Macroevolutionary Patterns

Question 0

Tigger for adaptive evolution

Answer 0

1. New ecological opportunities (colonization do new habitat with few competitors and many resources/niches, mass extinction of competitors in current habitat that leaves extra resources/niches)
2. Morphological innovations/key adaptations

Question 1

Adaptive radiation

Answer 1

Rapid diversification into many descendant species that occupy a wide range of ecological niches

Question 2

Morphological innovations / key adaptations

Answer 2

Allow exploration of empty niches
Examples: jointed limbs = arthropod radiation, waxy cuticle/stomata = terrestrial plant radiation, flowers = angiosperm radiation, feeding on flowers = beetle radiation

Question 3

Adaptive radiation phylogenetic tree

Answer 3

Early branches short and lots of divergence rapidly, later branches longer and remain for longer time period

Question 4

Gradualism

Answer 4

Darwin 1859, gradual morphological change occurs within species, gradualism dominates history of species

Question 5

Punctuated equilibrium

Answer 5

Eldredge and Gould 1972, rapid morphological change occurs during speciation/divergence, stasis dominates history of species

Question 6

Stasis

Answer 6

No morphological change

Question 7

Mass extinction

Answer 7

Where largest % of species/families decreased and by how much, only 4% of extinction actually happen here, 5 major mass extinctions

Question 8

Stasis vs gradualism phylogenetic trees

Answer 8

Gradualism have slanted lines and stasis have straight horizontal and vertical lines (tree-like vs more cyber tree)

Question 9

Background extinction

Answer 9

Smaller extinction events, where 96% of extinction actually occurs

Question 10

The big 5

Answer 10

Big 5 mass extinctions

Question 11

K-T mass extinction

Answer 11

65 mya, 60-80% species. Extinct over next 500,000 years (meteor), no consistent body size effect (size not affect extinction), amphibians mammals crocodilians turtles and insects not affected, wiped out dinosaurs pterosaurs marine reptiles birds (except 1 order) plankton and many land plants

Question 12

Prone to extinction

Answer 12

Wider geographic range means less prone to extinction

Question 13

6th mass extinction

Answer 13

Human caused, recent world wide extinctions due to habitat loss, current extinction rate estimated 100-1000x background extinction rate