1
Q
parental care: for only the female to care
A
M: SP1 + mSP1 > SP2
F: SP1 > LP0
2
Q
species richness
A
number of species present in an area
3
Q
distribution
A
spatial arrangement of individuals within a population
–> uniform: regularly or uniformly spaced (less common)
–> random: individuals are equally likely to occur anywhere
–> clumped: more likely to be found in some areas than in others
–> uniform less common, clumped more common in nature
–> competition promotes uniform distribution
4
Q
intrasexual selection
A
traits increasing competitiveness against others of the same sex
5
Q
early-successional species (r)
A
high reproductive output
high dispersal ability (random dispersal)
fast growth rates, especially in full sun
6
Q
life history traits
A
growth rate
size at maturity
age at repro maturity
age at first repro
frequency/number of repro events
number of offspring
size of offspring
parental care
juvenile survival
adult survival
lifespan
investment in defense
7
Q
altriusm
A
selfless behavior: alarm calls, self-sacrifice, alloparenting
–> benefiting others at the expense of the individual
8
Q
case study: loggerhead turtles
A
age-specific survival rates used to manage population, understand how to reverse a decline
–> most efforts focused on eggs and hatchlings, but large juveniles had lowest rates of survivorship over longest period of time
–> fishing policy change: Turtle Excluder Device allows turtles to swim out of nets but keeps fish in
9
Q
decrease in N2O emissions
A
ecological restoration of farmland = good implications for soil nitrogen cycling
10
Q
interaction: +, 0
A
commensalism (doesn’t usually exist)
11
Q
sexual selection
A
selection for/against a trait due to effect on mating success
–> explains dimorphism, particularly extravagant traits which natural selection would not favor
12
Q
Lotka-Volterra: mutualism - lines start at K1 and K2 < 0, increase and intersect OR obligate with a >/= 1
A
unstable obligate mutualism
–> species will either “run away together” or both go extinct, depending on what shift occurs
13
Q
population size
A
number of individuals
–> increase: births, immigration
–> decrease: deaths, emigration
14
Q
hermaphroditism
A
each individual produces both gamete sizes
15
Q
case study: sampling effect
A
ladybugs as a predator for aphids (compared to other predators)
–> ladybug alone was greatest contributor to aphid deaths
16
Q
case study: carbon sequestration as a regulating service
A
established plots with different levels of biodiversity (1, 2, 4, 8, 16 species from 4 functional groups; treatments varied on diversity and functional diversity)
–> C3 grass: single-step photosynthesis
–> C4 grass: two-step photosynthesis, minimal respiration
–> legume: nitrogen-fixing
–> nonlegume forb: other
–> results: higher-diversity plots stored more soil and root carbon on a yearly basis
17
Q
parental care: for neither parent to care
A
M: SP0 + mSP0 > SP1
F: LP0 > SP1
18
Q
genetic diversity
A
genotypic (phenotypic) variation within a species
–> important for surviving disturbances, variable environments
19
Q
phylogenetic diversity
A
diversity of unique evolutionary lineages within an area
–> species, genera, families, etc.
20
Q
life history evolution
A
strong selection can rapidly alter life history traits
–> e.g. Northeast Arctic cod have been shifting to earlier reproductive maturity because human fishing selects against size, which correlates with age
21
Q
evolutionary framework: clownfish
A
Xi + riYi > Xj + rjYj
–> Xi or Xj = fitness of nonbreeder
–> Yi or Yj = breeder’s fitness associated with nonbreeder’s actions
–> r = probability of sharing allele by descent
–> i = payoff from staying
–> j = payoff from leaving
22
Q
Lotka-Volterra: mutualism
A
species 1 isocline: N1 = a1,2N2 + K1
species 2 isocline: N2 = a2,1N1 + K2
23
Q
ecological constraints in clownfish
A
predicts: individuals stay as non-breeders when there is some ecological constraint and likelihood of dispersing increases when that is relaxed
–> anemone habitat is saturated; movement between is risky
–> created vacancies by removing non-breeders or breeding males; no individuals dispersed whatsoever
–> alternative anemone placed 0.5m away: 1/32 non-breeders dispersed
–> non-breeders moved to anemone 0.5m away from home: returned in 21/32 cases
–> non-breeders moved to anemone 5m away from home: none returned (too far)
24
Q
reasons for sexual selection
A
–> large gametes (eggs) require greater energy investment per reproductive event
–> gestation/egg laying costs are usually borne by the female
25
why do breeders tolerate non-breeders? hypotheses
1. breeders cannot evict non-breeders: false - they can and do evict if they get too large
2. breeders accrue direct benefits: false - no effect
3. breeders accrue indirect benefits: maybe distantly related?
