Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ecology > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q
  • describes how environmental conditions change over time
  • some is predictable, such as the changing conditions that occur during the day versus during the night or the changes in seasonal conditions that are typical for a given climate
A

temporal environmental variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

occurs from place to place due to large-scale variation in climate, topography, and soil type

A

spatial environmental variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • the position of each individual is independent of the position of other individuals in the population
  • not common in nature
A

random dispersion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why are random dispersions not common in nature

A

abiotic conditions, resources, and interactions with other species are not randomly distributed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • a type of dispersion in which each individual maintains a uniform distance between itself and its neighbors
  • arises from direct interactions between neighbors
A

evenly spaced dispersion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • individuals are aggregate in discrete groups
  • a result of social groups, clustered resources, or offspring that remain close to their parents
A

clustered dispersion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describes the spacing of individuals with respect to one another within the geographic range of a population; can be clustered, evenly spaced, or random

A

dispersion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

true or false:

A population can exhibit one pattern of dispersion at a large scale but a different pattern of dispersion at a smaller scale

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the total number of individuals that exist within a defined area

A

abundance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

why is the total abundance of a population important

A

it provides a measure of whether a population is thriving or on the brink of extinction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • the number of individuals in a unit of area or volume
  • a valuable measure because it tells ecologists how many individuals are packed into a particular area
A

density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what happens if a habitat can support a higher density than currently exists

A

the population can continue to grow in the area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens if the population density is greater than what the habitat can support

A

either some individuals will have to leave the area or the population will experience lower growth and survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where is the highest concentration of individuals located across a large geographic area

A

the center of a population’s geographic range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens as one moves closer to the periphery of the geographic range

A

biotic and abiotic conditions become less ideal and support fewer individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • a measure of the total area covered by a population
  • includes all the areas its members occupy during their life
  • an important measure because it tells us the size of the area a population occupies
A

geographic range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why don’t individuals of a species or population often don’t occupy every location within their geographic range

A

climate, topography, soils, vegetation structure, and other factors influence the abundance of individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which type of temperatures are more hospitable to a greater variety of species

A

warmer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

the more suitable the habitat,

A

the larger a population can grow within that habitat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The process of determining the suitable habitat conditions for a species

A

ecological niche modeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The range of ecological conditions that are predicted to be suitable for a species

A

the ecological envelope of the species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The habitat in which an organism lives is determined by the organism’s

A

niche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

includes the range of abiotic and biotic conditions it can tolerate

A

niche

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  • elaborate male secondary sexual characteristics act as handicaps
  • argues that the greater the handicap and individual carries in terms of a more extreme trait, the greater its ability to offset that handicap with the other superior qualities
A

handicap principle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • a situation in which selection for preference of a sexual trait and and selection for that trait continue to reinforce eah other
  • continues until males run out of genetic variation for the trait or until the fitness costs of possessing extreme traits begin to outweigh the reproductive benefits
A

runaway sexual selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • individuals choose the healthiest mates
  • could be the outcome of either superior genetics or a superior upbringing with abundant resources
A

good health hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q
  • an individual chooses a mate that possesses a superior genotype
A

good genes hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

hypotheses that would cause a female to choose a male based on his traits

A

good genes hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

physical items that a male can provide a female, including a site for raising offspring, a high-quality territory, or abundant food

A

material benefits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

types of female preferences for male traits

A

material and nonmaterial benefits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q
  • a difference in the phenotype between males and females of the same species
  • includes differences in body size, ornaments, color, and courtship behavior
A

sexual dimorphism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Traits related to fertilization–such as gonads

A

primary sexual characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

traits related to differences in body size, ornaments, color, and courtship

A

secondary sexual characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how does sexual dimorphism evolve

A
  • differences in life history between the sexes, contests between males, or mate choice by females
  • humans (hunting)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

a behavior in which one partner prevents the other partner form participating in extra-pair copulations or makes breeding physically impossible

