Study Guide Exam 2

Question 1

What do life history traits represent?

Answer 1

The schedule of an organism’s life

Life history traits include aspects such as growth, reproduction, and survival strategies.

Question 2

What is parity?

Answer 2

The number of times an organism reproduces

Parity includes concepts such as semelparity (one-time reproduction) and iteroparity (multiple reproductions).

Question 3

What is fecundity?

Answer 3

The reproductive capacity of an organism

Fecundity refers to the potential number of offspring an organism can produce.

Question 4

Why do lifespans vary?

Answer 4

Due to factors such as species, environment, and life history traits

Lifespan variations can also be influenced by predation, resource availability, and reproductive strategies.

Question 5

How does parental investment contribute to life history traits?

Answer 5

It affects the survival and development of offspring

Higher parental investment often leads to fewer offspring but increased survival rates.

Question 6

What species have high parental investment?

Answer 6

Species like elephants, humans, and certain birds

These species typically invest significant time and resources in raising their young.

Question 7

What is the tradeoff between parental care and parental survival?

Answer 7

Increased parental care can lead to decreased parental survival

Investing heavily in offspring may expose parents to greater risks from predators or resource scarcity.

Question 8

What is the principle of allocation?

Answer 8

Resources are allocated to growth, reproduction, and survival

Organisms must balance these competing demands based on environmental conditions.

Question 9

Fill in the blank: Offspring size vs. _______.

Answer 9

Offspring number

Larger offspring may have better survival rates but fewer can be produced.

Question 10

What is a brood parasite?

Answer 10

An organism that relies on others to raise its young

Brood parasites often lay their eggs in the nests of other species.

Question 11

What are tradeoffs between growth and age at sexual maturity?

Answer 11

Faster growth may lead to earlier maturity but reduced size

This tradeoff can affect reproductive success and lifespan.

Question 12

What is the difference between indeterminate and determinate growth?

Answer 12

Indeterminate growth continues throughout life; determinate growth stops at maturity

Indeterminate growers can keep growing as long as resources are available.

Question 13

How do organisms differ in the number of times that they reproduce?

Answer 13

Some reproduce once (semelparity), others multiple times (iteroparity)

Differences in reproductive strategy can influence population dynamics.

Question 14

Do all organisms eventually become senescent?

Answer 14

Yes, senescence is a common feature of most organisms

Aging processes can vary significantly among species.

Question 15

What is semelparity?

Answer 15

Reproducing only once in a lifetime

Examples include certain species of salmon and insects.

Question 16

What is iteroparity?

Answer 16

Reproducing multiple times throughout life

Many mammals and birds exhibit this reproductive strategy.

Question 17

How have life history traits been impacted by climate change?

Answer 17

Altered reproductive timing, growth rates, and survival

Climate change can lead to mismatches in timing between species and their environments.

Question 18

How have life history traits been impacted by other environmental factors?

Answer 18

Factors like predation, resource supply, and climate affect growth and reproduction

These environmental pressures can shape evolutionary adaptations in species.

Question 19

Why does sexual selection favor traits that facilitate reproduction?

Answer 19

Sexual selection favors traits that enhance the chances of successful mating and reproduction.

Question 20

What is the difference between polygamy, polygyny, polyandry, and monogamy?

Answer 20

Polygamy: multiple partners; Polygyny: one male, multiple females; Polyandry: one female, multiple males; Monogamy: one male and one female.

Question 21

What are the advantages of sexual reproduction?

Answer 21

Genetic diversity and adaptability to changing environments.

Question 22

What are the disadvantages of sexual reproduction?

Answer 22

Energy expenditure and finding a mate.

Question 23

What are the advantages of asexual reproduction?

Answer 23

Quick population growth and no need for a mate.

Question 24

What are the disadvantages of asexual reproduction?

Answer 24

Lack of genetic diversity and vulnerability to environmental changes.

Question 25

Compare sex strategies in plants and animals.

Answer 25

Plants: often use pollination; Animals: utilize various mating systems.

Question 26

What are the different asexual methods of reproduction?

Answer 26

Budding, fragmentation, and binary fission.

Question 27

How can organisms evolve as separate sexes or as hermaphrodites?

