Quest 2 Flashcards
Phylogenetic systemics
classifying organisms based on evolutionary histories
phylogeny
branching relationships of populations as they give rise to descendants, allows us to reconstruct the tree of life
phylogram
trees with varying branch length
cladogram
trees with the same branch length
chronogram
tree where branch length represents actual time, not evolutionary change
polytomy
node with more than two branches arising from it
node
branch point where tree splits, represents common ancestors of the branching speces
branch
desendents
root
common ancestor to the whole tree, link to the rest of life
traits
specific values of a character
2 characters of a trait
- infer patterns of ancestry and descent
- can be mapped to infer evolutionary events
homologous trait
trait in two or more species that comes from a common ancestor
homoplasy
trait similar in two or more species even thought they do not share a common ancestor
analogous trait
trait in two or more species that evolved independently and do not share a common ancestor
homology vs analogy
homology is from a common ancestor, analogy is due to convergent evolution
divergent evolution
closely related populations diverge from one another due to different effects of natural selection
convergent evolution
where two or more populations become more similar to each other because they are exposed to similar selective conditions
characters
observable characteristics in an organism: anatomical, genetic, behavioral, deevelopmental
monophyletic group
taxonomic group including all descendants of the common ancestor and no other members
paraphyletic group
contains most common ancestor but not all descendents
polyphyletic group
an artificial clade, all descendants not from common ancestor
outgroup
group with no known evolutionary relationship to the focus taxon
DNA data
makes up and can reconstruct molecular phylogenies
long branch attraction
parsimony incorrectly inferring a too close relationship between branches
sister taxa
taxa derived from the same node
synapomorphy
shared derived trait
clade
group of species that share a single recent common ancestor
Carolous Linnaeus
worked with binomial nomenclature, put things together based on resemblance. named the most species
willi henning
phylogenetic systemics, groups based on evolutionary history
phytogeography
how a group or species moved across the globe over the course of evolutionary history
methods to create phylogenetic tree
- parsimony
- distance
- maximum likelihood
- Bayesian inference
parsimony method
trees that minimize the number of evolutionary changes
distance method
measure the distance of genetic distances to construct the tree
maximum likelihood method
how traits change through evolutionary processes by applying statistics
bayesian analysis method
like maximum likelihood with different interpretation of what is best explained
bootstrap resampling
continuously rerun data to verify information is correct
microevolutionary processes
migration and dispersal
macroevolutionary processes
radiations and speciation
heuristic search
explore possible solutions before deciding on one
transition
where a purine is replaced by another purine
transversion
when a purine is replaced by a pyrimidine or vice versa
polarity
whether a character trait is primitive or derived, the direction of evolutionary change
sequence alignment
arranging DNA sequences to find similarities due to evolutionary relatedness
tree score (parsimony score)
number of character changes on a tree
ingroup
group of organisms included in the cladogram
vestigial organs
organs in an organism that no longer function how they did in the ancestral form