A

mate guarding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

mating systems are shaped by

A
  • natural selection
  • ecological conditions under which each species lives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

when is monogamy favored

A

when males can make important contributions to raising the offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

While a given female hsa a social bond by spending most of her time with only one male, she is actually breeding with other males

A

extra pair copulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

a mating system in which a social bond between one male and one female persists through the period that is required for them to rear their offspring

A

monogamy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

a mating system in which a single individual of one sex forms long-term social bonds and mates with more than one individual of the opposite sex

A

polygamy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

a male mates with more than one female

A

polygyny

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

a mating system in which a single female breeds with multliple males

A

polyandry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

when does polygyny evolve

A
  • when males compete for females and the females all prefer only the best few best males
  • when a male is able to defend a group of females from other males or when a male can control access to a resource that is attractive to multiple females
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

when does polyandry evolve

A

when the female is in search of genetically superior sperm or has received material benefits from each male with whom she mates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q
  • a mating system in which individuals mate with multiple partners and do not create a lasting social bond
  • most common mating system
A

promiscuity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

which takes more energy to produce sperm or egg

A

egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what does a females reproductive success depend on

A
  • number of eggs she can produce
  • quality of mates she finds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

occurs when competition for mates takes place in a limited area and only a few males are required to fertilize multiple females

A

local mate competititon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what does a male’s reproductive success depend on

A

how many females he can fertilize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q
  • describe the number of mates each individual has and the permanence of the relationship among mates
  • subject to natural selection
  • promiscuity, polyandry, polygyny, and monogamy
A

mating systems of species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

when mating options are restricted such that the only mates available for daughters are their brothers, mothers that produce a higher proportion of daughters than sons will have

A

more grand offspring and therefore greater evolutionary fitness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

why do individuals of the less abundant sex enjoy greater reproductive success

A

because they compete with fewer individuals of the same sex for breeding

whenever the population has an abundance of one sex, natural selection will favor any parents that produce offspring of the less abundant sex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

the best sex ratio strategy depends on

A

the frequencies of males and females in a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

occurs when natural selection favors the rarer phenotype in a population

A

frequency-dependent selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

a process of sex selection in which sex is determined largely by the environment

A

environmental sex selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Because the genotype has the ability to produce multiple phenotypes, temperature-dependent sex determination is a type of

A

phenotypic plasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

environmental sex determination that depends on temperature

A

temperature-dependent sex determination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

mechanisms of sex determination

A
  • gametic
  • environmental
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

benefits of asexual reproduction

A
  • 100% of genes passed
  • no investment on sexual organs or behaviors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

costs of asexual reproduction

A
  • accumulation of mutations over generations
  • no new allele combinations
  • higher chances of extinction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

benefits of sexual reproduction

A
  • mutations can be purged
  • new allele combinations (meiosis and fertilization)
  • lower chances of extinction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

costs of sexual reproduction

A
  • 50% of genes passed
  • sexual organs and behaviors are costly (resources, time, exposure to predator and parasites)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

when a mate can be found, the individual prefers to breed by outcrossing to avoid the costs of inbreeding

A

mixed mating strategies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q
  • occurs when an individual uses its male gametes to fertilize its own female gametes
  • poses a fitness cost due to inbreeding depression
A

self-fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

should selection favor individuals that use selfing when they have an opportunity to breed w/ other individuals

A

NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

when hermaphroditic species do not use selfing when they have an opportunity to breed with other individuals

A

outcrossing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

how do some hermaphroditic species avoid the problems of selfing

A

by being sequential hermaphrodites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

If a male individual can invest in female function and gain a great deal of female fitness while only giving up a small amount of male fitness, then selection will favor

A

the evolution of hermaphrodites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

true or false

the total fitness achieved from being a hermaphrodite (i.e. fitness through male function plus female function) exceeds the fitness of being only a male or only a female

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

When male and female structures function at the same time

A

simultaneous hermaphrodite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Plants that have separate male and female flowers on the same individual plant

