species or taxa, not because of common descent, but rather as a result of natural selection operating in similar ways along appear ate evolutionary lineages
Analogous trait
The us of comparisons of sets of species to test hypotheses about evolution
Comparative method