Chapter 5 Flashcards
What is a synapomorphy?
A derived and shared trait.
Aka HOMOLOGOUS.
What is an autapomorphy?
A derived trait that is not shared.
Aka HOMOPLASY.
What is a plesiomorphy?
An ancestral trait that is shared but not derived.
Aka ANCESTRAL.
What does parsimony refer to in phylogenetics?
The best phylogeny is the one with the fewest evolutionary changes.
What is a derived trait?
A trait that is different from the ancestor (new traits).
Example: A bat and a bird both have wings, but they have different common ancestors.
What is an ancestral trait?
A trait inherited from an ancestor.
What is long-branch attraction?
When two rapidly-evolving branches are incorrectly thought to be closely related.
What is sequence alignment?
Lining up homologous nucleotide positions to look for same or different bases.
What are distance methods in phylogenetics?
A tree where the distance between any two species equals the genetic distance between them.
What is maximum likelihood?
The probability of evolving a set of sequences given a phylogenetic tree and branch lengths.
What is an evolutionary model?
A mathematical representation used to describe how populations of organisms change over time.
What are Bayesian methods?
Given a model of evolution and a set of DNA sequences, it assesses the probability of a particular tree being correct.
What is an outgroup?
A more distantly related group of organisms used as a reference for determining evolutionary relationships.
What is bootstrap/Bayesian posterior probability?
It provides assessments of confidence for each clade of an observed tree based on bootstrap trees.
What are independent contrasts?
They summarize the amount of character change across each node in the tree.
