Evolution and Ecology Flashcards
The entirety of Sem 2 (111 cards)
1
Q
What is evolution?
A
The total environment determining the reproductive success and survival of species, leading to change in allele frequency.
2
Q
What are the 5 ways we study ecology?
A
- Observation
- Surveys
- Correlations
- Experiments
- Models
3
Q
What is a metapopulation?
A
A single population that occurs in fragmented habitats connected by limited migration. Lots of extinction and recolonisation.
4
Q
What is the Lincoln Index equation?
A
N = M (Marked individuals released) x S (Size of second sample / R (Marked animals recaptured)
5
Q
What is a stressor?
A
An environmental factor that inhibits growth and reproduction.
6
Q
What is stress?
A
The physiological resultant of demands that exceed an organisms capacities.
7
Q
What is Shelford’s Law of Tolerance?
A
Species distribution is controlled by the factor which the species has the narrowest range of tolerance too.
8
Q
What law is Shelford’s law based on?
A
Liebig’s law of minimum, stating that the rate of biological process is limited by the factor in the least amount.
9
Q
What is acclimation?
A
A response by an animal or plant that enables it to tolerate a change in a factor in its environment.
10
Q
What is acclimatisation?
A
Reversibly adaptive response that enables animals or plants to tolerate environmental change involving several factors (E.g. Hibernation)
11
Q
What is adaptation?
A
Evolutionary processes through natural selection that changes the tolerance of a species.
12
Q
What is the epilimnion?
A
Warm, low density surface waters.
13
Q
What is the thermocline?
A
Zone of rapid temperature change in water.
14
Q
What is the hypolimnion?
A
Cold high density deep water.
15
Q
What is the proximate study of a trait?
A
How the gene works and how it is achieved. Mechanism that underpins the trait and explaining the biological function (like genes)
16
Q
What is the ultimate study of a trait?
A
The consequences of a trait and if it is selected. Study of traits in terms of the evolutionary forces acting on them. (Such as colour for poison)
17
Q
What did Jean Baptiste Lamarck believe in?
A
- Traits and behaviours change (correct, evolution)
- Moving to human perfection (incorrect, self explanatory)
18
Q
What is fitness?
A
Measure of an organisms ability to produce viable offspring in comparison to others.
19
Q
What are the three types of selection?
A
- Directional
- Disruptive (can cause adaptive radiation)
- Stabilising
20
Q
What is the equation for total phenotypic variance?
A
Vp= Vg + Ve
g = variance due to genetic effects
e = variance due to environment
21
Q
What is heritability of a trait?
A
The proportion of observable differences between individuals within a population due to genetic differences.
22
Q
What is the equation for heritability?
A
Vg/Vp
23
Q
What is Mendel’s first principle?
A
‘Principle of Segregation of Unit Characters’
- 2 of more phenotypes conferred by the same gene are an allele.
24
Q
What was Mendel’s second principle?
A
The principle of independent assortment.
25
What are the two types of variation?
Continuous: Many genes, high environmental influence and no discrete morphs (leaf size)
Discontinuous: few genes with low environmental influence. Few discrete morphs (patterns on spider bodies)
26
Give a summary of the Cambrian explosion.
- 565 mya, marked by the first tracks of bilaterian.
- All major phyla appear
- First stage of the Phanerozoic
There is a possibility that there were diverged phyla beforehand and the explosion is due to a change in bio/marine chemistry that led to fossilisation.
27
What are some of the biological causes of an extinction?
Being outcompeted by another species, disease.
28
What are some of the non biological causes of an extinction?
Asteroids, any change in abiotic factor, tsunamis and earthquakes, volcanic eruptions, change in the atmosphere, water levels changing.
29
What are the big 5 extinctions?
Cretaceous, Triassic, Permian, Devonian, Ordovician.
30
Name the date, impact, and cause of the Ordovician extinction.
Date: 439 mya (440)
Impact: Extinction of 1/4 of marine families (Bivalves, echinoderms, corals, trilobites)
Cause: Decrease in sea levels due to glacial formation
31
Name the date, impact, and cause of the Devonian extinction.
Date: 364 mya (360)
Impact: Extinction of 1/5 of marine families (Trilobites, ammonites, reef builders)
Cause: Unknown
32
Name the date, impact, and cause of the Permian extinction.
Date: 251 mya (250)
Impact: Extinction of 95% of all species (Ammonites, trilobites X_X, echinoderms, insects, brachiopods)
Cause: Volcanic eruption/asteroid
33
Name the date, impact, and cause of the Triassic extinction.
Date: 207 mya (200)
Impact: Extinction of 1/2 of marine families (conodonts X_X, reptiles, amphibians)
Cause: Undersea volcanoes
34
Name the date, impact, and cause of the Cretaceous extinction.