A

monoecious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

When an individual plant contains only male flowers or only female flowers

A

dioecious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

When an individual possesses one sexual function and then switches to the other

A

sequential hermaphrodite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

The hypothesis that sexual reproduction allows hosts to evolve at a rate sufficient to counter the rapid evolution of parasites

A

the red queen hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

when progeny inherit DNA from two parents through the union of two gametes

A

sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q
  • produced through meiosis within sex organs called gonads
  • contains a single full set of chromosomes
A

gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q
  • inherit DNA from a single parent
  • occurs via vegetative reproduction or parthenogenesis
A

asexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

occurs when an individual is produced from the nonsexual tissues of a parent

A

vegetative reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q
  • Individuals that descend asexually from the same parent and bear the same type
  • produced when germ cells develop directly into egg cells without going through meiosis
A

clones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

a process in which bacteria and some species of protists reproduce by duplicating their genes and then dividing the cell into two identical cells

A

binary fission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q
  • reproduce asexually by producing an embryo without fertilization
  • arise from diploid eggs
  • composed entirely of females
A

parthenogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q
  • germ cells pass through the first meiotic division, but suppression of the second meiotic division results in diploid egg cells
  • differences arise from recombination and independent assortment of chromosomes
A

partial meiosis

84
Q

gamete-forming cells of the female are haploid then fuse to form a diploid embryo

A

complete meiosis

85
Q
  • a 50% reduction in the number of a parent’s genes passed on to the next generation via sexual reproduction vs asexual reproduction
  • ounterbalanced in hermaphrodites
  • can be offset when an individual is either male or female and the male helps the female take care of the offspring
A

cost of meiosis

86
Q

individuals that possess both male and female function

A

hermaphrodites

87
Q
  • The schedule of an organism’s growth, development, reproduction, and longevity
  • Represent the combined effects of many morphological, behavioral, and physiological adaptations of organisms, all of which interact with environmental conditions to affect survival, growth, and reproduction
A

life history

88
Q

which is the number of offspring produced per reproductive episode

A

fecundity

89
Q

the number of episodes of reproduction

A

parity

90
Q

the amount of time and energy given to offspring

A

parental investment

91
Q

the life span of an organism

A

longevity or life expectancy

92
Q

how do life history traits vary

A
  • consistently with respect to life form, habitat, or conditions in the environment
  • variation in one life history trait is often correlated with variation in other life history traits
93
Q
  • long life spans, low numbers of offspring, and a high investment in the energy the parent gives to the offspring, such as parental care, the amount of yolk in an egg, or the amount of energy stored in a seed
  • slow
A

K-selected

94
Q
  • short times to sexual maturity, higher numbers of offspring, little parental investment, and short life spans
  • fast
A

R-selected

95
Q

conceptualized the relationship between life history traits and environmental conditions as a triangle, with each of the three points representing an extreme environmental condition: abiotic stress, competition, and the frequency of disturbances

A

Grime

96
Q

can survive and reproduce under extreme environmental conditions, such as very low water availability, very cold temperatures, or high salt concentrations

A

stress tolerators

97
Q
  • compete for nutrients
  • can grow relatively quickly, because they often spread by vegetative reproduction
  • tend to grow to larger sizes and exhibit long life spans
A

competitors

98
Q
  • low stress and high frequency fo disturbance
  • colonize disturbed patches of habitat, exhibit fast growth and earl maturation, and use a high proportion of their energy to make seeds
  • typically have seeds that are easily dispersed and that can persist in the environment for many years as they wait for favorable environmental conditions to germinate
A

ruderals

99
Q
  • reflects the genetic makeup of the organism
  • the result of how an organism allocates a finite amount of time, energy, or nutrients
A

trade-offs

100
Q

when resources are devoted to one body structure, physiological function, or behavior, they cannot be allocated to another

A

principle of allocation

101
Q

selection favors what type of offspring size

A

a uniform, perhaps even optimal, offspring size and that an individual able to acquired additional energy can use it to make greater numbers of offspring