--> might reduce variance in reproductive success (bet-hedging)
4. breeders accrue mutualist benefits: maybe non-breeders enhance anemone fitness?
26
disturbance regimes
timing, extent, intensity of disturbances within a given area
--> some have many small-scale, low-intensity; others fewer, large-scale, high-intensity
--> leads to intraspecific variation
27
why would animals help each other, forgoing their own reproduction?: ecological constraints
alternative options to being a breeder:
--> stay on natal territory as non-breeder
--> disperse from natal territory to breed elsewhere
--> contest to breed on natal territory
28
population cycles
r & K are determined by other ecological factors (e.g. presence vs lack of a predator/prey)
--> delayed density-dependance
29
carbon cycle process: step 2
heterotrophic respiration
--> microbes: 44 Pg C/yr (decomposition)
--> herbivores: 3 Pg C/yr
30
kin selection in clownfish
year long study, 97 groups: monitored 71 groups and removed non-breeders from 14
--> found: non-breeders do not enhance survival, growth, or reproductive success of breeders
--> non-breeders are not closely related to breeding pair
31
adaptions in predators
evolutionary arms race; enhances predation rate or capture efficiency
--> camouflage, heightened sensory capabilities, aggressive mimicry
32
carbon cycle process: ocean
ocean at approx. equilibrium with atmosphere (NPP = 51 Pg C/yr, exchange of CO2)
--> currently takes up slightly more CO2 than emitted (sink)
--> organic matter, biogenic carbonates sink to seafloor; store carbon in sediments over deep time (carbon sequestration)
33
sampling effect (species identity effect)
counterargument to higher ecosystem function as a result of higher biodiversity
--> a more diverse community is just more likely to include the specific species most important for that function
34
life history trade-offs
time, energy, nutrients allocated for one purpose are unavailable for others = costs
--> current repro = lower survival, future repro
--> current growth = lower or delay in repro
--> investments in defense = lower growth, repro; may never be realized
35
mutualism: need classifications
facultative: species can live without their partner
obligate: species are dependent, cannot live without partner
--> can be facultative for one partner and obligate for the other
36
future selection in clownfish
predicts that nonbreeders will inherit territory upon death of breeders, fi > 0
--> year long study, 97 groups; monitored natural vacancies in 57 groups and created them in 16
--> found: largest non-breeder from anemone inherited vacancy; never did a non-breeder from another anemone usurp
37
Lotka-Volterra: mutualism - lines start at K1 and K2 > 0, increase and intersect OR facultative with a < 1
stable facultative mutualism
--> both species achieve stability where the isoclines cross
38
case study: do or do not denitrification?
each step of denitrification produces less energy, with its own associated enzymes; complete = N2 or incomplete = N2O
case study: early-successional old field vs cropped farm field
--> incomplete denitrification favored in cropped soil, watered + fertilized simultaneously (must be waterlogged)
--> cropped soils contained more microbes adapted to higher nitrate availability
39
carbon cycle process: step 3
fossil fuel emissions, cement production
--> 10 Pg C/yr
biomass burning
--> 2.5 Pg C/yr
40
Lotka-Volterra State Space: competition
models stable population levels: population sizes that can be maintained over time (set dN/dt = 0)
--> species 2 isocline: N2 = -aN1 + K2, so intersects N2 at K2 and N1 at (K2/a2,1)
--> if combined population is below isocline, population will move up; if above, move down until at isocline or extinct
--> species 1 isocline: N1 = -a*N2 + K1 so intersects N1 at K1 and N2 at (K1/a1,2)
41
Simpson Index
D = sum(pi^2)
--> probability that any two successive samples with replacement will produce the same species
--> lower D = more diverse
42
carbon cycle measurements
pools measured in Pg C (petagrams of carbon)
fluxes measured in Pg C/yr (petagrams carbon per year)
--> 1 petagram = 1 gigaton (1 billion metric tons)
43
asexual reproduction
first, only mode of reproduction for billions of years
--> passes on 100% of genes
--> no need to find a mate
--> risky in variable environments
--> e.g. "budding"
44
case study: jack pine cones
compared cone closure between mainland (rare, intense fires) and island (frequent, mild fires) jack pine populations
--> serotinous trees with closed cones are more flammable; non-serotinous trees resist fire, grow thicker bark, drop lower branches
