Lecture 10

Question 1

Which ones are the three life history classifications?

Answer 1

1. MacArthur and Wilson’s (r vs. K)
2. Grime’s (using plants)
3. Winemiller and Rose’s (using fishes)

Question 2

What is r?

Answer 2

Measure of population growth rate

Question 3

What does k represents?

Answer 3

Maximum sustainable population

Question 4

r selected

Answer 4

species are favoured for fast growth rates, often thought to be important in disturbed habitats

Question 5

K selected

Answer 5

species are likely to have traits that favour efficient utilization of resources, rather than maximizing
growth rates

Question 6

Which startegy selection may favour increases in growth rates?

Answer 6

R startegy

Question 7

Which startegy selection individuals that favour efficient use of resources, rather than maximizing resources?

Answer 7

K strategy

Question 8

How often do Semelparity reproduce?

Answer 8

Massive reproductive effort, once in a life.

Question 9

Examples of semelparity

Answer 9

Annual plants, pacific salmon

Question 10

How often of iteroparity reproduce?

Answer 10

Repeated episodes of reproduction

Question 11

Examples of iteroparity

Answer 11

Perennial plants, most mammals

Question 12

Semelparity favoured by

Answer 12

• low survival rate of adults between reproductive episodes
• high cost of surviving between reproductive episodes

Question 13

Iteroparity favoyred by:

Answer 13

High adult survival rates relative to juvenile survival rates

Question 14

Which of the following is most likely to be an r-selected species
A. Large marine mammal
B. Highly competitive mammal
C. Iteroparous bird that lays eggs
D. Small highly competitive bird
E. Insect that lives 3 months
F. Insect that lives that reproduces in the second year of life

Answer 14

E. Insect that lives 3 months

Question 15

Who developed the classification of plant life history strategies involving stress, competition, and disturbance?

Answer 15

Grime

Question 16

What are the two most important selective pressures in Grime’s classification of plant life history strategies?

Answer 16

Disturbance and abiotic stress

Question 17

What role does competition play in Grime’s plant life history strategies?

Answer 17

Competition is important but secondary to disturbance and abiotic stress

Question 18

What are the three life history strategies in Grime’s classification?

Answer 18

1. Stress-tolerant
2. Competitive
3. Ruderal

Question 19

What strategy describes plants that thrive in environments with high stress but low disturbance?

Answer 19

Stress-tolerant

Question 20

Which plant strategy is best suited for environments with abundant resources and low disturbance?

Answer 20

Competitive

Question 21

What strategy is best for plants in environments with frequent disturbance but lower stress?

Answer 21

Ruderal

Question 22

How does Grime define disturbance in plant life history strategies?

Answer 22

Disturbance refers to events or processes that limit plants by destroying plant biomass, causing a temporary change in environmental conditions that results in plant destruction or mortality

Question 23

What are some examples of disturbance in plant environments?

Answer 23

Severe storms, earthquakes, hurricanes, floods, and human activity

Question 24

How does Grime define stress in plant life history strategies?

Answer 24

Stress refers to external environmental constraints that limit the rate of dry matter production in plants, affecting all or part of the vegetation

Question 25

What are some examples of stress in plant environments?

Answer 25

Extreme conditions such as high or low temperatures, water availability (hydrologic conditions), light input, and nutrients

Question 26

What distinguishes disturbance from stress in plant environments?

Answer 26

Disturbance involves events that directly destroy or damage plant biomass, whereas stress refers to environmental conditions that limit plant growth without necessarily destroying biomass

Question 27

Which of the following is most likely to be a ruderal species A. Slow growing cactus that does not require much water B. Plant with long roots specialized in getting nutrients and water C. Plant that grows fast and shades other plants D. Evergreen tree that grows slow but is equipped to survive harsh winters E. Plant that produces many seeds early in life

Answer 27

E. Plant that produces many seeds early in life

Question 28

How is life history strategy in Winemiller and Rose's classification

Answer 28

Its based on trade- offs between - Juvenile survivorship - Fecundity - Age of reproductive maturity

Question 29

3 endpoints on the adaptive space surface

Answer 29

- Opportunistic - Equilibrium - Periodic

Question 30

How is an opportunistic in Winemiller and Rose's classification?

