Exam 2 Flashcards
(203 cards)
1
Q
Spatial structure
A
The pattern of density and spacing of individuals in a popuation
2
Q
Niche
A
the range of abiotic and biotic conditions in which a species can persist
3
Q
What are the two types of niche
A
fundamental niche
realized niche
4
Q
fundamental niche
A
the range of abiotic conditions under which a species can persist
(allow a pop to survive, grow, and reproduce)
-temp, humidity
5
Q
realized niche
A
The range of abiotic and biotic conditions under which a species can presist
-determines the geographic range of a species
6
Q
geographic range
A
a measure of the total area covered by a pop.
7
Q
fundamental and realized niche on a graph
A
Fundamental- includes all evevations
realized- includes high elevation only
8
Q
what are the limits for the barnicles from spreading down?
A
fundemental niche
9
Q
could the realized niche ever be larger than the fundamental niche
A
Yes! for ex the presence of a mutualist can allow a species to survive abiotic conditions that it couldn’t handle on its own
10
Q
The realized niche determines the geographic range of species… HOW
A
places where abiotic and biotic condictions are within the range in which the species can persist
11
Q
Ecological niche models
A
The process of determining the suitable habitat conditions for a species
12
Q
2 reasons why a species might be absent from a location that an ecological niche model predicted to be suitable: why it might be wrong
A
-site really is suitable, but the species can’t get there (barrier, too far, not enough of them there)
-missing an important abiotic or biotic factor (presence of competitors)
13
Q
ecological envelope
A
the range of ecological conditions that are predicted to be suitable for a species
14
Q
endemic
A
species that live only in a small localized region, often isolated
15
Q
cosmopolitan
A
species with very large geogrephic ranges that can span several continents
(huge geographic ranges)
16
Q
characteristics of population distributions
A
geographic range
abundance
density
dispersion
dispersal
17
Q
abundance
A
total number of individuals
18
Q
density
A
number of individuals/ unit of an area or volume
19
Q
dispersion
A
the spacing of individuals
-clustered
-evenly spaced
-random
20
Q
the three types of dispertion
A
clustered
evenly spaced
random
21
Q
clustered dispersion
A
a pattern of pop dispersion in which individuals are aggregated in discrete groups
resources are clusterd
clonal reproduction
social groups
22
Q
evenly spaced dispersion
A
a pattern of dispersion of a pop in which each individual maintains a uniform distance between itself and its neighbours
competition
defending territores
chemicals
23
Q
random dispersion
A
a pattern of dispersion of a pop in which the position f each individual is independent of the position of other individuals in the pop
-wind=random for seeds
-not very common in nature
24
Q
dispersal
A
the movement of individuals from one area to another for good
25
cenus
counting every individual in pop
-cant usual do so we take a sample
26
survey
counting a subset of a pop
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types of samples
area/volume based
-quadrant
line-transect
mark-recapture
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area- and- volume based surveys
surveys that define the boundaries of an area or volume and the count all of the individauls in the space
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line-transect surveys
surveys that count the number of individuals observed as one moves along a line
30
mark-recapture surveys
a method of population estimation in which researchers capture and mark a subset of a pop from an area, return it to the area, and then capture a second sample of the pop after some time has passed
31
which of the following pop would be best estimated by an area-based survey?
flowers in a field
-they are relatively immobile
32
dispersal limitation
the absence of a pop from suitable habitat because of barriers to dispersal
33
one way to remove dispersal barriers?
corridors
-removed by humans moving them ourselves
34
lifetime dispersal distance
the average distance an individual moves from where it was hatched or born to where it reproduces
35
metapopulation
a bunch of subpopulations more or less linked by dispersal
36
three main metapopulation models
1- basic
2- source-sink
3- landscape
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habitat corridors
a strip of favourable habitat located between two large patches of habitat that facilitates dispersal
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ideal free distribution
when individuals distribute themselves among different habitats in a way that allows them to have the same per capita benefit
39
subpopulations
when a larger pop is broken up into smaller groups that live is isolated patches
40
basic metapopulation model
describes a scenario in which there are patches of suitable habitat embedded within a matrix of unsuitable habitat
-patches are equally suitable
-matrix is not suitable
-% of patches occupied is determined by rates of colonization and extinction
41
what is matrix?
unsuitable habitat
42
the source-sink metapop model:
pop model that builds upon the basic metapop model and accounts for the fact that not all patches are sutiable habitat are of equal quality
-lower quality patches are "sinks"
-higher quality patches are "sources"
-source patches provide individuals that disperse into the sink patches - if it didn't then sub populations in sink patches would go extinct
-pop in sink patches have lower reproduction
43
sink subpopulations
in low-quality habitats, sub pop that relay on outside dispersers to maintain the subpop within the metapop
44
landscape metapop model
considers both differences in the quality of the suitable patches and the quality of the surrounding matrix
-some patches are more suitable than others
-matrix can also be more or less suitable or more or less easy for the species to disperse through
-more realistic but also more complicated
45
Why do populations go over their carrying capacity in real life?