Date: 66 mya
Impact: Dino's dead, extinction of 1/2 of major groups of marine species (ammonites X_X, dinosaurs X_X (other than birds), pterosaurs X_X, plesiosaurs X_X, plants)
Cause: Asteroid
35
What is coevolution?
A change in one gene in a species stimulates an evolutionary change in one gene in another species. This causes another change in the first species and the cycle repeats.
36
What are the two types of coevolution?
Mutualism - Both benefit
Commensalism - One benefits, the other doesn't lose.
37
What are the three types of coevolution that does not result in an arms race?
Plants and:
1. Pollinators
2. Dispersers
3. Herbivores
38
What are the two types of coevolution that result in an arms race?
1. Hosts vs parasites/pathogens
2. Prey and predators
39
Describe the Red Queen Hypothesis.
To evolve as a species, the prey must be constantly evolving so that the predator can never catch it.
40
Describe the sequence of an arms race.
1. Parasite reduces fitness of host
2. Host increases fitness via mutation/recombination, and this trait spreads
3. New mutant/recombination appears in parasite species, spreads in population.
41
What types of mutation might occur in an arms race?
1. Colouration change
2. Protective armour
3. Chemical defence
4. Mimicry
5. Behavioural change
42
What are the three types of defensive colouration?
Cryptic: Blending into the background
Masquerade: Object resemblance, distracting attack away from most vulnerable part
Aposematic: Bright, 'oh shit thats poison' colours
43
What are the two types of mimicry?
Batesian: Both species toxic, reinforced message.
Mullerian: One is toxic, the other isnt.
44
What are some behavioural mutations that may occur in an arms race?
Deimatic (Intimidating), Thanatosis (fake death), Retaliation, Fleeing
45
What are the two types of chemical defence?
Unapparent: Simple chemical, immediate deterrent.
Apparent: Complex indigestible compounds, long term avoidance.
46
What is deimatic behaviour?
Defensive postures or visual displays intending to frighten or intimidate others. Like pufferfish going from :o to :O
47
Describe the use and assumptions of the geometric population growth model.
For annual breeders. Assumes:
- Birth rate > death rate
- B/D rates independent of population size
48
Describe the use and assumptions of the exponential population growth model.
For species with continuous reproduction including bacteria, protists and humans. Assumes:
- No immigration/emigration
- No death due to predation/competition
- Population changes only due to B/D rate
49
Describe life history theory.
Many physical and behavioural traits are best understood in the context of the characteristics of a species. E.g. gestation period, litter size, body size etc.
50
What is semelparity?
Very high reproduction rates with little effort (R selected species)
51
What is iteroparity?
Few young with high levels of parental care (K selected)
52
What is monogamy?
Partners with biparental care. They in love. They lobsters.
53
What is promiscuity?
Everyone mates with everyone. No postnatal care. Metal.
54
What are the different types of polygamy?
Polygyny: Male is polygamic
Polyandry: Female is polygamic
Uniparental care, dependant on whoever isn't polygamic.
55
What are the four mechanisms that maintain genetic diversity?
1. Populations not being in an equilibrium with directional/stabilising selection
2. Deleting mutations and selection is balanced
3. Disruptive selection is common
4. Flow of genes between populations
56
Why is disruptive selection common?
1. It is frequency dependent selection
2. Occurs in a fluctuating environment
3. Hetero/homozygous advantage
57
What is a population viability analysis (PVA) ?
Estimation of probability of persistence or extinction over a specific time period.
58
What are 4 ways humans are changing habitats?
1. Habitat degradation and destruction
2. Habitat fragmentation
3. Overexploitation
4. Introduction of non native species
59
Are metapopulations more or less likely to go extinct than individual local populations? Why?
Much less likely (60% less in a study from 2001) as they have larger and more diverse populations due to immigration and more space.
60
Describe the Allee effect.
Social dysfunction and failure to mate that occurs in some species when their population falls below a certain threshold, such as at a low density.
61
Describe the Enemy Release Hypothesis.
1st hypothesis on why non native species are so successful:
- They can disperse with none of their natural enemies to keep them in their range.
62
Describe the Evolution of Increased Competitive Ability (EICA) Hypothesis.
2nd hypothesis on why non native species are so successful:
- Fewer herbivores mean they can allocate resources to survival and reproduction, increasing competitive ability.
63
Describe the Resource Hypothesis.
3rd hypothesis on why non native species are so successful:
- They experience an ideal combination of resources than they do in their native habitat.
64
Why is gigantism and dwarfism common on islands?
Island fauna is impoverished, and there may be only a few species who have managed to make it onto the island. This means it may lack a normal predator or competitor.
65
What is the z value indicative of in Species-Area relationships?
High z value: Species richness increases rapidly with area
Low z value: It increases gradually with area
66
What is a landscape?
An area spatially heterogenous in one factor of interest.
67
What is the matrix in landscape ecology?
The area surrounding suitable habitats. Movement between fragments depends on the quality of the matrix.
68
What is an ecological trap?