Answer 27

Evolution can lead to specialization for reproduction efficiency and resource allocation.

Question 28

What factors influence sex ratios?

Answer 28

Environmental conditions, parental investment, and social structure.

Question 29

Can sex ratios be modified by natural selection?

Answer 29

Yes, natural selection can influence sex ratios based on reproductive success.

Question 30

What are the advantages of monogamous mating systems?

Answer 30

Increased parental investment and stability in offspring rearing.

Question 31

What are the advantages of polyamorous mating systems?

Answer 31

Increased genetic diversity and access to multiple resources.

Question 32

What is the benefit of having different mates?

Answer 32

Increased genetic variation and adaptability in offspring.

Question 33

What is ecological niche modeling?

Answer 33

Ecological niche modeling is a method used to predict the distribution of species based on environmental conditions.

Question 34

What are the five important characteristics of population distributions?

Answer 34

1. Density 2. Dispersion 3. Age structure 4. Sex ratio 5. Growth rate

Question 35

What are the types of surveys used to estimate population properties?

Answer 35

1. Complete counts 2. Sampling surveys 3. Mark-recapture surveys ## Footnote Each type is used based on the population size and accessibility.

Question 36

How are range and density impacted by abundance and body size?

Answer 36

Range and density are influenced by the abundance of individuals and their body size, affecting resource availability and habitat use.

Question 37

Why is dispersal essential to colonizing new areas?

Answer 37

Dispersal allows populations to spread to new habitats, reducing competition and increasing genetic diversity.

Question 38

What are factors leading to patchy distributions of populations?

Answer 38

Factors include habitat fragmentation, resource availability, and environmental conditions.

Question 39

What are the different measures of dispersion?

Answer 39

1. Variance 2. Standard deviation 3. Range 4. Quartiles

Question 40

What are density independent and density dependent factors?

Answer 40

Density independent factors affect populations regardless of size, while density dependent factors have effects that vary with population size.

Question 41

What is Logistic growth?

Answer 41

Logistic growth is a model where population growth slows as it approaches carrying capacity.

Question 42

What is Geometric Growth?

Answer 42

Geometric growth is a model of population increase where the population grows by a constant proportion at each time period.

Question 43

What is Exponential Growth?

Answer 43

Exponential growth is a model where the population increases continuously at a constant rate.

Question 44

What is the relationship between λ and r?

Answer 44

λ (lambda) is the finite rate of increase, while r is the intrinsic rate of increase; they are related through the equation r = ln(λ).

Question 45

What is an inflection point?

Answer 45

An inflection point is where the growth rate of a population changes direction, often indicating a shift in growth dynamics.

Question 46

What is carrying capacity?

Answer 46

Carrying capacity is the maximum population size that an environment can sustain indefinitely.

Question 47

How and why do populations fluctuate naturally over time?

Answer 47

Populations fluctuate due to factors like resource availability, predation, and environmental changes.

Question 48

What is an overshoot?

Answer 48

An overshoot occurs when a population exceeds its carrying capacity, leading to resource depletion.

Question 49

What is a die-off?

Answer 49

A die-off is a rapid decrease in population size, often following an overshoot.

Question 50

Why do chance events cause small populations to go extinct?

Answer 50

Chance events can have a larger impact on small populations, leading to loss of genetic diversity and increased vulnerability.

Question 51

What are stochastic events?

Answer 51

Stochastic events are random occurrences that can affect population dynamics, such as natural disasters.

Question 52

What is delayed density dependence?

Answer 52

Delayed density dependence refers to the lag in population response to changes in density, causing cyclic population patterns.

Question 53

What are metapopulations?

Answer 53

Metapopulations are groups of spatially separated populations that interact through immigration and emigration.

Question 54

What is the source-sink population model?

Answer 54

The source-sink model describes how some populations (sources) provide individuals to others (sinks) that cannot sustain themselves.

Question 55

Why are metapopulations important for conservation?

Answer 55

Metapopulations enhance genetic diversity and resilience, crucial for species survival, exemplified by the ferret conservation efforts.

Question 56

What would make a metapopulation stable?

Answer 56

A stable metapopulation has balanced immigration and emigration rates, ensuring persistence of subpopulations.