determining relatedness between species Flashcards
cladogram
a phylogenetic tree with unscaled branches
phylogram
a phylogenetic tree with scaled branches
polytomies
a node in a phylogenetic tree that shows more than 2 descendant lineages
what do polytomies indicate
either there isn’t enough information or adaptive radiation as occurred
monophyletic group
a group on a phylogenetic tree that includes a common ancestor and all descendants
paraphyletic group
a group that includes a common ancestor and some, but not all descendants
polyphyletic group
a group that does not include the common ancestor
another name for a monophyletic group
a clade
what is maximum parsimony
a principle that suggests that the simplest phylogenetic tree is most likely to be correct
phylogeny
the evolutionary history of lineages as they diverge over time
taxonomy
the science of classifying organisms based on their shared characteristics
conservative substitution
when an amino acid is substituted for another with biochemically similar properties
semi-conservative substitution
amino-acid replacement with similar shape but different biochemical properties
non-conservative substitution
amino-acid replacement with different properties and often leads to major changes in the protein
molecular clock
suggests that DNA mutates at a relatively constant rate over time, and uses this to calculate how long ago organisms diverged