--> result: mainland had less quasi-non-serotinous, more serotinous trees vs. islands (islands learned to resist fire)
45
ecosystem services
benefits people get from ecosystems (quantifiable dollar amount)
--> provisioning: food, water, resource
--> regulating: maintenance of stable ecosystem processes
--> cultural: fostering creativity, cultural development, recreational/spiritual fulfillment
--> supporting: basal services to support provision of others
46
kin selection
natural selection in favor of behavior that may decrease chance of survival, but increase that of kin
--> r for offspring: 0.5
--> sibling: 0.5
--> half-sibling: 0.25
--> nibling: 0.25
--> cousin: 0.125
47
criticism of diversity indices
do not measure the scale of difference between two populations
48
population
group of organisms of the same species living in the same place at the same time
--> breeding pool: possibility of interaction
49
biological nitrogen fixation
nitrogenase enzyme = responsible for most nitrogen in living biomass today
--> extremely energy-intensive process
50
Lotka-Volterra: competition - K1 > (K2/a2,1) and K2 > (K1/a1,2)
both are more limited by competition with each other: unstable equilibrium where either could drive the other to extinction if they move away from that point
51
intermediate disturbance hypothesis
diversity will be higher at intermediate levels of disturbance, rather than high (only most resistant species survive) or low (competitive dominants exclude others)
52
Lotka-Volterra predation assumptions
1. growth of prey population is limited only by predation (no carrying capacity)
2. individual predators can consume an infinite number of prey
3. predator and prey encounters occur randomly in homogeneous environment (no refuges)
4. predator is a specialist, will starve without prey (no switching)
5. no immigration or emigration
53
population growth equation
dN/dt = rmax*N*[1-(N/K)]
--> rmax = intrinsic rate of increase
--> N = pop size
--> K = carrying capacity
54
mutualism helps by:
increasing diversity, stability, and function
--> promotes complex networks
--> enhances stability; species diversity (positive feedback); support for higher abundances; co-existence (decreased competition)
55
primary succession
initial pioneer species must build up new soil
--> occurs after severe disturbance (intense landslide, volcanic eruption, severe flood/fire)
--> occurs when new land is formed/exposed (e.g. glacial -> provides a chronosequence to watch similar environmental conditions which differ in age)
56
late-successional species (K)
low reproductive output
low or non-random dispersal
slow-growing
shade-tolerant
57
case study: niche complementarity
four insect pathogens (1 fungus, 3 nematodes) on Colorado potato beetle
--> more diverse pathogen communities = higher mortality
58
life history
dictated by evolved characteristics
--> compilation of quantitative measurements regarding typical outcomes of growth, reproduction, survival
--> phenotype: subject to selection and can be plotted
59
residence time
average amount of time a single molecule spends in a given pool
60
clownfish societies
--> groups closely associated with sea anemones
--> each group composed of a breeding pair and non-breeders
--> within each group, a size-based dominance hierarchy
--> female largest, male second largest, non-breeders smaller
--> sequential hermaphrodites: male > female
--> breeding year-round on lunar cycle
61
Jamaican bromeliad crab
high parental care in order to protect young
--> predators: murder
--> anoxia: cleaning and pick out decaying organic matter
--> low pH, low calcium content: place snail shells into nursery pools
62
sexual reproduction
selected for by variable environments
--> gametes created through meiosis, passing on 50% of genes
--> recombination during meiosis = genetically variable gametes
--> fertilization (combination of gametes) produces viable offspring
63
anisogamy
gametes of different sizes
--> almost always 2 (small and large), requiring small to fuse with large
--> e.g. sperm fuses with ovum/egg
64
sociality
degree to which animals live together and cooperate with each other
65
selection for mating systems: monogamy
biparental care
66
indigenous fire management
practices informed by Traditional Ecological Knowledge (TEK)
--> often linked with cultural practices
--> Good Fire: fire is an agency with intentional action upon land; burning practices seen as a duty, used wisely
--> growth of fire ecology
67
Lotka-Volterra: interspecific competition
dN1/dt = rmax1*N1*[(K1-N1-a1,2*N2)/K1]
dN2/dt = rmax2*N2*[(K2-N2-a2,1*N1)/K2]
where a = competition coefficient; a1,2 = effect of species 2 on species 1
