Chapter 12 Lecture 3 Flashcards Preview

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Flashcards in Chapter 12 Lecture 3 Deck (38)
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1

how do populations often grow

exponentially

2

for population growth, birth rates + immigration must be > than

the death rates+ emigration

3

what serves to regulate population growth

any factor that slows down the inputs relative to the outputs

4

factors that slow down the inputs relative to the outputs

predation, competition for scarce resources, herbivory, parasitism, disease, severe winter, drought

5

Raymond Pearl and L.J. Reed "On the Rate of Growth of the Population of the United States since 1790 and its Mathematical Representation"

Pop. growth in the U.S. declined - if the decline followed a regular pattern, it should be able to be described with a mathematical formula, and future population growth could be predicted

6

what did pearl and reed also reason

the rate of exponential
growth in the population would be related to population
size rather than time alone (since any time scale for any
population is arbitrary).

7

what did pearl and reed suggest

rather than using a
constant value for r which really represents unrestrained
population growth ---- r should decrease as N increases

8

rather than using a
constant value for r which really represents unrestrained
population growth ---- r should decrease as N increases according to the following relation:

dn/dt = rN
r = r0(1 - N/K)

9

r0

intrinsic rate of growth when its size is close to 0

10

K

carrying capacity of the environment, the max number of individuals that the environment can sustain indefinitely

11

r=

r0(1 - N/K)
or
r0 - r0N/K

12

r = r0 - r0N/K

defines a straight line with slope -r0/K

13

y

dependent

14

x

independent

15

m

slope

16

b

y intercept

17

N

independent variable

18

r

dependent variable

19

slope

-r0/K

20

logistic equation (equation for restrained growth

dN/dt = r0N(1 - N/K)

21

what shape is the logistic curve

hump-shaped

22

what is the rate of growth of the logistic curve at two population densities

(dN/dt) = 0
(when N = 0 and when K = N)

23

when does the peak of the hump occur

N = K/2 (1/2 to carrying capacity)

24

Carrying capacity (K):

the maximum population size that can be supported by the environment.

25

Logistic growth model

a growth model that describes slowing growth of populations at high densities

26

what is the logistic growth model represented by

dN/dt = rN(1-N/K)

27

S-shaped curve

the shape of the curve when a population is graphed over time using the logistic growth model

28

Inflection point

the point on a sigmoidal growth curve at which the population has its highest growth rate

29

early growth is

exponential

30

inflection point

the point of the fastest growth after which growth begins to slow