EE25

Question 1

what 6 things are related to population ecology?

Answer 1

1) Economics (lynx/harefur trade and fishing)
2) Politics and world peace (fishing and how many people earth can support)
3) immunology (you can study interacting pop dynamics of the virus and antibodies that fight it)
4) Pest outbreaks (also related to harvesting and economics e.g locusts)
5) epidimiology (malaria)
6) herd immunology (you cannot vaccinate everyone, maths models show 80-90% vaccination efficient WHO eradicated smallpox)

Question 2

what are the basic things studied in population ecology?

Answer 2

1) population numbers
2) how/why numbers change
3) how do populations interact with each other and the environment

Question 3

what is the fundamental equation of population dynamics?

Answer 3

N1 = N0 + B - D + I - E

Question 4

what is population growth?

Answer 4

B - D + I - E

Question 5

model of population growth

Answer 5

dN/dt = r N

Question 6

what is dN/dt

Answer 6

the rate of change of N

Question 7

what is r?

Answer 7

average number of surviving offspring each individual has = intrinsic rate of increase

Question 8

if r is positive what kind of growth is the population undergoing?

Answer 8

exponential

Question 9

what examples are there in nature of exponential growth? (2)

Answer 9

1) yeast in lab

2) human population growth (super exponential)

Question 10

is exponential growth the norm?

Answer 10

No. but Newton’s first law (forces are balanced) also seems to be an exception wrt population growth

Question 11

What are limiting factors and give 5 examples.

Answer 11

limiting factors stop populations increasing exponentially by decreasing the growth rate.

1) weather and environmental variation
2) lack of food/nutrients/water
3) lack of space/light
4) spread of disease and parasites
5) predation

Question 12

what are regulating factors a subset of?

Answer 12

limiting factors

Question 13

what are regulating factors?

Answer 13

factors that bring the population back to equilibrium. Allows populations to persist.

Question 14

what do regulating factors do?

Answer 14

allow populations to persist by limiting population growth rate when populations are large ie food limitation but also allows populations to recover when rare.

Question 15

what factors are difficult to show in nature?

Answer 15

regulating factors

Question 16

what is population equilibrium?

Answer 16

when the population size is not increasing or decreasing over time. Idealized as a constant population size.

Question 17

what is K?

Answer 17

carrying capacity

Question 18

In what way must limiting factors act to regulate populations?

Answer 18

in a density dependent manner

Question 19

what are the main component processes that change number of individuals in a population?

Answer 19

Births,Deaths,Emmigration,Immigration

Question 20

what is r?

Answer 20

intrinisic rate of increase

Question 21

what is fecundity?

Answer 21

he actual reproductive rate of an organism or population, measured by the number of gametes (eggs), seed set, or asexual propagules.

Question 22

what are the “vital” rates?

Answer 22

birth + death

Question 23

How often does the lynx/hare cycle last?

Answer 23

populations fluctuate over 9-10 year cycles

Question 24

is the snowshoe hare the primary food source for the lynx?

Answer 24

yes

Question 25

what is the max amount of hares per km? After 8-11 years what happens?

Answer 25

up to 1500 per km (but after 8-11 years habitat cannot support; predation and starvation will set in)

Question 26

what records were made of the snowshoe hare/lynx populations?

Answer 26

Hudson bay trapping records over 100 years

Question 27

what is the maximum sustainable yield ?

Answer 27

the maximum level at which a natural resource can be routinely exploited without long-term deplition

Question 28

what is the optimum sustainable yield?

Answer 28

the LOE (level of effort) that maximizes the difference between total revenue and total cost (where marginal revenue=marginal cost)

Question 29

why do puruvian anchovies do well?

Answer 29

it is a zooplankton feeder whereas most fish of economic importance feed on other fish

Question 30

what has the WHO already eradicated and what are they in the process of eradicating?

Answer 30

smallpox, eradicating polio

Question 31

can you vaccinate everyone? what % vaccination is efficient?

Answer 31

no and mathematical models show 80-90% vaccination is efficient