--> if a1,2 = 2, species 1 feels that interacting with 1 individual from species 2 is the same as interacting with two of their own
68
ecological succession: whale fall
new substrate introduced to ecosystem when carcass of whale (or other large organism) reaches sea floor
1. scavenger: carcass eaten by mobile scavengers (sharks, fish, crabs)
2. enriched sediment stage: sediment, with nutrients, supports invertebrates
3. sulfide stage: sediment becomes anoxic, emits hydrogen sulfide; supports chemoautotrophic bacteria and invertebrate hosts
4. reef stage: bones provide hard substrate for epibenthic organisms
69
adaptions to fire
pyrophytes: plants adapted to tolerate fire and/or require fire to germinate
--> e.g. jack pines have serotinous cones, which only open with intense heat
70
life history example: plant seeds
larger seeds = larger seedlings = higher survival, BUT fewer seeds if larger
71
effective number of species (ENS)
ENS = exp(H) for Shannon; this community is as diverse as a community with X equally abundant species
ENS = 1/D for Simpson; ""
72
life history plot
growth and development trait = x axis
reproduction trait = y axis
survival trait = z axis
73
natural selection
for or against a trait based on survival and reproduction
--> judged against others of the species
74
Lotka-Volterra competition: K1 < (K2/a2,1) and K2 < (K1/a1,2)
stable coexistence: species will always reach and stay at/around a stable equilibrium
75
population structure
populations structured by age, size, life cycle stage
--> survival and reproduction rates vary by stage
76
geological carbon cycle
rock weathering consumes CO2, releases bicarbonate (HCO3-) to oceans
--> HCO3- taken up by marine life, settles to bottom, becomes rock
--> rock eventually subducted, erupted (releasing carbon)
77
interaction: +, -
exploitation
78
Shannon Index
H = -sum(pi*ln(pi))
--> pi = proportion of species i in community
--> level of uncertainty in the species identity of any sampled individual
--> higher H = more diverse
79
sexual dimorphism
correlation between gamete size and other phenotypic differences, including:
--> color
--> size
--> ornamentation
--> weaponry
--> behavior
80
oceanic islands biodiversity
NOT higher like other tropics; hard to disperse there
81
exploitation
exploiter gains resources (energy, nutrients), enhancing its fitness while the victim suffers reduced survival/reproductive success
--> predation: predator (+), prey (-), victim always dies
--> herbivory: herbivore (+), plant (-), victim rarely dies
--> parasitism: parasite (+), host (-); parasitoid and parasite have victim rarely die, pathogen depends
82
problem with mutualisms
some seemingly mutual relationships are not - oxpecker birds are more parasitic than it seemed, as they will consume blood from open wounds and eat earwax if necessary
--> however: also help warn rhinos of approaching humans
--> cheating: bacterial strains will form nodules in plants (helpful) BUT stop fixing nitrogen after enough are made
83
ecological succession
gradual change in community composition of an area following
--> creation of new substrate (primary)
--> disturbance of prior community (secondary)
84
Lotka-Volterra predation models: predator
dN/dt = b*a*NP - MP
a = predation rate
N = prey pop
P = predator pop
b = predator birth rate
m = predator mortality rate
dP/dt is positive if baN > m
85
life history example: mammals and primates
mammals: bigger litter (n) = smaller offspring
primates: later maturation = larger offspring (early maturity = limited physical capacity)
86
global patterns of nitrogen fixation
performed by free-living, root-symbiotic microbes
--> most prevalent in tropics
87
synergistic effect
something may perform poorly alone, but enhance the effects of other multispecies communities
88
natural disturbance as a selective force
floods, droughts, landslides, avalanches, storms, insect outbreaks
--> if seasonal, periodic, or episodic, adaptations can be selected for to withstand; not if random (e.g. earthquake or volcano)
89
mutualism example: Cleaner Wrasse
fish that removes dead tissue, ecto-parasites, infected tissue from wounds of "client fish" --> eats in return
--> helps those cleaned not have to mount an immune response against the parasites, which costs a lot of energy (seen when mutualist is removed)
90
sociality: subsocial
mates and cares for own offspring, but no association with other adults
91
Lotka-Volterra competition: K1 < (K2/a2,1) and K2 > (K1/a1,2)
species 1 is always driven to extinction: 1 competes more with itself than with 2, but 2 competes more with 1 than with itself
92
secondary succession