Answer 30

- Low juvenile survival - Low numbers of offspring, they continue to reproduce all year long - Early reproductive maturity

Question 31

How is an equilibrium in Winemiller and Rose's classification?

Answer 31

- High juvenile survival: they receive parental care - Low numbers of offspring - Late reproductive maturity, such as sharks, normally smaller

Question 32

How is an periodic in Winemiller and Rose's classification?

Answer 32

- Low juvenile survival - High numbers of offspring - Late reproductive maturity, ovesnt in their own growth

Question 33

Which of the following is most likely to be an equilibrium species A. The mola (fish) that produces 300 million eggs in one season B. The whale shark that produces large eggs and reaches maturity ~25 years C. The small stickleback that reaches maturity early D. Bottom feeding catostomid that produces small eggs and reproduces late in life

Answer 33

B. The whale shark that produces large eggs and reaches

Question 34

What traits do opportunistic species share with r-selection and ruderal species?

Answer 34

Opportunistic species tend to have traits like rapid growth, early reproduction, high reproductive output, and the ability to exploit temporary or disturbed environments

Question 35

Which life history strategy are equilibrium species similar to?

Answer 35

Equilibrium species tend to align with K-selection, characterized by slower growth, longer lifespans, and fewer offspring with higher parental investment

Question 36

Where do periodic species fall on the r-K spectrum?

Answer 36

Periodic species do not fit neatly into the r-K spectrum, as they have traits that differ from both r-selected and K-selected species, often involving reproduction patterns adapted to periodic disturbances or environmental cycles

Question 37

What are some traits of equilibrium species?

Answer 37

Equilibrium species typically have slower growth rates, longer lifespans, and invest more in fewer offspring with high survival potential, similar to K-selected species

Question 38

What defines periodic species in terms of their reproductive strategy?

Answer 38

Periodic species have reproductive strategies that are adapted to environments with periodic or predictable disturbances, but their life history traits don't strictly align with either r-selection or K-selection

Question 39

How would you alter a species management plan based on its life history classification?

Answer 39

Slow life histories are more at risk, low growth rate, mature late

Question 40

Loggerhead sea turtles are long-lived oceanic turtles that are currently classified as endangered. These turtles are iteroparous (but do not breed every year), mature late, lay many eggs and provide no parental care to their offspring. Which of the following statement BEST describes this species' life history. A. They are iteroparous so they are the perfect example of a K selected species. B. They are an example of an opportunistic species with a fast turnover rate or an r selected species. C. They could be described as a periodic species. D. Because of their late reproductive maturity they would definitely be an equilibrium species that could also be described as a K selected species

Answer 40

C. They could be described as a periodic species

Question 41

Loggerhead sea turtles are long-lived oceanic turtles that are currently classified as endangered. These turtles are iteroparous (but do not breed every year), mature late, lay many eggs and provide no parental care to their offspring. Because there are only limited resources available for conservation of the species, researchers need to decide how to best allocate conservation efforts. Given what you know about Life Histories, what life stage should you target conservation efforts on? A. Nesting sites for eggs B. Getting hatchlings from the beach to the ocean C. Avoiding by catch of subadults and adults in the ocean

Answer 41

C. Avoiding by catch of subadults and adults in the ocean

Question 42

Which of the following is most likely to be a ruderal species a. Slow growing cactus that does not require much water b.Plant with long roots specialized in getting nutrients and water c. Plant that grows fast and shades other plants d. Evergreen tree that grows slow but is equipped to survive harsh winters e. Plant that produces many seeds early in life

Answer 42

e. Plant that produces many seeds early in life