Population ecologists are primarily interested in understanding how biotic and abiotic factors influence the density distribution size and age structure of populations the overall vitality of a population of organisms ID: 467299
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0
Population EcologySlide2
Population ecologists are primarily interested in
understanding how biotic and abiotic factors
influence the density, distribution, size, and age structure of populations.
the overall vitality of a population of organisms.
how humans affect the size of wild populations of organisms.
studying interactions among populations of organisms that inhabit the same area.
how populations evolve as natural selection acts on heritable variations among individuals and changes in gene frequency.Slide3
Population ecologists are primarily interested in
understanding how biotic and abiotic factors
influence the density, distribution, size, and age structure of populations.
the overall vitality of a population of organisms.
how humans affect the size of wild populations of organisms.
studying interactions among populations of organisms that inhabit the same area.
how populations evolve as natural selection acts on heritable variations among individuals and changes in gene frequency.Slide4
Dispersion patterns tend to be highly dependent on the spatial scale of the observer. For example, football players lined up on the scrimmage line are clumped at the scale of 100 yards but uniformly dispersed at the scale of a meter. An example of animals that are likely to be clumped at a large scale but uniformly distributed at a small scale is
buffalo grazing on a prairie.
bluegills swimming in a northern lake.
ant nests in an abandoned field.
red-winged blackbirds in a cattail marsh.
all of the above.Slide5
Dispersion patterns tend to be highly dependent on the spatial scale of the observer. For example, football players lined up on the scrimmage line are clumped at the scale of 100 yards but uniformly dispersed at the scale of a meter. An example of animals that are likely to be clumped at a large scale but uniformly distributed at a small scale is
buffalo grazing on a prairie.
bluegills swimming in a northern lake.
ant nests in an abandoned field.
red-winged blackbirds in a cattail marsh.
all of the above.Slide6
Imagine that a species of fish used to be a broadcast spawner (producing many eggs that then get no subsequent parental care) but has evolved to be a mouth brooder (holding the eggs in the
parent’s
mouth
until they hatch and then caring for the young for a while). We would expect the survivorship curve of this species to
shift from Type I to
Type II or III.
shift from Type II to Type I.
shift from Type III to
Type I or II.
shift from Type II to
Type III.
vary unpredictably.Slide7
Imagine that a species of fish used to be a broadcast spawner (producing many eggs that then get no subsequent parental care) but has evolved to be a mouth brooder (holding the eggs in the
parent’s
mouth
until they hatch and then caring for the young for a while). We would expect the survivorship curve of this species to
shift from Type I to
Type II or III.
shift from Type II to Type I.
shift from Type III to
Type I or II.
shift from Type II to
Type III.
vary unpredictably.Slide8
The exponential growth model describes the increase in population size of a population that is not constrained by resources or space. The graph shows the elephant population in Kruger National Park, which appears to have been reproducing exponentially from 1900 to 1963. From this graph, you can tell that
none of the elephants died.
a female elephant living
around 1960 was more likely
to have a baby than a female
elephant living around 1920.
the elephants adapted to
the new park conditions
around 1955.
the vegetation the elephants
eat could support more than 5,000 elephants.
the more elephants there are, the more tourists will visit the park.Slide9
The exponential growth model describes the increase in population size of a population that is not constrained by resources or space. The graph shows the elephant population in Kruger National Park, which appears to have been reproducing exponentially from 1900 to 1963. From this graph, you can tell that
none of the elephants died.
a female elephant living
around 1960 was more likely
to have a baby than a female
elephant living around 1920.
the elephants adapted to
the new park conditions
around 1955.
the vegetation the elephants
eat could support more than 5,000 elephants.
the more elephants there are, the more tourists will visit the park.Slide10
You do a study on elephants and find that there are eight elephants per acre. This is a measurement of
density.
dispersal.
demographics.
survivorship.Slide11
You do a study on elephants and find that there are eight elephants per acre. This is a measurement of
density.
dispersal.
demographics.
survivorship.Slide12
A population of deer grows from 100 to 200 to 600, and when it gets to 600, it levels off. This population must have reached
exponential growth.
carrying capacity.
logistic growth.Slide13
A population of deer grows from 100 to 200 to 600, and when it gets to 600, it levels off. This population must have reached
exponential growth.
carrying capacity.
logistic growth.Slide14
Populations
adjust instantaneously to growth.