existing organisms killed, soil intact
--> not always clean and predictable: mosaic of different successional stages promotes biodiversity
93
survivorship curves
plot of survivorship over the lifespan of species
--> Type 1: high juvenile survival, most individuals reach max age (mostly large mammals - human)
--> Type 2: survival rates even throughout lifespan (birds, reptiles)
--> Type 3: low juvenile survival (fish, marine invertebrates, plants with many seeds)
94
strong selection: adaptions in prey
camouflage
intimidation
mimicry
95
interaction: -, -
competition
96
carbon sequestration results: niche complementarity
mixtures with legumes and C4 grasses stored more carbon than those without
--> C4 = higher root biomass, as roots decompose slowly
--> legumes = nitrogen to soil via fast-decomposing roots, which fertilize C4 grasses to increase growth
97
population sampling: indirect
along a transect (proxy)
catch per unit effort
98
nitrogen cycle
atmosphere N2 >> N fixation >> litter/SOM (organic N) >> plants (organic N) >> ammonification NH4+ >> immobilization or nitrification NO2- >> nitrate NO3- >> leaching = into deeper soil, dentrification into NO2-/NO/N2O/N2 >> nitrogen dioxide NO2 = acid rain >> back to atmosphere
--> nitrate > nitrite > nitric oxide > nitrous oxide > nitrogen gas
99
life history: r selection
species adapt to maximize in low-density environments
--> life history maximizes growth, reproduction
--> early maturity; high number of offspring; small parental investment; short generation time
100
life history: K selection
species adapt to survive at or near K (high density)
--> late maturity; low number of offspring; large parental investment; long generation time
101
monogamy
individuals mate exclusively with one partner
102
population sampling: mark-recapture
capture, mark, release individuals; recapture and extrapolate total population based on number of marked in sample
--> assumes that pop size does not change between surveys; marks are never lost; marks do not affect survival; marked individuals redistribute randomly; all individuals are equally likely to be captured
103
parental care: for both parents to care
M: SP2 > SP1 + mSP1
F: SP2 > LP1
104
sociality: parasocial
cohabitation but care mostly for own or related young
105
social constraints in clownfish
predicts: individuals will wait as non-breeders given some social constraint, and likelihood of contesting increases when disrupted
--> subordinates are 80% size of immediate dominants; prob of subordinate winning a contest is close to 0
--> removed non-breeders from 16 anemones, introduced larger or smaller non-breeders
--> larger non-breeders contested, were evicted 12/16 times
--> smaller non-breeders contested 3/16 cases
106
case study: forest tent caterpillar
use natural predators as a means to combat outbreaks, even though caterpillars accumulate indigestible calcium oxalate
--> cuckoo bird: sheds stomach lining
--> black bear: doesn't care
--> parasitoid: lays eggs inside
--> caterpillar booms lead to population booms of the parasite (friendly fly)
--> drivers of outbreak: climate, forest structure (density-independent) and natural enemies (delayed density-dependent)
107
evolution of carbon cycling traits
carbon fluxes are mediated by organisms' traits, which are subject to natural selection
--> behaviors of photosynthesizers have evolved and will continue to evolve
108
interaction: 0, -
amensalism (probably doesn't exist)
109
why would animals help each other, forgoing their own reproduction?: kin selection
individuals can pass on genes:
--> directly (own offspring)
--> indirectly (enhancing offspring production of relatives)
--> directly by producing own offspring in the future
110
intersexual selection
traits increasing attractiveness to the opposite sex
111
measuring diversity
transects: sample at/from points along a line
quadrats: count individuals or measure percent cover within square of defined area (1 m2 or 0.25 m2)
112
case study: evolution of carbon cycling
green algae raised in freshwater mesocosms at ambient vs. warmed temps for 10 years
--> warmed isolates evolved higher optimal temperature ranges, higher net photosynthesis rates
113
population growth: exponential
dN/dt = rmax*N
114
promiscuity
individuals from both sexes mate with multiple partners
115
polygamy
individuals of one sex mate with more than one partner
116
interspecific competition
competition between different species
--> typically over food (overlapping niches)
117
benefits of sociality
--> shared vigilance
--> sharing warmth
--> safety in numbers
--> cooperative feeding
118
selection for mating systems: polygyny
one male, multiple females