102
Q

As the number of offspring increases, the efforts of the parents to provide food and protection will be

A

increasingly spread thin

103
Q

neither phenotype does well in both environments

A

phenotypic trade-off

104
Q

the ability of a single genotype to produce multiple phenotypes

A

phenotypic plasticity

105
Q

when does the fitness advantage of phenotypic plasticity occur

A

whenever environmental variation in space or time occurs frequently

106
Q

an environmentally induced change in an individual’s physiology

A

physiological plasticity / acclimation

107
Q

induced changes in what are more difficult to reverse

A

morphology and life history

108
Q

When environments fluctuate rapidly relative to the length of an individual’s lifetime, selection should favor

A

plastic behavioral and physiological traits because these traits can often respond rapidly and reverse rapidly

109
Q

the seasonal movement of animals from one region to another

A

migration

110
Q

Where environmental variation shifts the food supply from feast to famine and migration is not a possibility, what can be an adaptive strategy

A

storing resources

111
Q

a condition in which animals dramatically reduce their metabolic processes

A

dormancy

112
Q

types of dormancy

A

diapause
hibernation
torpor
aestivation

113
Q

a type of dormancy that is common in insects and other animals in response to unfavorable environmental conditions

A

diapause

114
Q

a less extreme type of dormancy that occurs in endotherms, in which animals reduce the energetic costs of being active by lowering their heart rate and decreasing their body temperature

A

hibernation

115
Q

a brief period of dormancy during which the animal reduces its activity and its body temperature decreases to help conserve energy

A

torpor

116
Q

the shutting down of metabolic processes during the summer in response to hot or dry conditions

A

aestivation

117
Q

The idea that animals should strive for the best balance between the costs and benefits of different foraging strategies

A

optimal foraging theory

118
Q

responses to food variation in space and time

A

central place foraging, risk-sensitive foraging, optimal diet composition, and diet mixing

119
Q

acquired food is brought to a central place, such as a nest with young

A

central foraging theory

120
Q

The total time it takes to obtain the food depends on the time needed to fly round-trip to the food site

A

traveling time

121
Q

time spent obtaining food once the animal arrives at the site

A

searching time

122
Q

Animals that incorporate the risk of predation into their foraging decisions

A

risk-sensitive foraging

123
Q

why does natural selection occur

A

because of differences in survival or reproduction among individuals endowed with different phenotypes in a particular environment

124
Q

favors any combination of traits that collectively provide improved survival or reproduction to an individual

A

natural selection

125
Q

a type of seleciton in which humans decide which individuals will breed and the breeding is done with a preconceived goal for the traits desired in the population

A

artificial selection

126
Q
  • the evolution of populations
  • pervasive
  • affected by both random processes and selection
  • can be divided into artificial and natural selection
A

microevolution

127
Q

what types of populations tend to experience more genetic drift

A

small populations

128
Q
  • individuals with extreme phenotypes at either end of the distribution can have higher fitness than individuals with intermediate phenotypes
  • increases genetic and phenotypic variation within a population
A

disruptive selection

129
Q

occurs when an extreme phenotype experiences higher fitness than the average phenotype of the population

A

directional selection

130
Q
  • individuals with intermediate phenotypes have higher survival and reproductive success than those with extreme phenotypes
  • sweeps away harmful genetic variation
A

stabilizing selection

131
Q

the nonrandom process by which certain phenotypes survive and reproduce better within a given environment than other phenotypes

A

selection

132
Q

how can selection influence the distribution of traits in a population in three ways

A
  • stabilizing selection
  • directional selection
  • disruptive selection
133
Q

occurs when genetic variation is lost due to random variation in mating, mortality, fecundity, or inheritance

A

genetic drift

134
Q

why is genetic drift more common in small populations

A

because random events can have a disproportionately large effect on the frequencies of genes in the population