Populations
approach carrying capacity smoothly.
An
S-shaped growth curve results when
N
is plotted over time.
The
growth rate increases as
N
approaches K.
Which of the following statements is not an assumption of the logistic model of population growth
?Slide15
Populations
adjust instantaneously to growth.
Populations
approach carrying capacity smoothly.
An
S-shaped growth curve results when
N
is plotted over time.
The
growth rate increases as
N
approaches K.
Which of the following statements is not an assumption of the logistic model of population growth
?Slide16
Semelparous
organisms return to their place of birth to reproduce, but
iteroparous
organisms can reproduce anywhere.
Semelparous
refers only to plants, but
iteroparous
refers to animals.
Semelparous
organisms live after their first reproduction, but iteroparous organisms die. Semelparous organisms die after their first reproduction, but iteroparous organisms are
capable
of repeated reproduction.
What is the difference between
semelparity
and
iteroparity
?Slide17
Semelparous
organisms return to their place of birth to reproduce, but
iteroparous
organisms can reproduce anywhere.
Semelparous
refers only to plants, but
iteroparous
refers to animals.
Semelparous
organisms live after their first reproduction, but iteroparous organisms die. Semelparous organisms die after their first reproduction, but iteroparous organisms are capable of repeated reproduction.
What is the difference between
semelparity
and
iteroparity
?Slide18
10
100
0.5
3
6
Assume
U.S. energy use is 300 GJ per capita and Chinese energy use is 27 GJ per capita. If the U.S. population is 313 million people and the Chinese population is 1.3 billion people, the
total
U.S. energy use is approximately how many times greater than the
total
Chinese energy use
?Slide19
10
100
0.5
3
6
Assume
U.S. energy use is 300 GJ per capita and Chinese energy use is 27 GJ per capita. If the U.S. population is 313 million people and the Chinese population is 1.3 billion people, the
total
U.S. energy use is approximately how many times greater than the
total
Chinese energy use
?Slide20
In the logistic population growth model, the per capita rate of population increase approaches zero as the population size (
N
) approaches the carrying capacity (
K
), as shown in the table. Assume that
r
max
= 1.0 and
K
= 1,500. You can then calculate the population growth rate for four cases where population size (
N
) is greater than carrying capacity. To do this, use the equation for population growth rate in the table.
Scientific Skills ExerciseSlide21
N
= 1,510
N
= 1,600
N
= 1,750
N
=
2,000
Which population size has the highest growth rate
?Slide22
N
= 1,510
N
= 1,600
N
= 1,750
N
=
2,000
Which population size has the highest growth rate
?Slide23
If
r
max
is doubled, how would the population growth rates change?
The
population growth rates would be half of what they were.
The
population growth rates would double.
The
population growth rates would be unchanged.
The
population growth rates would be four times what they were.Slide24
If
r
max
is doubled, how would the population growth rates change?
The
population growth rates would be half of what they were.
The
population growth rates would double.
The
population growth rates would be unchanged.
The
population growth rates would be four times what they were.Slide25
What does a negative population growth rate tell you about the dynamics of the population?
The
birth rate equals the death rate.
The
population size is increasing instead of decreasing.
The
population size is decreasing instead of increasing.Slide26
What does a negative population growth rate tell you about the dynamics of the population?
The
birth rate equals the death rate.
The
population size is increasing instead of decreasing.
