Chapter 9 Population Growth

Question 1

Per capita rates of birth and death

Answer 1

• constants for a population

- can be used to predict growth rate of the population regardless of N(t)

Question 2

Instantaneous per capita growth rate

Answer 2

(b-d)… prolly shoulld look through 174-175

Question 3

Exponential model of population growth

Answer 3

dN/dt = rN

Question 4

If r is greater than 0,

Answer 4

population size is increasing exponentially

Question 5

if r is 0

Answer 5

population size is contant

Question 6

if r is less than 0

Answer 6

populaation size is decreasing exponentially

Question 7

Cohort

Answer 7

group of individuals born in the same period of time

Question 8

Cohort life table vs Dynamic Composite Life Table vs Time-Specific Life Time

Answer 8

Cohort/dynamic life table: fate of a group of individuals is followed from birth to death

Dynamic composite life table: constructs a cohort born over several time periods instead of just one… like following a group from 1955, 1966, 1957

Time Specific Life Table: doesn’t involve a group but is constructed by sampling the population in some manner to obtain a distribution of age classes during a SINGLE time period

Question 9

lx calculation

Answer 9

survivorship: l2 = n2/n0

l5 = n5/n0

Question 10

qx calculation

Answer 10

age specific mortality rate
where d0 = n0-n1
q0: d0/n0

where d3 = n3-n2
q3: d3/n3

Question 11

Survivorship curve is based on what value? Mortality curve?

Answer 11

Survivorship = lx
mortality = qx

Question 12

3 Types of Survivorship curves

Answer 12

Type I: Human, high survivorship for a long time then hits a point drops fast to low survivorship

Type 2: Consistently decreasing survivorship… linear… common with birds and rodents

Type 3: Trees, quickly decreasing survivorship at the beginning, then evens out and steadily decreases after a point

Question 13

How to calculate sx

Answer 13

age specific survivorship rate:

1-qx

Question 14

Fecundity measurement on lifetables?

Answer 14

age specific birth rate… number of births per age

Question 15

Gross reproductive rate

Answer 15

Sum of all age specific birth rates of the population… sum up all the bx

Question 16

Ro

Answer 16

Net Reproductive Rate

-sum up all the lxbx values to come up with this! more accurate as it accounts of survivorship!

Question 17

If Ro is less than 1? Equal to 1? More than 1?

Answer 17

Less than one: not replacing selves, shrinking pop

Equal to one: replacing exactly themselves

More than one: more than replacing self, adding females

Question 18

Calculation of  (upside down y)

Answer 18

upside down y of t = 1 is N(1)/N(0)

upside down y of t = 5 is
N(5)/N(4)

Question 19

important concept

Answer 19

For r-Selection your B and D will both be very high, and for K-Selection both B and D will be low. However, both will result in a positive λ simply because it’s all about the ratios.

Question 20

Stable age distribution

Answer 20

when the PROPORTIONS of each age group in the population remain the same year after year… even while the population continues to increase

Question 21

Stationary age distribution

Answer 21

a special form of stable age distribution in
which the population has reached a constant
size with birth and death rates equal…. no more growth in population, and same proportions still!!!

Question 22

Relationship between r and lamda (upside down y)?

Answer 22

r = ln(lambda)

and

lambda = e^(r)