Flashcards in Chapter 12 Lecture 1 Deck (67)

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1

## under ideal conditions...

### populations can grow rapidly

2

## demography

### the study of populations

3

## growth rate

### in a population, the number of new individuals that are produced per unit of time minus the number of individuals that die

4

## Intrinsic growth rate (r)

### the highest possible per capita growth rate for a population.

5

## what do individuals experience under ideal conditions

### maximum r (i.e., maximum reproductive rates and minimum death rates

6

## what does the strength of a reproductive population depend on

###
1. the number of individuals of reproductive age

2. the availability of resources such as food and mates

3. the presence or absence of predators, disease, etc.

7

## how may individuals be added to populations

###
1. continuous reproduction

2. discrete reproductive periods

8

## what does the periodicity with which offspring are produced result in

### important differences in the way in which population growth is conceptualized mathematically

9

## in many species, young are added only during certain times of the year during...

### discrete reproductive periods - such populations undergo geometric growth

10

## in geometric growth

### the rate of increase is proportional to the number of individuals present in the population at the beginning of the discrete reproductive period

11

## what is the typical form of population growth in the wild

### geometric growth

12

## species that reproduce continually

### they can add young at any time of the year

13

## what do populations with continual reproduction undergo

### exponential growth

14

## exponential growth model

### a model of population growth in which the population increases continuously at an exponential rate

15

## what equation describes the exponential growth model

### Nt+ N0e^rt

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## Nt

### future population size

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## N0

### current population size

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## r

### intrinsic growth rate

19

## t

### time over which a population grows

20

## e

### 2.7183

21

## J-shaped curve

### the shape of the exponential growth when graphed

22

## the rate of a population's growth at any point in time is the derivative of this equation

### dN/dt = rN

23

## e^r

### the factor by which the population increases during each unit of time, and is sometimes symbolized with a lambda

24

## exponential growth

### results in a continuous curve of increase (or decrease, when the rt term is negative) whose slope varies in direct relation to the size of the population

25

## the rate of increase of a population undergoing exponential growth at a particular instant in time, the instantaneous rate of increase =

### dN/dt = rN

26

##
dN/dt = rN

this equation encompasses two principles (A)

### 1. the exponential growth rate (r) expresses the population increase (or decrease) on a per individual basis

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##
dN/dt = rN

this equation encompasses two principles (B)

### 2. the rate of increase (dN/dt) varies in direct proportion to the size of the population (N)

28

## the rate of the change in population size equals

### the contribution of each individual to population growth times the number of individuals in the population

29

## the individual contribution (per capita) to population growth is the difference between

### the birth rate (b) and the death rate (d) calculated on a per capita basis

30