module 3

Question 1

vicariance

Answer 1

speciation genetic drift and adaptation caused by geographical barrier

Question 2

genetic drift

Answer 2

change in frequency of existing gene variant due to random chances.

some genes may disappear completely

Question 3

niche

Answer 3

the set of biotic and abiotic conditions into which the
species has evolved through natural selection (maximises fitness of individuals)
genotype/phenotype is a manifestation of this adaptation

Question 4

convergent evolution

Answer 4

occurs when organisms that aren’t closely related evolve similar features or behaviours, often as solutions to the same problems

Question 5

what happened when stickle back types were crossed.

two types include benthic (bottom) and limnetic (open water)

Answer 5

nothing wrong in terms of growth rate and fitness.

less fit however than parents of either type.

Question 6

how did collapsed speciation occur in the 1970s?

Answer 6

oxygen levels decreased

zooplankton density increased

zooplankton diversity decreased

nice space reduced

this meant food type became homogenised so there was no room for changing species.

Question 7

logistic growth curve

Answer 7

describes the growth of a population

Question 8

logistic growth equation

Answer 8

dN / dt = rN [ ( K-N ) / K ]

dN / dt - rate of change in this population

r - how many new individuals each individual contributes per time point.

N - population size

K - carrying capacity

Question 9

lotka-volterra model

Answer 9

2 species in competition for a shared, limiting resource

looks at the impact of one competing species to the other.

Question 10

zero net growth isocline

Answer 10

line between carrying capacities of each species on a graph.

at any point on this line, populations won’t grow anymore.

Question 11

resource partitioning

Answer 11

nice differences are a theoretical necessity for species coexistence

Question 12

character displacement

Answer 12

niche differences that emerge among phenotypically divergent populations can drive ecological speciation.

Question 13

measuring biodiversity
alpha diversity

Answer 13

measure the species composition at a small scale e.g. quadrat

Question 14

measuring biodiversity
beta diversity

Answer 14

measure of how much alpha diversity changes as you move from plot to plot.

Question 15

measuring biodiversity
gamma diversity

Answer 15

function of the alpha diversity and the gamma diversity.

describes composition over the large area of interest.

Question 16

chronosequencing

Answer 16

series of sites that occur along an age sequence

Question 17

what shows that limiting similarity is operating?

Answer 17

observed community is more diverse than random community.

Question 18

what shows an environmental filter is working?

Answer 18

observed community is more similar than random sample.