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Flashcards in Ch. 9 Lecture Deck (32)
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1
Q

Life History

A

life time pattern of GROWTH, DEVELOPMENT, and REPRODUCTION

2
Q

Questions we ask about life history

A
  • What age do individuals mature and reproduce?
  • How many offspring are produced over a lifetime?
  • How long do individuals live?
3
Q

Life History Traits= ?

A

fitness components

4
Q

What do we measure?

A

life history traits = fitness components

(SMORRGL)

  • Size at birth
  • Maturity (Age and Size)
  • Offspring (Number, Size, and Sex)
  • Reproductive Effort (Age-, Stage-, or Size-Specific)
  • Rates of Survival (Age-, Stage-, or Size-Specific)
  • Growth pattern
  • Lifespan
5
Q

Reproductive success influences populations!!!

A

Reproductive success influences populations!!!

6
Q

The evolution of life histories involves…

A

trade-offs

7
Q

What causes trade-offs in life history traits?

A

compensating for environmental variation is metabolically costly

8
Q

Reproductive Effort

A

total energetic cost of reproduction per unit time

9
Q

Herbaceous perennials reproductive effort

A

15-20% net production

10
Q

Corn reproductive effort

A

35-40% net production

11
Q

Common lizard reproductive effort

A

7-9% annual energy

12
Q

Allegheny Mountain Salamander reproductive effort

A

48% annual energy

13
Q

How does an organism distribute its limited resources?

A
  • reproduce early v. later in life
  • produce many smaller v. fewer larger offspring
14
Q

What imposes trade-offs?

A
  • Physiology
  • Energetics
  • Physical environment
  • Biotic environment
15
Q

Parental Care

A

Altricial v. Precocial

16
Q

Altricial

A

require LONGER parental care because young are born somewhat HELPLESS

17
Q

Precocial

A

require no or VERY LITTLE parental care because young are born relatively MATURE

18
Q

Reproduction involves benefits and costs: Hypothesis

A

Behavioral, physiological, and energetic activities involved in REPRODUCTION REDUCES future reproductive success in the form of reduced SURVIVAL, FECUNDITY, and/or GROWTH.

19
Q

fecundity

A

actual reproductive rate measured by number of gametes produced

20
Q

age v. fecundity

A

age of reproductive maternity is a key aspect of life history. as age increases, cumulative number of offspring increases.

21
Q

Cost of delaying reproduction

A

predation

22
Q

extrinsic factors that can influence age of reproductive maturity and annual reproduction

A
  • winterkill
  • predation
  • reabsorb fetus if conditions unfavorable/dominant male present
23
Q

Phenotypic Plasticity

A

ability of an individual to change form under different environmental conditions

24
Q

trade-offs between number and size of offspring

A

each offspring takes resources, which are limited.

-size at birth v. survivorship

25
Q

timing v. number of reproduction

A

semelparous v. iteroparus

26
Q

semelparous

A

reproduces once in life and then dies (insect)

27
Q

iteroparus

A

reproduces multiple times over a life time (shark)

28
Q

organizing life history traits

A

k-selected v. r-selected species

29
Q

r-selected species

A
  • small size
  • fast development
  • reproduces early in life
  • many small offspring
  • fast pop. growth rate
  • no parental care
  • weak competitive ability
  • variable pop. size, below carrying capacity
  • variable and unpredictable mortality
30
Q

k-selected species

A
  • large size
  • slow development
  • long lived
  • reproduces later in life
  • few large offspring
  • slow pop. growth rate
  • parental care
  • strong competitive ability
  • constant pop. size, close to carrying capacity
  • constant and predictable mortality
31
Q

r-selected->k-selected spectrum

A

bacteria > mollusks > insects > fish > amphibians > reptiles > mammals > humans

32
Q
A