--> resource controlled by a dominant male competitor
119
simultaneous hermaphroditism
produces both gamete sizes at once
--> e.g. earthworms, slugs, most plants
--> low density hypothesis: finding a single other organism is enough to reproduce
--> self-fertilization is possible but may lead to inbreeding depression
120
parental care evolution
when benefits outweigh costs
--> when increased offspring survival is greater than time and energy investment, missed mating opportunities
--> not seen in most species, but seen throughout the animal kingdom
121
Lotka-Volterra: mutualism - lines start at K1 and K2 > 0, increase without intersecting OR facultative with a >/= 1
runaway facultative mutualism
--> both species will increase in abundance "forever" until something else stops them
122
Lotka-Volterra: competition - K1 > (K2/a2,1) and K2 < (K1/a1,2)
species 2 is always driven to extinction: 2 competes more with itself than with 1, but 1 competes more with 2 than with itself
123
niche complementarity
different species specialize to perform roles in different ways, together do a more thorough job
--> two species may perform the same job, but are not interchangeable; each does a diff subset of the task
124
plants and fungi: mutualism
80-90% of plant species are mycorrhizal
--> fungi connect to plant roots, improving nutrient and water uptake in exchange for carbon
--> mycorrhizal symbionts facilitated initial colonization of land by plants
--> greater phylogenetic diversity
125
parental care: for only the male to care
M: SP1 > SP0 + mSP0
F: LP1 > SP2
126
sequential hermaphroditism
shifts from producing one gamete size to the other at one or more points
--> e.g. reef fish, slipper snails
--> size advantage hypothesis: switch to enjoy optimal size for each sex
--> inbreeding avoidance: keeps siblings from reproducing (since they are the same size at the same time)
127
mutualism
interactions between different species that benefit both partners
--> very common, found virtually everywhere: plants and fungi, plants and animals, between animals
--> classified by type of service provided and by need
128
logistic growth: intraspecific competition
[(K-N)/K] = [1-(N/K)]
129
mutualism: service classifications
categorized based on types of service provided
--> nutrients, food, shelter, transport, cleaning, protection, reproduction assistance
--> partners may exchange the same or similar services, or each provides a different service in exchange for another
130
inclusive fitness
an individual's survival and reproduction + survival and reproduction of relatives (who share alleles)
131
evolution of anisogamy
diversifying selection for gametes which are:
--> small, cheap, mobile (sperm)
--> large, energy rich (egg)
as these traits increase survival/reproductive ability
132
interaction: 0, 0
neutrality (probably doesn't exist)
133
interaction: +, +
mutualism
134
transformation
change of an element from one chemical form to another, within or between poolls
135
how to quantify biodiversity
richness + evenness measured in diversity indices (single numbers for comparison)
136
flux
quantity of an element moved from one pool to another in a given time
137
biogeochemistry
study of elemental cycles on molecular to global scales
--> world sustains itself on the same atoms, over and over again
138
intraspecific competition
competition between individuals of the same species
--> increases in intensity when N approaches K
--> strong comp over mates
139
future selection framework
Xi + fi*Zi > Xk + fk*Zk
--> Xi or Xk = nonbreeder's present fitness
--> Zi or Zk = nonbreeder's future fitness
--> f = probability of realizing benefits in the future
--> i = staying
--> k = contesting
140
Lotka-Volterra state space: predation
--> N = 0, P = rmax/a and then P is a horizontal line as N increases
--> P = 0, N = m/ba and then N is a vertical line as P increases
--> leads to predator-prey cycles: bottom right > top right > top left > bottom left, synchronized but out of phase (with lag)
1. bottom left: prey recover as predators are scarce >>>
2. bottom right: predators recover as prey become abundant >>>
3. top right: predators overexploit prey, prey starts to decline >>>
4. top left: prey crash, predators start to decline >>> cycle
141
mutualism: population growth
dN1/dt = rmax1*N1*[(K1-N1+a1,2*N2)/K1]
dN2/dt = rmax2*N2*[(K2-N2+a2,1*N1)/K2]
a = mutualism coefficient: presence of one species increases carrying capacity of other
142
alternative reproductive tactics (ARTs)
diversifying sexual selection leading to dimorphism within sexes
--> e.g. salmon: hooknose vs. jack males, where jack are smaller and less attractive but mature faster for reproduction