135
Q

ways genetic drift occurs

A
  • bottleneck effects
  • founder effects
136
Q
  • when a population experiences a severe reduction in population size
  • the survivors carry only a fraction of the genetic diversity that was present in the original, larger population
  • smaller population will possess different gene frequencies than the earlier, larger population
A

bottleneck effect

137
Q

A substantial barrier that prevents dispersal between suitable habitats

A

dispersal limitation

138
Q

what is a common dispersal limitation

A

the presence of large expanses of inhospitable habitat that an organism cannot cross

139
Q

strips of favorable habitat located between large patches of favorable habitat

A

habitat corridors

140
Q
  • When all individuals have perfect knowledge of habitat variation and they distribute themselves in a way that allows them to have the same per capita benefit
  • tells us how individuals should distribute themselves among habitats of differing quality
A

ideal free distribution

141
Q

resources available to each individual

A

per capita benefit

142
Q

Lack’s hypothesis

A
  • life history traits not only contribute to reproductive success, but also influence ecolutionary fitness
  • life histories vary consistently w/ respect to factors in the environment
  • number of offspring parents can successfully rear is limited by food supply
143
Q

which types of birds contradicted Lack’s hypotheses

A

tropical birds

more food per nestling

144
Q
A
145
Q

what diminishes benefits to the parents in terms of the number of offspring that survive

A

increasing the number of offspring

146
Q

how do we determine the optimal food decision

A

balance the energy obtained from the prey and the handling time

energy benefit / handling time

147
Q

the time required to subdue and consume the prey

A

handling time

148
Q
  • occurs when a small number of individuals leave a large population to colonize a new area and bring with them only a small amount of genetic variation
  • genetic variation remains low until enough time has passed to accumulate new mutations
A

founder effect

149
Q

if several genes influence body size

A

an individual’s size will depend on the mix of alleles for all of these genes

150
Q

the tendency for individuals to be concentrated toward the center of the distribution reflects

A

the relative improbability of an individual inheriting mostly alleles that code for large body size or mostly alleles that code for small body size

151
Q

a phenomenon when females do not grow anymore after initiating reproduction

A

determinate growth

152
Q

continued growth after initiating reproduction

A

indeterminate growth

153
Q

what is the key feature of shaping the trade-off between growth and reproduction is that

A

larger females commonly produce more offspring

154
Q

increased fecundity during one year occurs at the cost of

A

further growth that year

155
Q

an organism with a long life expectancy should favor what during the early years of its life

A

growth over fecundity

156
Q

the number of new individuals that are produced in a given amount of time minus the number of individuals that die

A

growth rate of a population

157
Q

when individuals reach maximum reproductive rates and minimum death rates under ideal conditions

A

intrinsic growth rate (r)

158
Q
  • growth is exponential under ideal conditions
  • when conditions are ideal, the size of the population in the future (Nt) depends on the current size of the population (N0)
  • the population’s intrinsic growth rate (r), and the amount of time over which the population grows (t)
  • e = base of natural log (2.72)
A

exponential growth rate

159
Q

populations with higher intrinsic growth rates or a larger number of reproductive individuals will

A

experience a greater rate of increase in population size

applies to humans

160
Q

the exponential growth model produces what shaped curve

A

J

161
Q

how do we determine the rate of growth at any point in time using the exponential mdoel

A

dN/dt = rN

  • this equation tells us that the rate of change in population size at any particular point in time depends on the population’s intrinsic growth rate and the population’s size at that point in time
  • The derivative form of the equation tells us the slope of the line relating population size to time at any given point
162
Q

the time required for a population to double in abundance

A

doubling time

163
Q

which animals grow more rapidly: endotherms or ectotherms

A

endotherms

164
Q

for species that breed once…

A

physiological decline and death follow rapidly

165
Q

for species that breed many times…

A

the decline in physiology comes more gradually

166
Q
  • the phenomenon of an organism reproducing only once
  • relatively rare in vertebrate animals, more common in insects and many species of plants
  • live under more extreme ecological conditions
A

semelparity

167
Q
  • the phenomenon of an organism reproducing multiple times throughout their life
  • a common life history that occurs in most species of birds, mammals, fish, reptiles, and amphibians
A

iteroparity

168
Q

variable environment + variable phenotype =

A

better survival

169
Q

true or false:

plastic individuals are usually fitter than a non-plastic individual in their own environment

