bio macroevolution (main idea 3)

what is gradualism?

small, gradual changes over time

what is punctuated equilibrium?

rapid changes over a short time

what is cladogenesis or divergent?

lineage split or branch resulting in genetic isolation

what is anagenesis or phyletic?

changes in allele frequencies and morphology accumulate

— unbranched line of descent

what is divergent evolution?

two related species evolve to be less similar

what does divergent evolution occur through? (+ example)

allopatric or sympatric

ex) homologous structures: all bones are the same and show they evolved from a common ancestor

what is convergent evolution?

when unrelated species occupy the same environment, they are subjected to selective pressures and have similar adaptations and similar body shape/structure

what is an example of convergent evolution?

analogous structures: mammals, fish, and birds are unrelated organisms but have similar body structures

what is parallel evolution?

two related species that are physically separated and through time have similar evolutionary adaptations because of similar evolutionary pressures (environment)

what is an example of parallel evolution?

marsupial mammals in australia and placental mammals in north america

what is coevolution?

two or more species affect each other’s evolution

what are examples of coevolution?

symbiotic relationships

— mutualism: pollinators and flowers

— predator and prey

— disease with a host (parasites)

— competitive species

what is adaptive radiation?

Rapid speciation with new species filling new niches, because they inherited successful adaptations. “Filling the available space”

burst of divergences gave rise to…

many new species and is common after mass extinctions

what are examples of adaptive radiation?

diversity of mammals, dinosaur extinction, finches on galapagos islands

what are background extinctions?

local changing conditions (normal extinctions of organisms), habitat destruction is the number one cause of loss of biodiversity