143
carbon cycle
process of carbon moving between atmosphere to living organisms, (biosphere) into land, (fossil fuels) and to ocean
--> involves fast processes (photosynthesis) and slow (rock weathering)
144
ecology of fear: case study
fear of predators in free-living birds = reduced population growth over generations (only the sound, even in caged nests)
--> fear raises stress hormone levels (cortisol), associated with negative impacts on health and fitness
--> fear impedes neurogenesis: traumatic memories persist in the brain, antipredator behaviors may persist longer (more vigilance, less foraging), animals get PTSD
145
Lotka-Volterra: mutualism - lines start at K1 and K2 < 0, increase without intersecting OR obligate with a < 1
collapsing obligate mutualism
--> both species are doomed: cannot support each other enough to survive
146
selection for mating systems: polyandry
one female, multiple males
--> rare; occurs when females invest less energy per reproductive event than males
--> e.g. jacanas, where males provide care; or field crickets, where males provide nuptial gifts
147
interspecific competition and coexistence
competitive exclusion principle: two species with identical niches cannot coexist indefinitely, more competitive species will drive the other to local extinction
--> ability to coexist depends on relative degree of intra vs. interspecific competition
148
Lotka-Volterra predation models: prey
predation prevents prey from reaching K, dropping [(K-N)/K] term
--> dN/dt = rmax*N - aNP
a = predation rate/capture efficiency
N = prey population
P = predator population
149
territory
area in space that an individual or group consistently defends (inter- or intra-specifically)
--> territoriality evolves when benefits > costs of controlling
--> visual, auditory, scent signals
150
functional diversity
diversity of functionally different species within an area
--> wind-dispersed vs. animal-dispersed trees; diurnal vs. nocturnal pollinators; nitrogen fixing vs. denitrifying
--> fill different roles in the ecosystem
151
Hamilton's Rule
individuals of the same species should help each other when...
rB > C
--> r = genetic relatedness of helper and helped
--> B = reproductive benefit gained by helped
--> C = reproductive cost incurred by helper
152
species evenness
relative abundance of comparable species
153
isogamy
gametes are all of equal size
--> sometimes, gametes must be of different "sex" to fuse
--> common to have 2-10 mating types (sexes), but some species have more than 1,000
154
ecology of fear
total impact of predators on prey populations
--> fear of predation causes sublethal, sometimes lethal effects on prey
--> reductions in growth, fecundity, survival
--> altered behavior/habitat use (with larger implications)
155
gonochorism
each individual produces one size of gamete
156
drivers of biodiversity
--> climate: speeds up metabolism, growth, reproduction, evolution
--> productivity: more resources available = more needs met = lower competition (exclusion)
--> topography: more variable = more niches
--> climate history/age: tropical rainforests are the oldest terrestrial biome
--> ecology: biodiversity begets biodiversity
157
sociality: eusocial
stratified society with:
--> overlapping generations
--> cooperative brood care
--> reproductive division of labor
--> behavioral differentiation among workers
158
sexual selection
for or against a trait based on mating success
--> judged against others of the same sex within the species
159
sociality: solitary/presocial
independent except for when mating
160
carbon sequestration: sampling effect
NOT TRUE
--> found: higher-diversity polycultures performed better than the best monoculture
161
pool
quantity of an element contained within a part of the earth system (e.g. organic C)
--> aka stock, reservoir
162
carbon cycle process: step 1
photosynthesis and plant respiration
--> global GPP = 123 Pg C/yr, approx 50% to plant
--> 60-70 Pg C/yr NPP
NPP split evenly above and belowground
--> most NPP becomes litter; 25-30 Pg C/yr above, 25-30 Pg C/yr belowground
163
parental care: game theory
model can be used to determine what conditions have to be true for different parental arrangements to be selected for/against
--> P0: survival with 0 parents
--> P1: survival with 1 parent
--> P2: survival with 2 parents
--> m: probability that leaving male finds second mate
--> L: number of offspring female can have if she leaves, finds another mate
--> S: number of offspring a female can have if she stays and cares
BI303 - Evolutionary Ecology
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