lecture 22

Question 1

what term do we use when resources are unlimited

Answer 1

rmax

Question 2

what is the formula for the exponential model

Answer 2

change in pop over change in time equals rmax times N

Question 3

when the population changes what stays constant

Answer 3

rmax

Question 4

more realistic population models limits growth by adding what

Answer 4

carrying capacity

Question 5

carrying capacity

Answer 5

maximum population size that the environment can support , population stops growing at this point

Question 6

what is the logistic growth model

Answer 6

exponential model plus carrying capacity term

Question 7

what is the logistic growth model equation

Answer 7

dN/dt=rmax*N[(k-n)/k] its the exponential growth model but adding k-n over k

Question 8

when N=0; then (k-N)/k is

Answer 8

1

Question 9

when N=K; then (k-N)/k is

Answer 9

0, this is when r reaches capacity

Question 10

in exponential growth the per capita growth rate

Answer 10

doesnt change even if pop gets super large

Question 11

in logistic growth the per capita growth rate

Answer 11

gets smaller as population gets closer to its max size

Question 12

what are the assumptions of the logistic model

Answer 12

1. no immigration or emigration 2. all individuals contribute equally 3. the environment thus K is constant

Question 13

what controls population size

Answer 13

biotic factors (parasites, disease, predation, etc) and abiotic factors that dont change based on the pop size and can change carrying capacity size

Question 14

positive density dependence

Answer 14

rare; when population growth is facilitated by the increased population density

Question 15

negative density dependence

Answer 15

common; when population growth is curtailed by crowding predators and competition

Question 16

r strategists

Answer 16

create large numbers of off spring without parental investment (type 3)

Question 17

why do r strategists occur

Answer 17

they occur in unstable changing environment and reproduce at rates approaching r max

Question 18

k strategists

Answer 18

few offspring with a lot of parental investment (type 1)

Question 19

why do k strategists occur

Answer 19

occurs in stable predictable environment and pop densities are often close to k carrying capacity

Question 20

BD model assumes what

Answer 20

assumes closed populations

Question 21

BIDE model

Answer 21

accounts for immigrants and emigrants in an open system

Question 22

metapopulations

Answer 22

they are made up of smaller populations that are linked by occasional movements among them; subpopulations can experience extinction and colonization events

Question 23

human population is approximated by what model

Answer 23

by the exponential model

Question 24

what is human population growth thanks to

Answer 24

vaccines, sanitation, and ANTIBIOTICS

Question 25

the human population is increasing but

Answer 25

the rate of change is decreasing

Question 26

what is global carrying capacity

Answer 26

1. some think maximum k is 9 to 10 billion 2. some think we have reached k because we are using non renewable resources 3. k may decline based on climate and ecosystem degradation