Chapter 9 Population Growth Flashcards Preview

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Flashcards in Chapter 9 Population Growth Deck (22)
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1
Q

Per capita rates of birth and death

A
  • constants for a population

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

2
Q

Instantaneous per capita growth rate

A

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

3
Q

Exponential model of population growth

A

dN/dt = rN

4
Q

If r is greater than 0,

A

population size is increasing exponentially

5
Q

if r is 0

A

population size is contant

6
Q

if r is less than 0

A

populaation size is decreasing exponentially

7
Q

Cohort

A

group of individuals born in the same period of time

8
Q

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

A

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

9
Q

lx calculation

A

survivorship: l2 = n2/n0

l5 = n5/n0

10
Q

qx calculation

A

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

where d3 = n3-n2
q3: d3/n3

11
Q

Survivorship curve is based on what value? Mortality curve?

A
Survivorship = lx
mortality = qx
12
Q

3 Types of Survivorship curves

A

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

13
Q

How to calculate sx

A

age specific survivorship rate:

1-qx

14
Q

Fecundity measurement on lifetables?

A

age specific birth rate… number of births per age

15
Q

Gross reproductive rate

A

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

16
Q

Ro

A

Net Reproductive Rate

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

17
Q

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

A

Less than one: not replacing selves, shrinking pop

Equal to one: replacing exactly themselves

More than one: more than replacing self, adding females

18
Q

Calculation of  (upside down y)

A

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

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

19
Q

important concept

A

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.

20
Q

Stable age distribution

A

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

21
Q

Stationary age distribution

A

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!!!

22
Q

Relationship between r and lamda (upside down y)?

A

r = ln(lambda)

and

lambda = e^(r)