The
population size is decreasing instead of increasing.Slide27
The red line shows the growth
predicted
by the logistic model, and the black dots show the
measured
growth of the population. Does the measured growth match the predicted growth pattern
?
No
; only a few of the black dots sit on the red line.
Yes
; it matches at the beginning and at the end of the time range.
No
; it is lower than the
predicted
values in
some
parts and higher in
other
parts.
Yes
; it matches over the
whole time
range
.Slide28
The red line shows the growth
predicted
by the logistic model, and the black dots show the
measured
growth of the population. Does the measured growth match the predicted growth pattern
?
No
; only a few of the black dots sit on the red line.
Yes
; it matches at the beginning and at the end of the time range.
No
; it is lower than the
predicted
values in
some
parts and higher in
other
parts.
Yes
; it matches over the
whole time
range
.Slide29
What is the predicted carrying capacity of the
Daphnia
culture?
120
Daphnia
/50 mL
135
Daphnia
/50 mL
200
Daphnia
/50
mLSlide30
What is the predicted carrying capacity of the
Daphnia
culture?
120
Daphnia
/50 mL
135
Daphnia
/50 mL
200
Daphnia
/50
mLSlide31
Did the
Daphnia
population ever experience a negative growth rate
?
From
about day 70 to day 105, the population decreased in size, indicating a negative growth
rate
.
The
population never experienced a negative growth rate because it stabilized after 140 days and never went to zero.
From
about day 20 to day 50 and from day 100 to day 150, the population fell below the predicted values, indicating a negative growth rate
.Slide32
Did the
Daphnia
population ever experience a negative growth rate
?
From
about day 70 to day 105, the population decreased in size, indicating a negative growth rate.
The
population never experienced a negative growth rate because it stabilized after 140 days and never went to zero.
From
about day 20 to day 50 and from day 100 to day 150, the population fell below the predicted values, indicating a negative growth rate
.Slide33
What is the best biological explanation for why the
Daphnia
population growth rate became negative between days 70 and 105?
The
population’s data defined by the black dots have a slope that is negative during that period.
The
population grew larger than the predicted size during that period.
The
population overshot the carrying capacity
and
started running out of resources during that period.
The
population’s death rate was greater than the birth rate during that period
.Slide34
What is the best biological explanation for why the
Daphnia
population growth rate became negative between days 70 and 105?
The
population’s data defined by the black dots have a slope that is negative during that period.
The
population grew larger than the predicted size during that period.
The
population overshot the carrying capacity and started running out of resources during that period.
The
population’s death rate was greater than the birth rate during that period
.Slide35
Between days 100 and 160, the
Daphnia
population dropped below the predicted carrying capacity before rising back up to it. What is the best biological explanation for why the population stayed below the carrying capacity between days 100 and 160
?
The
predicted carrying capacity is incorrect. It really should be 120
Daphnia
/50 mL, where the population stabilized during those 60 days.
After
the population overshot the carrying capacity, the debris from dying
Daphnia
prevented the population from increasing until the debris decomposed, which took 60 days.
Overcrowding
before day 100 caused the birth rate to
decrease
and the death rate to increase, and it took another
60
days for the relative rates to stabilize.
Daphnia
decided to limit population growth until they figured out how large a population they could support in the culture, which took 60 days
.Slide36
Between days 100 and 160, the
Daphnia
population dropped below the predicted carrying capacity before rising back up to it. What is the best biological explanation for why the population stayed below the carrying capacity between days 100 and 160
?
The
predicted carrying capacity is incorrect. It really should be 120
Daphnia
/50 mL, where the population stabilized during those 60 days.
After
the population overshot the carrying capacity, the debris from dying
Daphnia
prevented the population from increasing until the debris decomposed, which took 60 days.
Overcrowding
before day 100 caused the birth rate to decrease and the death rate to increase, and it took another 60 days for the relative rates to stabilize.
Daphnia
decided to limit population growth until they figured out how large a population they could support in the culture, which took 60 days
.