Phylogeny Flashcards
Define Systematics
the study of the diversity of life
Microevolution
Changes in allele frequencies overtime
Speciation
Origin of new species
Macroevolution
Evolution of deeper groups (genus, family, class, order, etc.)
what is a node
a node represents a point where a branch splits = most recent (hypothetical) ancestor = speciation event
What is a “outgroup”
taxon that diverged before the taxa that are the focus of the phylogeny; helps to root the tree
what is “Polytomy”
a node that diverges into three or more branches, usually means not enough data to determine which taxa are most closely related
What are sister groups?
closely related taxa that share a recent common ancestor
to examine/measure a variety of traits in lots of taxa then calculate some measure of overall similarity among taxa based on those traits is called?
phenetics
to reconstruct evolutionary relationships by examining only certain traits – those assumed to be similar due to shared ancestry is called?
Cladistics
In cladistics, phylogenetic trees are also called ____
Cladogram
___ = monophyletic group = group of organisms that include common ancestor and all descendants
Clades
What are shared ancestral traits called?
Sympleisiomorphies
What are derived traits called?
Synapomorphies
Principle of Parsimony. definition.
simpler explanations/solutions are more likely to be true than complex ones.
