Population Ecology

Question 1

What is the definition of ecology?

Answer 1

the study of how organisms interact with one another and their environment

Question 2

Whats an environmental challenge?

Answer 2

Homeostasis

Question 3

homeostasis responses can be short term or long term. Describe both

Answer 3

short term: a few minutes to an individual’s lifetime

long term: natural selection can operate to make a population better adapted to the environment (evolution)

Question 4

Natural selection leads to evolutionary adaptions to environmental conditions. This is closely related to what?

Answer 4

species that are related that live in different environments and evolve differently.
ie: finches

Question 5

What is a population?

Answer 5

groups of individuals of the same place

Question 6

What are the three characteristics of population ecology?

Answer 6

1. ) population range, area throughout which a population occurs
2. ) pattern of spacing of individuals
3. ) How population changes in size through time

Question 7

Most species have limited geographic_____

Answer 7

range

Question 8

name three ways ranges change over time

Answer 8

1. ) environment changes
2. ) dispersal to new areas
3. ) humans have expanded and reduced ranges

Question 9

What is a metapopulation?

Answer 9

a network of distinct (physically distant) interacting populations

Question 10

Where do metpopulations occur?

Answer 10

occurs in areas in which suitable habitat is patchily distributed and is separated by intervening stretches of unsuitable habitat

Question 11

What is population demography?

Answer 11

the quantitative study of populations

-how populations size changes through time (whole populations or birth/death rates of a specific age)

Question 12

Population growth can be influenced by the population’s ______ ratio

Answer 12

sex

Question 13

the number of births is directly related to the number of ________

Answer 13

females

Question 14

What is Generation Time?

Answer 14

average interval between birth of an individual and birth of its offspring

Question 15

populations with short generations can (increase/decrease) in size more quickly than populations with long generations

Answer 15

increase

Question 16

True or False:

In general, larger organisms have longer generation times

Answer 16

true

Question 17

What is useful in making predictions?

Answer 17

linear regression

have a p-value

Question 18

What is Age Structure?

Answer 18

determined by the number of individuals in each different age group

Question 19

What is Cohert?

Answer 19

group of individuals of the same age

Question 20

What is Fecundity?

Answer 20

number of offspring produced in a standard time

Question 21

True or False:

Age structure has little influence on a population’s growth rate

Answer 21

false

it has a critical influence

Question 22

What is survivorship?

Answer 22

the percent of an original population that survives to a given age

Question 23

know how to sketch a graph

Question 24

Natural selection favors traits that maximize the number of surviving offspring left in the next generation. Two factors affect this quantity; what are they?

Answer 24

1. ) how long an individual lives

2. ) how many young it produces each year

Question 25

True or False: | the number of offspring produced is not as important as how many of those offspring themselves survive to reproduce

Answer 25

true

Question 26

Large offspring have a (greater/lesser) chance of survival while producing many small offspring may result in (high/low) survival rates

Answer 26

greater; low

Question 27

populations often remain the same size regardless of the number of offspring born. The equation used to calculate this would be....

Answer 27

r = (b-d) + (i-e) ``` r=rate of population increase b=birth rate d=death rate i=immigration e=emmigration ```

Question 28

What is biotic potential? | What is the equation used to calculate this?

Answer 28

When there are no limits on population growth dN/dt=riN N=number of individuals in the population dN/dt=the rate of change over time ri=the intrinsic rate of increase for the population

Question 29

the biotic potential of any population is _________ even when the rate of increase remains constant

Answer 29

exponential

Question 30

all populations eventually.........

Answer 30

reach some limit imposed by a shortage

Question 31

What is Carrying Capacity? | What letter represents it?

Answer 31

The maximum number of individuals that the environment can support K

Question 32

What equation is used to calculate logistic growth? (applies to populations as they reach K

Answer 32

dN/dt = rN (K-N)/K

Question 33

Density-dependent

Answer 33

factors that affect the population and depend on population size

Question 34

Density-independent

Answer 34

other factors, such as natural disasters, affect populations regardless of size

Question 35

Density Dependent: What is negative feedback? What is positive feedback?

Answer 35

negative: reduce population size positive: Allee effect; growth rates increase with population size

Question 36

Density independent effect rate of growth of a population is limited by something unrelated to the size of the population. What are some examples?

Answer 36

cold winters, droughts, storms, volcanic eruptions

Question 37

Animals like the North American snowshoe hare have 10-year cycles where population numbers fall and jump over a ten year period. There are two factors that effect this. What are they?

Answer 37

1. ) food availability | 2. ) predators

Question 38

K-Selected populations are adapted to thrive when.....

Answer 38

population is near its carrying capacity

Question 39

r-Selected populations: selection favors.....

Answer 39

individuals with the highest reproductive rates

Question 40

True or False: | most natural populations exist along a continuum of r and k selected traits

Answer 40

true

Question 41

Changes since the _______ allowed humans to escape_____

Answer 41

1700s; escape logistic growth

Question 42

human populations have grown exponentially - birth rates have____ - death rates has______

Answer 42

dropped | fallen dramatically

Question 43

True or False: Earth's rapidly growing human population constitutes as the smallest challenge to the future of the biosphere compared to other factors.

Answer 43

False the human population constitutes perhaps the greatest challenge to the future of the biosphere

Question 44

True or False: world population growth rate is in decline give figures to support answer

Answer 44

true high of 2% in 1965-1970 1.2% in 2008 however still an increase of 78 million people a year

Question 45

Name a reason why there may be a decline in population growth rate

Answer 45

- increased family planning efforts | - increased economic power and social status of woman

Question 46

What is an Ecological Footprint?

Answer 46

amount of productive land required to support an individual

Question 47

Look at graphs in the slide show; week 10

Answer 47

------