A

false

Plastic individuals aren’t usually fitter than a non-plastic individual in their own environment, it’s the ability to react that increases fitness

170
Q
  • micro + speciation
  • descent with modification, speciation
A

macroevolution

170
Q

requirements for evolution to occur

A
  • phenotypic varaiton
  • traits are heritable
  • differential reproductive success
  • success determined by heritable traits
171
Q

have similar gamets in both parents

A

isogamy species

172
Q

have different gametes in each parent

smaller ones - male, larger ones - female

A

anisogamy species

173
Q

how individuals try to maximize their own reproductive fitness

A
  • mate guarding
  • copulatory plugs
  • infanticides
  • traumatic insemination
174
Q

sex ratio in a population is controlled by

A

frequency-dependent selection

175
Q
  • a sexual trait and selection for that trait reinforce each other
  • might impose a handicap on the bearer
A

runaway selection

176
Q

the result of diverse sex determination systems

A

sexual dimorphisms

177
Q

save up resources to “finance” reproduction

A

capital breeders

178
Q

reproduction depends on available resources in current environment

A

income breeders

179
Q

higher latitude =

A

better clutch size

180
Q

the decrease in fertility and increase in probability of death over the course of a lifespan

A

senescence

181
Q

live only in one specific are

A

endemic species

182
Q

live in a wide range of geographic areas

A

cosmopolitan species

183
Q

density varies by

A

body size, resource availability, location within range

184
Q

higher population density has negative effects on population growth (disease)

A

negative density dependence

185
Q

higher population has positive effects on population growth (mating and allee effects)

A

positive density dependence

186
Q

a phenomenon characterized by a correlation between population size or density and the mean individual fitness of a population or species

A

allee effect

187
Q

methods to measure abundance

A
  • subsampling (line transect and area/volume search)
  • indices (indirect counts of evidence)
  • mark-recapture
188
Q

M/N = R/C

M = # caught in first sampling
N = total # in population
R = # recaptured (in second sample)
C = # captured in second sample

A

mark-recapture method

189
Q

how do we measure indices

A

indirect counts of evidence

190
Q

the rate of deterioration can be modified by

A
  • a variety of physiological mechanisms that either prevent or repair damage (take time, energy, nutrients, and tissues
  • depends on the expected life span of the individual
191
Q

when a population has a low survival rate, selection should favor

A

improvements in reproductive success at young ages and selection to delay senescence should be weak

192
Q

in a population with a high survival rate, selection for … should be strong

A

delayed senescence

193
Q
  • compares population sizes at regular time intervals
  • expressed as a ratio of a population’s size in 1 year to its size in the preceding year (or some other time interval)

N1=N0λ

A

geometric growth model

194
Q
A
195
Q

λ > 1 means

A

the population size has increased from 1 year to the next because there have been more births than deaths

196
Q

when λ > 1,

A

the population size has decreased from 1 year to the next because there have been fewer births than deaths

197
Q

why is the value of λ always positive

A

there cannot be a negative number of individuals

198
Q

Nt=N0λt where t equals time.

A

geometric growth model

199
Q

how are geometric and exponential growth related

A

by λ=er which can be rearranged to loge​λ=r

λ and r are directly related to each other

200
Q

when a population is decreasing,

A

λ<1 and r<0

201
Q
A
202
Q

when a population is constant,

A

λ<1 and r<0

203
Q

When a population is increasing

A

λ>1 and r>0

204
Q

equation for doubling time (the exponential model)

A

e^(rt) = Nt/N0

205
Q

doubling time equation (geometric model)

A

loge2/logeλ

Ecology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions