Tanentzap

Question 1

Pre-zygotic barriers =

Answer 1

no offspring

Question 2

Post-zygotic barriers =

Answer 2

no grandoffspring

Question 3

speciation without selection

Answer 3

drift
founder effects
hybridisation
mutation 
physical or biotic barriers

Question 4

Components of ecological speciation

Answer 4

divergent selection
RI
Link between RI and selection

Question 5

Sources of divergent selection

Answer 5

Differences in response to abiotic environmment (innovations, niche discordance)

Biotic interactions
(competition –> character displacement)
(Co-evolution –> escape and radiate)
(reinforcement of pre-zygotic barriers)

Sexual selection

Question 6

Forms of RI

Answer 6

Prezygotic - Habitat isolation, sexual isolation

Postzygotic - Hybrid inviability

Question 7

Mechanisms linking ecological and reproductive traits

Answer 7

Pleiotropy (magic traits) eg. differential flowering time

Linkage disequilibrium

Question 8

Modes of geographic speciation

Answer 8

allopatric (different regions) – most common
sympatric (Same geographic region)
parapatric (different habitats but connected)

Question 9

Spacial scale influences on speciation rate

Answer 9

Species that are larger + can disperse further need larger islands to speciate

Question 10

Species-pump

Answer 10

Allopatry –> secondary sympatry

Produces hyper-diverse genera

Question 11

Applications of variation

Answer 11

Variation reduces extinction risk (lower variation linked to low population size + isolation). 77% of threatened species less diverse than non-threatened relatives (correlation not cause?).

Variation increases resilience to climate variability

Question 12

Applications of selection

Answer 12

Increase fisheries yield by harvesting smaller fish. Drives selection for fast growth rates.