EE Lecture 37: Biodiversity Models

Question 1

give equation for species area relationship and then log

what is z often around

Answer 1

S = cA^z

logS = k + zlogA
z often around 0.25

Question 2

what does species area relationship hypothesize

Answer 2

more species found in larger areas

more isolated areas often have fewer species than expected from their area

Question 3

what processes can species area relationships be explained by

Answer 3

neutral or niche based processes

Question 4

when is multiple regression not suitable

Answer 4

when variables are strongly associated

Question 5

how does isolation affect species number

Answer 5

more isolated areas often have fewer species than expected

Question 6

what is the eqbm theory of island biogeogrAPHY

Answer 6

Larger and less isolated (nearer) islands have more species, as near islands have more immigration and large islands have a greater rate of immigration and less extinction

Question 7

what is the eqbm number of an island

Answer 7

number of species at which immigration and extinction balance

Question 8

why do larger islands have lower extinction rates

Answer 8

as they can support larger popns and are also larger targets so have more immigration

Question 9

why do larger islands have more immigration

Answer 9

theyre larger targets

Question 10

whats along the acis of an eqbm theory graph

Answer 10

x - no. species on island

y - eate of extinction or immigration

Question 11

what is a neutral theory

Answer 11

species’ fates are independent of their traits or niches

Question 12

why are eqbm theory predictions qualitive

Answer 12

doesnt explain z ~ 0.25 unless you make extra assumptions

Question 13

in what way is eqbm theory of island biogeography dynamic

Answer 13

theres turnover

Question 14

give some alternative explanations to eqbm theory

Answer 14

they are based on niches

larger areas have more niches/habitats

Question 15

what theory did Stephen Hubbell develop

Answer 15

the neutral theory of biodiversity

Question 16

what did the neutral theory of biodiversity involve

Answer 16

random mortality opens a gap for colonisation
biodiversity is thus down to chance (opposing the niche theory)
No ecological differences among species

Question 17

give a name of a theory that opposes the niche theory

Answer 17

the neutral theory

Question 18

what is the niche theory

Answer 18

ecological differences between species enable them to coexise (ghost of competitions past)

Question 19

give some examples of ecological differences

Answer 19

environmental heterogeneity, relief, soil type, rainfall

Question 20

what is the traditional explanation for coexistence and richness

Answer 20

niche theory

Question 21

what happens in the neutral theory of biodiversity

Answer 21

species abundances fluctuate by drift (like alleles)
overtime species dwindle to 0 abundance by chance
if there’s immigration, can introduce new species
diversity is a balance between immigration and extinction

Question 22

what does SAR relationship need to be like to predict species extinction rate

Answer 22

if SAR is in eqbm, can use it to predict species extinction rate

Question 23

what does SAR need to be like to predict diversification

Answer 23

eqbm

Question 24

what is the most widespread patters in biodiversity

Answer 24

SAR

Question 25

if equilibrium explanations are right, what can SAR make predictions about

Answer 25

conservation and macroevolution