Evolution
a group of individuals of the same species living in the same location
population
term used for vertebrates with four limbs
tetrapods
DNA, proteins, and lipids are examples of these
molecular fossils
the simplest scenario requiring the fewest evolutionary steps is usually preferred
principle of parismony
transitional fossil between fish and tetrapods
tiktaalik
evolutionary processes can be thought of as having two distinct modes: _________ and _________.
microevolution/macroevolution
these are the closest living relatives of birds
crocodiles and alligators
any indirect evidence left by an organism, such as footprints, burrows, and fossilized feces
trace fossils
a point on a phylogenetic tree where exact branching order is unclear or unresolved
polytomy
character state similarity not due to common descent
homoplasy
these can serve as direct evidence of evolutionary history
fossils
phylogenetic reconstruction on the basis of synapomorphies
cladistics
a mold filled with sediment
cast
describe a shift in the function of a trait during evolution
exaptation (or preadaptation)
reversion back to an ancestral character state
evolutionary reversal
a reasoned hypothesis of the evolutionary relationships among organisms
phylogenetic tree
rotating these does not change the implied evolutionary relationship
nodes
a sedimentary rock formation that preserved the deep seafloor of 505 million years ago
Burgess Shale
a change of timing produces a sexually mature adult with juvenile features
paedomorphosis
what is the difference between phylogeny and phylogenetic trees?
a phylogeny is the evolutionary history of a lineage, and a phylogenetic tree is the visual representation of that history
changes in allele frequencies in a population over time
microevolution
what are the 8 taxonomic ranks, in order from most inclusive to least inclusive?
domain, kingdom, phylum, class, order, family, genus, species
alive 150 million years ago, this fossil is paleontology’s most famous example of a transitional form
Archaeopteryx
evolutionary change in form due to change in rate or timing of developmental events
heterochrony
what is the difference between characters and character states?
characters are identifiable heritable traits, and character states are the condition of the character ("present" or "absent")