Population Ecology

Question 1

describes where individuals of a species might potentially be located.

(In the United states, most species have a range of 4-24 states.)

Answer 1

Geographic Range

Question 2

These species are an extreme, they are worldwide in distribution.

Answer 2

Cosmopolitan

Question 3

species found in only a small, restricted area, they represent the other side of the spectrum.

Answer 3

Endemic

Question 4

Factors Determining the Geographic Range of a Species

Answer 4

History
Biological Tolerances
Other Species
A combination of the above

Question 5

Why can’t palm trees present where winter temperatures regularly go below freezing?

Answer 5

The meristems are at the top of the trunk, not tolerant of freezing

Question 6

What other reasons explain why palm trees are near beaches and in micronenvironments?

Answer 6

They compete well in moist environments. Seeds are water dispersed.

Question 7

Many species have what is called a “Gondwanan” distribution. They occur in the Southern continents of Australia, South Africa, South America, and sometimes India.
These places are far away from each other now, but 150 million years ago, they were all linked together in a massive continent.

What is this an example of?

Answer 7

Historical Factors Determining Geographic Range

Question 8

Populations arise when….

Answer 8

Discontinuities in suitable habit for a species restricts the movement of individuals

Question 9

consequences of the way an organism interacts with the environment, and with other organisms, and influence its evolution

Answer 9

Emergent properties

Question 10

Simply the number of individuals in the population at any given time. Sometimes called abundance.

Answer 10

Size

Question 11

The number of individuals in the population per unit area or unit volume.
For many organisms this measure, rather than its actual numbers, exerts a real effect on the organism.

Answer 11

Density

Question 12

Patterns of Dispersion

Answer 12

Clumped
Regular
Random

Question 13

The most common pattern of dispersion, occurs because some areas of habitat are more suitable than others
ex:salamanders in numbers under fallen logs

Answer 13

Clumping

Question 14

Why do plants often clump?

Answer 14

Because seeds fall close to parent plant

Question 15

What are other reasons why a species may clump?

Answer 15

Safety of social reasons

Question 16

This pattern occurs in the absence of strong attraction or repulsion among individuals.
It is uncommon.

Answer 16

Random Distribution

Question 17

This generally happens because of interactions between individuals in the population, like competition, territoriality, and human intervention

Answer 17

Regular Distribution

Question 18

Creosote bushes in the Mojave desert are uniformly distributed because competition for water among the root systems of different plants prohibits the establishment of individuals that are too close to others.

Answer 18

Competition

Question 19

The desert lizard Uta sp. maintains somewhat regular distribution via fighting and territorial behavior

Answer 19

Territoriality

Question 20

I.e. ., the spacing of crops

Answer 20

Human Intervention

Question 21

This is the relative number of individuals at different ages

Answer 21

Age Structure

Question 22

is the proportion of individuals of each sex. The number of females is more important in the overall growth rate of populations
Examples: elk; fewer males of reproductive age than females; males breed with more than one female.

Answer 22

Sex Ratio

Question 23

differences among individuals in the population

Answer 23

Variability

Question 24

Most populations show differences among individuals.
Some variation has a genetic basis.
Other variation is largely environmental.
In many cases, variability is caused by both genes and the environment

Answer 24

Word

Question 25

Variability that occurs when the two sexes differ greatly in appearance

Answer 25

Sexual Dimorphism

Question 26

Variability that occurs when individuals differ in appearnace because of a dramatic transformation as they age

Answer 26

Metamorphisis

Question 27

Many organisms that exist as interwoven collections of subpopulations

Answer 27

metapopulations

Question 28

exhibit their own dynamics, with localized extinction, and recolonization of unoccupied areas of suitable habitat, determining their dynamics.

Answer 28

Metapopulations

Question 29

This is probably the best, simple, model of population growth…it predicts the rate of growth, or decay, of any population where the per capita rates of growth and death are constant over time

Answer 29

Exponential Growth

Question 30

Formula for exponential growth

Answer 30

Nf = Ni(e^rt)

Question 31

Can a population continue growing forever?

Answer 31

No, they would outstrip their resources

Question 32

this is the maximum number of individuals a given environment can sustain.

Answer 32

Carrying capacity

Question 33

Resources that are rare enough to inhibit a species' reproduction so that the population no longer grows. ex) light, water, nesting sites, prey, nutrients

Answer 33

Limiting Resources

Question 34

Factor limiting populations that intensifies as the size of a population increases

Answer 34

Density-Dependent Factor

Question 35

Examples of this factor that limits populations includes suitable nesting sites for birds, competition for light and water amongst prairie grasses

Answer 35

Density Dependent Factor

Question 36

Factors limiting populations that are independent of population size

Answer 36

Density-Independent Factors

Question 37

Examples of this factor that limits populations includes winter temperatures

Answer 37

Density-Independent Factors

Question 38

growth model that accounts for carrying capacity

Answer 38

Logistic growth model

Question 39

Formula for logistical growth model

Answer 39

dN/dt= rmax*N(K-N)/K NOTE: when k =n, dN/dT is equal to zero When it is small, growth rate is approximately rmax When N>K, population declines

Question 40

Does logistical growth model fit actual populations?

