lecture 16: macroevolution Flashcards
(22 cards)
microevolution
evolution occurring within populations, including adaptive and neutral changes in allele frequencies from one generation to the next
macroevolution
evolution occurring about the species level, including the origination, diversification and extinction of species over long periods of evolutionary time
turnover
how species diversity changes through time
alpha
rate at which new species originate
omega
rate at which species go extinct
biogeography
study of distribution of species across space and time
dispersal
movement of populations from one geographic region to the other
vicariance
formation of geographic barriers to dispersal and gene flow, resulting in separation of populations
limitations of measuring diversity through time
only have what is found and available
species concepts based on fossils
gaps in fossil records
geological changes in land masses
lazarus taxa
taxa appear to be extinct but show up later
elvis taxa
incorrect taxonomic assignments
zombie taxa
taxa get moved because of sediments moving
methods to minimize limitations
subdivide groups based on habitats, taxonomy
adaptive radiations
evolutionary lineages that have undergone exceptionally rapid diversification into a variety of lifestyles or ecological niches. alpha> omega
mechanisms of adaptive radiations
environmental change, dispersal to island/ water body, extinction, new adaptations
background extinction
normal rate of extinction for a taxon
mass extinction
statistically significant departure from background extinction rates that result in a substantial loss of taxonomic diversity
ordovician event
sea level fluctuations
devonian event
global cooling followed by warming
permian event
siberian volcanism, global warming, ocean acidification
triassic event
volcanic activity increased CO2 levels and global temps
