Life Histories

Question 1

What are the three life history traits?

Answer 1

• Growth and development
• Survival
• Reproduction

Question 2

phenotypic plasticity

Answer 2

same genotype can look different depending on the environmental conditions

Question 3

Holometabolous animals

Answer 3

complete change in metamophorsis from being born to adult form

Question 4

Hemimetabolous organisms

Answer 4

similar metamophorsis throuought life

Question 5

Determinate growth

Answer 5

an individual does not grow any more once it reaches sexual maturity reproduction (eg:most species of birds and mammals)

Question 6

Indeterminate growth

Answer 6

an individual continues to grow after it initiates reproduction (eg:many species of plants, invertebrates, fishes, reptiles, and amphibians)

Question 7

what type of distribution does survival have?

Answer 7

binominal (you live or you die)

Question 8

Survival rate

Answer 8

proportion of individuals in a group still alive at a given time

Question 9

Longevity

Answer 9

life span of an organism

Question 10

Senescense

Answer 10

a gradual decrease in fitness with age (decrease fecundity and survival)

Question 11

Fecundity

Answer 11

number of offspring per capita in a given time interval (for example per reproductive episode)

Question 12

Parity

Answer 12

number of reproductive episodes

Question 13

Semelparous organisms

Answer 13

single reproductive cycle before death (eg: salmon)

Question 14

Iteroparous organisms

Answer 14

multiple reproductive cycles (eg: humans)

Question 15

Seasonal breeders

Answer 15

set time of the year during which mating occurs and new offspring are generated (eg: bluetits)

Question 16

Non-seasonal breeders

Answer 16

can reproduce year-around (eg: rabbits)

Question 17

when does reproduction start and end?

Answer 17

• Age of first breeding
• Menopause

Question 18

how can climate affect reproduction?

Answer 18

with turtles, as precipitation decreases due to climate change the temporal trend in hatching success decreased

Question 19

Principle of allocation

Answer 19

the same time, energy and nutrients cannot be used for multiple purposes (eg: grow your own body vs have a baby vs outrun a predator)

Question 20

what are classic examples of trade-offs?

Answer 20

• Number vs size of offspring
• Number of offspring vs per capita parental care
• Parental care vs parent survival
• Longevity vs reproductive onset

Question 21

population

Answer 21

Individuals of one species living in a particular area

Question 22

what are the main characteristics of a population?

Answer 22

• geographic distribution
• abundance
• density
• dispersion
• dispersal

Question 23

what is geographic distribution?

Answer 23

the area occupied by the population

Question 24

endemic distribution

Answer 24

species that live in a single, often isolated, location

Question 25

cosmopolitan distribution

Answer 25

species with very large geographic ranges that can span several continents

Question 26

what factors determine geographic distribution?

Answer 26

- ecological suitability (eg: environmental conditions, species interactions) - geographic barriers - human impacts and introductions

Question 27

Fundamental niche

Answer 27

range of abiotic conditions under which a population/species can persist

Question 28

Realized niche

Answer 28

the range of abiotic conditions under which populations of a population/species actually occur

Question 29

abundance

Answer 29

The total number of individuals in a population that exist within a defined area

Question 30

why are changes in abundance problematic?

Answer 30

- Declines may lead to extinction, loss of ecological function - Increases may lead to out-competition, range expansion

Question 31

density

Answer 31

The number of individuals per space unit

Question 32

how are variations in density influenced amoung species?

Answer 32

- Body mass - Diet - Brain size

Question 33

dispersion

Answer 33

The spacing of individuals with respect to one another within the distribution

Question 34

what are types of dispersion?

Answer 34

- Clustered or clumped (most common) - Even, uniform or regular - Random (rarest)

Question 35

dispersal

Answer 35

The movement of individuals from one area to another with unlikely return (different from migration)

Question 36

what are the types of dispersal (how)?

Answer 36

- active eg: organism decide direction (wolf) -passive eg: organism does not decide (wind-dispersed seed, fish larvae)

Question 37

what are the types of dispersal (who)?

Answer 37

- Natal dispersal eg: pre-reproductive individuals from place of origin (birth place) to another location where the organism will reproduce - Adult dispersal eg: movement to new location as adults

Question 38

what are the benefits of dispersal?

Answer 38

- Key to colonize new areas: Range expansion and shift, for example to respond to climate change - Avoid crowding (high density) where competition can be high and food scarce. Including competition with your parents/offspring (inclusive fitness) - Avoid inbreeding (mating with your relatives)

Question 39

what are the costs of dispersal?

Answer 39

- Exposure to novel conditions: pathogens, habitats, predators… May reduce reproductive success - Increased mortality - Energy investment