Delayed response to reduced per capita resources
46
what causes delays in density dependence?
when density dependence is a pop density in the past, not currently
47
Demongraphy
study of populations
48
Growth rate
in a pop, the number of new individuals that are produced in a given amount of time minus the number of individuals that die
49
geometric growth model:
used for species that reproduce all at once, one time/ year
50
intrinsic growth model
r
the highest possible per capita growth rate for a pop
51
exponential growth model
a model of pop growth in which the pop. increases continously at an exponential rate
52
j-shaped curve
the shape of exponentail growth when graphed
53
doubling time
the time required for a pop to double in size
54
difference between geometric and exponential growth models
the describe the same thing, but geometric pop growth in discrete steps
55
No pop. can keep growing exponentially
-limits to pop growth can be density independent or density dependent
56
density independent
factors that limit pop size regardless of the pops density
usually caused by things like weather, storms,fires ect.
57
density dependent
factors that affect pop size in relation to the pop's density
-can be negative or positive
58
negative density dependence
when the rate of population growth decreases as pop density increases
-higher pop, less food, so growth rate goes down
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positive density dependence
when the rate of pop growth increases as pop density increases
-lower pop, harder to find mates, growth rate goes down
-also known as inverse density dependence or the allee effect
60
can populations be regulated by both positive and negative density-dependent factors?
Yes!
61
self-thinning curve
a relationship that shows how decreases in pop density over time lead to increases in the size of each individual in the pop
62
logistic growth model
-more realistic than expoential
-pop have limits
63
carrying capacity (K)
The max pop. size that can be supported by the environment
64
s-shaped curve
the shape of the curve when a pop. is graphed over time using the logistic growth model
65
inflection point
the point on sigmoidal growth curve at which the pop achieves its highest growth rate
66
life tables
display class-specific survival and fecundity data
67
age structure
in a pop, the proportion of individuals that occurs in different age classes
68
what are the two types of life tables?
Cohort
Static
69
cohort life tables
-follow a group of individuals all born at the same time until all of them die
70
static life tables
quantify fecundity and/or survival of all individuals (all ages) in a single time interval
71
stable age distribution
when the age structure of a pop does not change over time
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generation time (T)
the average time between the birth of an individual and the birth of its offspring
73
Cons to cohort tables
low rates of survival/fedundity could be due to ALL individuals in that class experiencing the same environmental conditions
-have to wait a long time for the data
74
static pro and cons
pro:
track survival of each group at one time
all age classes experience the same environmental condition
dont have to wait decades/centuries for data to die out
cons:
need to measure age accurately
only represents birth/fecundity rates given environmental conditions of sampling time frame
75
What causes delays in density dependence?
time delay in developmental stages
-food abundance in moose determines the number of calves that will be born in the spring
-ability to store resources and use those stages when resources become scarce
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overshoot
when a pop grows beyond its carrying capacity
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die-off
a substantial decline in density that typically goes well below the carrying capacity
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population cycles
regular oscillation of a pop over a longer period of time
79
damped oscillations
the pop initially oscillates but the magnitude of the oscillations declines over time
80
stable limit cycle
the pop continues to exhibit large oscillations over time
81
Deterministic models
do not account for random variation in pop growth rate
in real life there is lots of random variation
82
stochastic models
incorporate random variation in pop growth models
83
demographic stochasticity
variation in birth rates and death rates due to random changes differences among individuals
84
environmental stochasticity
variation in birth rates and death rates due to random changes in the environmental conditions
85
What causes stochastic model variation?
demographic stochasticity
and
environmental stochasticity
86
Why are smaller populations more vulnerable to extinction?
string of bad years can drive the pop. extinct faster in small pop than in large pop
87
what are the 3 types of metapop
basic
source-sink
landscape - most realistic
88
habitat fragmentation
the process of breaking up large habitats into a number of smaller habitats
89
I you were trying to save an endangered species that lived in a metapopulation, how might you try to increase the proportion of occupied patches?
