Chapter 8 Flashcards
(97 cards)
1
Q
what do life history traits represent
A
the schedule of an organism’s life
2
Q
Life history
A
the schedule of an organism’s growth, development, reproduction, and survival; represents an allocation of limited time and resources to achieve maximum reproductive success
3
Q
the schedule of an organism’s growth, development, reproduction, and survival; represents an allocation of limited time and resources to achieve maximum reproductive success
A
Life history
4
Q
Fecundity
A
the number of offspring produced by an organism per reproductive episode
5
Q
the number of offspring produced by an organism per reproductive episode
A
Fecundity
6
Q
Parity
A
the number of reproductive episodes an organism experiences
7
Q
the number of reproductive episodes an organism experiences
A
Parity
8
Q
Parental investment
A
the time and energy given to an offspring by its parents
9
Q
the time and energy given to an offspring by its parents
A
Parental investment
10
Q
Longevity (life expectancy)
A
the life span of an organism.
11
Q
the life span of an organism.
A
Longevity (life expectancy)
12
Q
what do life history traits often vary consistently with
A
life form, habitat, or environmental conditions
13
Q
What is variation in one life history trait often correlated with
A
variation in other life history traits
14
Q
“slow” life history
A
- long time to sexual maturity
- long life spans
- low numbers of offspring
- high parental investment
Examples: elephants, oak trees
15
Q
“fast” life history
A
- short time to sexual maturity
- short life spans
- high numbers of offspring
- little parental investment
Examples: fruit flies, weeds
16
Q
short life
A
r-selected
17
Q
rapid growth
A
r-selected
18
Q
early maturity
A
r-selected
19
Q
many small offspring
A
r-selected
20
Q
little parental care or protection
A
r-selected
21
Q
little investment in individual offspring
A
r-selected
22
Q
adapted to unstable environment
A
r-selected
23
Q
pioneers, colonizers
A
r-selected
24
Q
niche generalists
A
r-selected
25
prey
r-selected
26
regulated mainly by extrinsic factors
r-selected
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low trophic level
r-selected
28
long life
K-selected
29
slower growth
K-selected
30
late maturity
K-selected
31
few, large offspring
K-selected
32
high parental care or protection
K-selected
33
high investment in individual offspring
K-selected
34
adapted to stable environment
K-selected
35
later stages of succession
K-selected
36
niche specialists
K-selected
37
predators
K-selected
38
regulated mainly by intrinsic factors
K-selected
39
high trophic level
K-selected
40
what did J. Philip Grime proprose
plant life history depends on stress, competition, and the frequency of disturbances
41
stress tolerators
typically small herbs with a long life span, slow growth, and a long time to sexual maturity
42
what do many stress tolerators rely on
vegetative reproduction (reproducing from roots and stems) instead of producing costly seeds
43
ruderals
grow fast and devote a high proportion of their energy to reproduction
44
competitors
when conditions are less stressful, they grow fast, achieve early sexual maturity, and devote little energy to seed production
45
what are life history traits shaped by
trade-offs
46
when one life history trait is favored, it...
prevents the adoption of other advantageous traits
47
Principle of allocation
the observation that when resources are devoted to one body structure, physiological function, or behavior, they cannot be allotted to another
48
the observation that when resources are devoted to one body structure, physiological function, or behavior, they cannot be allotted to another
Principle of allocation
49
what will natural selection favor
individuals that allocate their resources in a way that achieves maximum fitness
50
there is a trade-off between offspring number and...
offspring survival
51
what does an optimized life history resolve
conflicts between competing demands of survival and reproduction to achieve maximum fitness
52
most organisms face a trade-off between the number of offspring they can produce and..
the size of those offspring
53
for many organisms, the number of offspring can be variable, but
the size remains relatively constant
54
what does selection favor in offspring trade-offs
a uniform offspring size
55
for many species, it is possible that acquired energy can only be used...
to produce greater offspring numbers
56
as the number of offspring increases, what decreases
1. the amount of parental care per offspring
| 2. the chances of offspring survival
57
what does offspring number/parental care depend on
environmental conditions such as the number of daylight hours that parents have to find resources for their offspring
58
what does having more offspring do
stimulates the parents to hunt harder for food to feed their offspring
- this can affect the parent's fitness
59
what does allocation of energy to increased fecundity during one year occur at
the cost of further growth that year
60
Determinate growth
a growth pattern in which an individual does not grow any more once it initiates reproduction; occurs in many species of birds and mammals
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a growth pattern in which an individual does not grow any more once it initiates reproduction; occurs in many species of birds and mammals
Determinate growth
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Indeterminate growth
a growth pattern in which an individual continues to grow after it initiates reproduction; occurs in many species of plants, invertebrates, fishes, reptiles, and amphibians
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a growth pattern in which an individual continues to grow after it initiates reproduction; occurs in many species of plants, invertebrates, fishes, reptiles, and amphibians
Indeterminate growth
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why should organisms with a long life span favor determinate growth
it allows them to grow first and reproduce later
65
why should organisms with a short life span favor indeterminate growth
it allows them to quickly reproduce before death
66
what does delaying sexual maturity allow an individual to do
grow large and produce more offspring per year once reproduction begins
67
comparing across many species, the age of sexual maturity is positively associated with
the number of years an animal will survive after reaching maturity
68
organisms differ in the number of times that they reproduce, but
they all eventually become senescent
69
in almost all species, individuals eventually experience a decline in ______ followed by _____.
body condition; death (i.e., senescence)
70
organisms differ in the number of times they _____ before _____
reproduce; senescence
71
Semelparity
when organisms reproduce only once during their life; relatively rare in vertebrates, but common in insects and plants
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when organisms reproduce only once during their life; relatively rare in vertebrates, but common in insects and plants
Semelparity
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Iteroparity
when organisms reproduce multiple times during their life; common among birds, reptiles, mammals, and amphibians
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when organisms reproduce multiple times during their life; common among birds, reptiles, mammals, and amphibians
Iteroparity
75
Annual
an organism that has a life span of one year
76
an organism that has a life span of one year
Annual
77
Perennial
an organism that has a life span of more than one year
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an organism that has a life span of more than one year
Perennial
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when does semelparity arise
when there is a massive amount of energy required for production (ex. bamboos)
80
it has been repeatedly demonstrated that semelparous species produce more offspring in their fatal reproductive episodes than do
closely related iteroparous species in any one of theirs
81
Senescence
a gradual decrease in fecundity and an increase in the probability of mortality
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a gradual decrease in fecundity and an increase in the probability of mortality
Senescence
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an inevitable consequence of natural wear and tear
senescence
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might reflect the accumulation of molecular defects that fail to be repaired
senescence
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the rate of wear can be modified by
physiological mechanisms that prevent or repair damage
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what do long-lived animals appear to have better mechanisms for
reducing the production of reactive forms of oxygen and repairing damaged DNA and protein molecules
87
What does allocation of resources to these mechanisms depend on
the expected life span of an individual; long-lived individuals should select for better repair mechanisms
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what are life histories sensitive to
environmental conditions
89
why is the right timing of life history events critical
so behavior and physiology match changing environmental conditions
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what cues do organisms rely on
various indirect, environmental cues
91
photoperiod
the amount of light that occurs each day; provides a cue for many events in the life histories of virtually all organisms
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the amount of light that occurs each day; provides a cue for many events in the life histories of virtually all organisms
photoperiod
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what do fluctuations in resource availability often determine
the timing of life history events
94
how can predation affect life history traits
time and size at hatching, metamorphosis, sexual maturity
95
what can have substantial impacts on an organism's physiological processes
small changes in temperature
96
what has the increase in global temperature changed of many animals and plants
breeding times
97
changes in temperature can also alter
the initiation of flower production
