Evolutionary patterns from fossil record

Question 1

What is morphological disparity?

Answer 1

• A measure of how diverse morphology is
• E.g. Trilobites - morphological similarities changed over time, less similar in ordovician than early cambrian.

Question 2

What do origination patterns show us about evolutionary patterns in the fossil record?

Answer 2

• Do species originate through time in bursts or is it constant?
• Difficult to measure
• Needs to be measured over large areas to account for immigrations and emmigration

Question 3

What were the big 5 extinction events?

Answer 3

• End ordovician (short glacial event)
• End devonian (pulses due to aquatic anoxia)
• End permian (atmosphere pollution+heating)
• End triassic (atmosphere pollution+heating)
• KT (Bolide impact)

Question 4

Extinction patterns (including mass extinctions)

Answer 4

• Are extinction patterns constant or grouped in specific time.. ?
• Red queen hypothesis, Van valeen.
• Evolutionary arms race.
• Probability of going extinct remains constant.
• Fossil record incomplete (Signor-Lipps effect)\
• Steven J Gould - stochasticity. Random.
• Recovery can be rapid (adaptive radiation into the created vacuum) or protracted (cf. Lazarus Taxa and Elvis Taxa and the Lilliput Effect)

Question 5

What is taxonomic duration?

Answer 5

• How long a species lives for
• Fossil record shows patterns

Question 6

Fossils and biogeographic patterns

Answer 6

• Using cladograms to work out migration patterns
• Where an organism occurs through time

Question 7

What are Lazarus taxa?

Answer 7

Taxa gone up to the mass extinction events, disappear then come back

Question 8

What are Elvis taxa?

Answer 8

same as Lazarus taxa but later species are due to convergent evolution (not the same species, filled a niche)

Question 9

What is the Lilliput effect?

Answer 9

Small, takes time to diversify. Survivor taxa

Question 10

What is the debate between phyletic gradualism and punctuated equilibrium ?

Answer 10

• Darwin thought species evolved gradually over time
• Punctuated equilibrium - stasis, no change in the fossil record
• Small populations are isolated from large populations (with stasis)
• Small populations diversify quickly and become new species which increases in size.

Question 11

Terminology Gould used and what it means?

Answer 11

Species sorting
Fledgling species are more likely to survive if they are ecologically different from their parent species

Species selection
Species selection is the differential rates of appearance and extinction of species within lineages

Habitat tracking
Ecological communities follow habitats as they move during environmental change

Question 12

Red queen and court jester

Answer 12

• Red queen = evolution is driven by competition
• Court Jester - changes in environment drive evolution
• Mutually exclusive

Question 13

What are the hierarchial tiers of evolution as proposed by Gould?

Answer 13

1. Microevolutionary processes (e.g. competition): Evolutionary events n the ecological moment.
2. Punctuated events: Trends within lineages over geological time
3. Mass extinctions: Mass extinction