- increase C
-corridors
-decrease e
-improve the habitat by reducing predator by increasing resources
90
how synchronized the sub-pops are depends on-
how much dispersal is going on between them
91
proportion of occupied patches can be approx the same even though-
patches are occupied can change
92
patches in real life
-different sizes and different quality
-are differemt distances from each other
-matrix not completely inhospitable
93
the number of individuals in a patch (sub pop) depends on
-distance from other patches
-size of patch
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rescue effect
when individuals dispersering to a patch from another patch prevents that subpop from going extinct
95
Why would a little patch have so many butterflies
really close to other patches or close to 1 big patch
small patch is a "sink"
96
What are the two types of predators
mesopredator
top predator
97
mesopredator
relatively small carnivores that consume herbivores (weasal, cat)
98
top predators
predators that typically consume both herbivores and mesopredators (lions, sharks, wolves)
99
mesopredator expansion
when humans kill top predators, mesopredators expand
100
lotka-volterrea model
a mathematical model of predator-prey interactions
101
what is the purpose of lotka-volterra model?
to explain mathematically why and how predator and prey pop. cycle in relation to each other
102
Equilibrium isocline
the pop size of one species that causes the pop of another species to be stable
also known as zero growth isocline
103
What is a functional response
the relationship between prey density and an individual predators rate of eating them
change in the rate of prey consumption with change in density of prey (more prey = more for each predator)
104
how many functional responses are there?
3
105
type 1 functional response
predators eats more and more until predator reaches satiation
106
type 2 functional response
number of prey consumed per predator slows gradually and then plateaus
-due to handling time (can only eat some parts of the food)
107
type 3 functional response
low rates of consumption at low prey density (prey hard to find, hiding, poor search image, prey switching), then increases quickly, then slows gradually
108
joint pop trajectory
the simultanous trajectory of predator and prey pop.
109
joint equilibrium point
the point at which the equilibrium isoclines for predator and prey pop cross
110
search image
a learned mental image that helps the predator locate and capture food
111
numerical response
a change in number of predators in response to change in prey density
-pop growth
-movement
112
what are the defences against predation and herbivory
behavioural
crypsis
structural
chemical
tolerance to herbivory
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behavioural defence
alarm calling, running away, reduced activity
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crypsis defence
camoflage to blend better with background
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structural defence
quills on a pourcupine, spines or prickles on plants
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chemical defence
toxins, smelly chemicals
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tolerance to herbivory
dropping a tail
118
warning colouration
colours and patterns on bugs means distastefulness
also known as aposematism
119
batesian mimicry
when palatable species evolve warning colouration that resembles unpalatable species evolve a similar pattern of warning colouration
120
mullerian mimicry
when several unpalatable species evolve a similar pattern of warning colouration
121
carotenoids
chemicals which make ladybugs red in colour
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alkaloids
chemicals that make ladybugs bitter
less food = less production of defence chemicals
123
coevolution
when 2 or more species affect each others evolution
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half of all species on earth are what?
parasites
125
what is a parasite?
an organism that gets its energy from living in or on another organism and cause harm to that organism by doing so
126
How are parasites different from predators
they are smaller than their hosts
usually dont kill their hosts
usually live in/on one individual
127
how do hosts deal?
infection resistance
infection tolerance
128
infection resistance
ability of a host to prevent an infection from occurring
-immune system
129
infection tolerance
ability of a host to minimize the harm that an infection can cause
130
parasite load
the number of parasites of a given species that an individual host can harbour
131
ectoparasite
a parasite that lives on the outside of an organism
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what are the two types of parasites
endoparasites
ectoparasites
133
endoparasites
live inside the host
134
ectoparasite pros and cons
pros:
low exposure to immune system
easier to move from host to host
cons:
high exposure to environment
can be more difficult to feed (peirce through skin)
135
endoparasite pros and cons
pros:
protection from environment and enemies
easy to feed
cons:
exposed to the immune system
harder to move from host to host
136
types of endoparasites
viruses
prions
protozoans
bacteria
fungi
helminths
137
viruses
small pox, covid
138
prions
mad cow disease, chronic wasting disease
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protozoans
malaria
140
bacteria
STDs, plague
141
fungi
white nose syndrome in bats
142
helminths
hookworms, lungworms
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emerging infectious disease
a disease that is newly discovered or has been rare and then suddenly increases in occurrence
144
Why are eurpean bats not dying from white nose
-fungus is not native to north america but is native to europe so bats there have evolved either tolerance or resistance
or the fungus in north america has mutated to become more lethal
145
horizontal transmission
when a parasite moves between individuals other than parents to their offspring
146
vector
an organism that a parasite uses to disperse from one host to another
mosquitos = vectors for malaria
147
vertical transmission
when a parasite is transmitted from parent to its offspring
148
reservoir species
species that can carry a parasite but do not succumb to the disease that the parasite causes in other species
sars- bats can carry but dont have it
149
how can parasite avoid extinction if its host goes extinct?