Answer 40

Only lab populations, not actual populations due to other factors like lag time.

Question 41

The time it takes between reaching carrying capacity and the slowdown in reproduction Rapidly growing populations, or populations with lag time often overshoot K, and exhibit population cycles, or chaotic behavior

Answer 41

Lag Time

Question 42

the study of the age structure and growth of populations. It is, essentially, the study of birth, reproduction, and death, as it relates to populations.

Answer 42

Demography

Question 43

was a famous early demographer/economist. In his Essay on the Principal of population, 1798, he was the first to reach the conclusion that human populations tended to grow until they outstripped their available food supply.

Answer 43

Thomas Malthus

Question 44

count every individual in the population

Answer 44

complete enumeration

Question 45

count individuals in many small portions of the area (e.g., quadrats) then calculate density mark and recapture index of relative abundance (e.g., pheremone baited insect traps, camera traps)

Answer 45

Sample the population

Question 46

A person’s chance of death

Answer 46

Life Tables

Question 47

a group of organisms born at the same time.

Answer 47

Cohort

Question 48

The variable that can estimate population growth or decline using life tables the sum of l(x)m(x) for the entire lifespan, estimates the number of female offspring produced per female.

Answer 48

R0

Question 49

R0>1, R0<0, R0=1

Answer 49

Increase, decline, stable

Question 50

traces the decline of a group of newborns over time.

Answer 50

Survivorship curves

Question 51

plot the probability of surviving to a certain age for a representative member of the population. They sometimes differ from male vs. female. Different populations might have different

Answer 51

Survivorship curves

Question 52

A convex curve. Most individuals live to adulthood with most mortality occurring during old age. I.e., humans, red deer, elephants.

Answer 52

Type I

Question 53

A straight line. An individual’s chance of dying is independent of its age. I.e., small birds and mammals.

Answer 53

Type II

Question 54

A concave curve, few individuals live to adulthood, with the chance of dying decreasing with age. I.e., oysters, redwood trees, snapping turtles.

Answer 54

Type III

Question 55

is the proportion of individuals at different ages. | It has a significant impact on future population growth.

Answer 55

Age distribution

Question 56

Populations that have remained constant for a long time have what type of age distributions?

Answer 56

Stable

Question 57

Rapidly growing populations have a disproportionate number of young individuals.

Answer 57

True

Question 58

many older people, fewer young people. Populations of some countries will decrease in the future.

Answer 58

Europeans and Japanese

Question 59

many young people, fewer old people populations will increase in the future.

Answer 59

Africa, Near east

Question 60

When is m(x), or age specific fecundity highest in humans?

Answer 60

20 yr olds.

Question 61

When are death rates highest?

Answer 61

Babies and old age.

Question 62

Are death rates in U.S. higher or lower than guatemala, mexico, and most of developing world?

Answer 62

Higher

Question 63

the timing of an organisms reproduction and death

Answer 63

Life history

Question 64

how many offspring an organism produces that are ultimately able to produce their own offspring.

Answer 64

Fitness

Question 65

Why is there a trade-off between survivorship and reproduction?

Answer 65

Reproduction is dangerous, involves resources for growth/maintenance

Question 66

Life histories have evolved to maximize an organisms expected fitness

Answer 66

Ya

Question 67

is one large reproductive effort (most insects, annual plants). Examples, grasshoppers, mayflies, octupi and squids Agave.

Answer 67

Semelparity

Question 68

is fewer offspring and many reproductive episodes. Example, perennial plants, most large mammals, sharks, most birds such as gulls and terns.

Answer 68

Iteroparity

Question 69

the number of offspring produced per reproductive episode.

Answer 69

Clutch size

Question 70

expend all their resources on a single clutch.

Answer 70

Semelparous organisms

Question 71

must save some resources for growth and survival.

Answer 71

Iteroparity

Question 72

Clutch size varies depending on...

Answer 72

Resource availability

Question 73

As an organism ages, it has more resources available to it. So more resources later means?

Answer 73

More offspring.

Question 74

Reproduce earlier means?

Answer 74

Less offspring.

Question 75

Larger organisms reach reproductive age faster or slower?

Answer 75

Slower

Question 76

an adaptation by which an organism may potentially increase the survivorship of its offspring. It comes at a cost to the parents, however, and results in fewer offspring because resources must be conserved

Answer 76

Parental Care

Question 77

Birds providing varying or similar amounts of parental care?

Answer 77

Varying.

Question 78

hatch and are able to fend for themselves immediately. Eggs are often laid in warm environments, and parents do not incubate them. In theory, this means more time to forage .

Answer 78

Superprecocial Birds

Question 79

such as passerines and parrots. Young are born blind and require constant parental care, after a period of egg incubation.

Answer 79

Superaltrical birds.