Phylogenetic Tree / Evolutionary Tree Flashcards
- diagram that represents evolutionary relationships among organisms
- hypotheses, not definitive facts
phylogenetic tree
reflect how species or other groups evolved drom a series of common ancestors
pattern of branching
have a more recent common ancestor
more related
less recent common ancestor
less related
history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms
phylogeny
tips of lines where the species or groups of interest are found at
branches
branch point
internal node
internal node represents a __ event
divergence
divergence event
splitting apart of a single group into two descendant groups
what lies at each branch point
most recent common ancestor
inferred to be the oldest point in the tree and corresponds to the theoretical last common ancestor of all taxonomic units included in the tree
root of the phylogenetic tree
branch point that has three or more different species coming off of it
polytomy
what do scientist compare to generate phylogenetic trees
- external morphology
- internal anatomy
- behaviors
- biochemical pathways
- DNA and protein sequences
- characteristics of fossils
in building a tree, we organize species into nested groups based on shared __ __
derived traits
what are derived traits
traits different from those of the group’s ancestor
evolutionary trait that is homologous within groups of organisms that are all descended from a common ancestor in which the trait first evolved
ancestral traits
species that is more distantly related to the species of interest than they are to one another
outgroup
choose the tree that requires the fewest independent genetic events (appearances or disapperances of traits) to take place
parsimony
features that reflect shared ancestry
homologous features
features that are similar but arose independently
analogous features
how do analogous features arise
convergent evolution
tool that has revolutionized phylogenetic analysis
DNA sequencing
genes that are evolutionarily related
orthologous genes
groups that share an immediate common ancestor
sister taxa
development of organs or other bodily structures within different species, which resemble each other and have the same functions, but did not have a common ancestral origin
homoplasies
evolutionary change of features within a single lineage (species)
anagenesis
branching of lineage into two or more descendant lineages
cladogenesis
segement in tree which may split at an internal branch point or node
lineage/ branch
group of species that includes an ancestral species and all its descendants
clade/ monophyletic group
two clades that originate from a common ancestor
sister groups
root of the tree
most recent common ancestor (MRCA)
grouping consists of an ancestral species and SOME of its descendants
paraphyletic group
grouping consists of various species that LACK a common ancestor
polyphyletic group
character that originated in an ancestor of the taxon
shared ancestral character
- plesiomorphy
an evolutionary novelty unique to a particular clade
shared derived character
- apomorphy
two types of apomorphy
- autapomorphy
- synapomorphy
trait found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to the focal taxon
autapomorphy
derived trait shared by two or more groups
synapomorphy
assumes that the tree that requires the fewest evolutionary events is the most likely
maximum parsimony