-evolve ability to infect a new host
-live in the environment or in a reservoir species until the host pop. comes back
150
S-I-R
susceptible
infected
resistant
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SIR model
simpilest model of infectious disease transmission that incorporates immunity
152
what would make R0 smaller?
-increase g
-antivirals
-decrease B
-isolation, wash hands, covid stuff
-decrease S
-vaccine
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What is s in R0 = s x b/g
number of susceptible individuals
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what is b in R0 = s x b/g
rate of transmission
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what is g in R0 = s x b/g
rate of recovery
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is R0 > 1
epidemic
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if R0 < 1
infection dies out
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What is competition
a negative interaction between two species that depend on the same limiting resource to survive, grow, and reproduce
159
intraspecific competition
competition among indivuduals of same species
160
interspecific competition
competition among individuals of different species
161
what is a resource?
things that can be used up/ consumed
"there isnt enough____ for all of us!"
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renewable resources
resources that are constantly regenerated
163
nonrenewable resources
resources that are not regenerated
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liebigs law of the minimum
law stating that a pop. increases until the supply of most limiting resource prevents it from increasing further
165
gause
famous experiments with protists
166
two species cannot coexist indefinitely when they are both limited by the same resource
-two protist species that both consume bacteria
-two species of diatoms that both consume phosphorus
-two species of birds that both eat the same insect species
167
Darwin predicted that more closely realted species would compete more intensely... why?
more closely related species would share similar traits, therefore consume similar resources (similar niche)
168
How do we see closely related species living near each other without competitive exclusion
natural selection over time, favors slight difference in habitat/resources which prevents competitive exclusion
169
competitive exclution principle
two species cannot coexist when they are both limited by the same resource
170
competition coefficeints
varaibles that convert between the number of individuals of one species and the number of individuals of the other species
171
purpose of the lotka-volterra competition models
to help us predict how the different carrying capacities (K) and different starting numbers (N) of the two species will influence how competition will turn out
172
zero pop growth isoclines
combinations N1 and N2 where pop growth rate is 0
173
Limitaion of simple 2-species competition model:
-based on 1 resource only (usually more than one resource)
- two species are competing in isolation (usually more species around)
-does not account for changing abiotic conditions or predation or herbivory
174
animals that move around and feed a lot are good competitors, but get eaten by predators more
-some plants are good competitors but more susceptible to herbivores
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exploitative competition
competition in which individuals consume and reduce a resource to a point that other individuals cannot survive
176
interference competition
when competitors do not immediately consume resources but defend them
177
allelopathy
a type of interference that occurs when organisms use chemicals to harm their competitors
178
apparent competition
when 2 species negatively affect each other via an enemy (predator, parasite, herbivore)
179
mutualism
a positive interaction between individuals of 2 species in which each species recieves benefits from the other
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predation/parasitoidism interaction
1 = +
2 = -
181
parasitism interactions
1 = +
2 = -
182
herbivory interactions
1 = +
2 = -
183
competition interactions
1 = -
2 = -
184
mutualism interactions
1 = +
2 = -
185
commensalism interactions
1 = +
2 = 0
186
ant on acacia tree mutualistic relationship
acacia provides food for ants
ants defend tree against herbivores
187
how can we be sure that the acacia trees are getting a benefit?
an experiement!
188
Generalist
a species that interacts (forms a mutualism) with many other species
189
specialist
a species that forms a mutualism ONLY with one particular species (or a few closely related species)
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obligate mutualists
requires mutualsit partner to survive
191
facultative mutualists
can live without their partner if necessary
192
What do species get from mutualisms
resources
-nutrients, water, sugar, shelter
defence from predators
193
arbuscular mycorrhizal fungi
a type of endomycorrhizal fungi that infects a tremendous number of plants including apple trees, peach trees
194
ectomycorrhizal fungi
fungi characterized by hyphae that surrund the roots of plants and enter between root cells but rarely enter the cells
195
termites and protozoans
they get resource
-protozoans gets lots of wood to break down (shelter)
-termites get products of wood digestion
196
oxpecters and mammals
get defense
oxpeckers gets food (ticks)
mammals get ticks removed
197
bats and plants
gets pollinator
bats get nector
plants get pollen spread
198
ants and some plants
get seed dispersal!
ants get oil and protein rich elaisome
plant gets seed dispersed
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specialist mutualists could be more vulnerable to becoming endangered
big fruits only elephant can eat can only germinate after passing through elephant
-elephants are declining so tree is also declining
200
endophytic fungi
fungi that live inside a plants tissues
201
cheaters
-recieves benefit but provides nothing in return
-natural selection favours this cuz cheater gets fitness benefit with no cost
202
example of when natural selection prevents cheating
plant can determine when fungus is not providing and release more sugars to the non cheating fungi when the fungi is seperated
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