A proposed situation in which organisms are induced to settle in a low quality habitat that has been made to appear more attractive than the actual habitat quality.
69
What is a community?
A grouping of populations of different organisms living together in a particular environment.
70
What is a guild?
A group of species that all exploit a similar resource in a similar fashion.
71
What is relative abundance?
What % of each species contributes to the total number of individuals of all species.
72
What is the Intermediate Disturbance Hypothesis?
A hypothesis that predicts that species diversity will be highest at intermediate levels of disturbance. Too high reduces the species able to live there and too low allows competition to reduce diversity.
73
What is zonation?
The division of an ecosystem into distinct layers that experience similar abiotic conditions.
74
What is the 2nd law of thermodynamics?
In a closed system, entropy (chaos) will always increase. We don't do this because we are not closed off, getting energy from the sun.
75
What is productivity?
Rate in productivity in kcal, m2 etc etc a year.
76
What is standing crop biomass?
Amount of accumulated organic matter in an area at a given time. Peat bogs have high SCB but low productivity.
77
How do you calculate Net Primary production?
(Increase in living plant biomass) + Death + Biomass in consumer organisms
78
What is the Eltonian Pyramid?
The pyramid of dry weight along the trophic levels. Producers have lots and it very very quickly decreases along the consumers. Its not a very good pyramid.
79
What is a nutrient pool?
The amount of nutrient that is stored in a particular part of the ecosystem.
80
What is nutrient flux?
The rate at which a nutrient moves between different pools.
81
What is a nutrient source?
A nutrient pool where a nutrient is released faster than absorbed. Opposite is a nutrient sink.
82
Describe the phosphorous cycle.
Rocks and soil →(decomposition) → Run off lakes/streams → (inorganic phosphate) → absorption by plants→ PO₄³⁻ → Consumption/metabolism → ATP → Decomposition → Rocks and soil
83
What does decomposition release?
Energy
Carbon dioxide
Water
Inorganic nutrients
84
What is the order of size of flora/fauna? (smallest to biggest)
Micro (<100μm) - bacteria, fungi, protozoans etc
Meso (100μm-2mm) - springtails, mites etc
Macro (2-20mm)
Mega (>20mm) - snails, molluscs etc
85
What four factors affect decomposition?
Moisture (More = less decomp)
Temperature (More = more decomp)
Chemical composition of : Substrate and environment (More soluble phosphorus = more decomp)
86
What are the three stages of nitrogen in leaf litter?
1. Leaching = Organic N decreases as water soluble compounds are lost
2. Mineralisation = Organic N → Inorganic N
3. Immobilisation = Organic N increases as inorganic N is taken up by decomposers.
87
How is net mineralisation calculated?
Mineralisation - immobilisation
88
What is the typical growth pattern of early species in succession?
- Fast growth
- High dispersal
- Short lived
89
What is the typical growth pattern of late species in succession?
- Low growth rate
- Low dispersal
- Long lived
90
Describe the basic pattern of succession.
1. Each new community creates a new niche
2. New niche occupied by new species
3. Old species are outcompeted and die or their niche disappears and they die
91
What is cyclical succession?
When succession occurs, reaches a climax community, a disturbance occurs and everything goes back to the beginning.
92
What is the difference between stochastic and deterministic?
Deterministic - Models based on precise inputs/outputs, knowing exactly the outcome.
Stochastic - Models predicting an outcome incorporating randomness and uncertainty.
93
What are the four disturbance regimes in the Intermediate Disturbance Hypothesis?
A - No disturbance (Div = 1)
B - Frequent small-scale disturbance (Div=1.6)
C - Infrequent small scale disturbance (Div= 4)
D - Infrequent large scale disturbance (Div=1)
94
What is facilitation and the two types of it?
Interactions between organisms that benefit at least one of them and harms neither.
Both benefit = Mutualism
One benefit = Commensalism
95
What is mutualistic symbiosis?
Host and parasite both benefit.
- Plants and pollinators
96
What is commensalism? (Symbiosis type)
Parasite benefits from relationship, but host is not harmed.
- Clownfish and poisonous anemones
97
What is parasitic symbiosis?
Parasite benefits from the host and harms it.
98
What is a parasitoid?
A parasite that causes the death of its host.
99
What is phoresis?
A parasite that is transported by its host.
100
What is intraspecific competition?
Competition between individuals of the same species.
101
What is scramble and contest competition?
Scramble = All individuals decline in fitness
Contests = Some decline, some do not
102
What is interspecific competition?
Competition between individuals of different species. Environmental tolerance of each species is important as well as their niche, which may change due to effects of competition.
103
What is Gause's principle of competition?
Two species with identical niches cannot coexist indefinitely.
104
What are the 6 negative effects of interspecific competition?
1. Consumption of shared resource
2. Pre-emption (first species to arrive wins)
3. Overgrowth (one grows over the other)
4. Chemical interaction (one harms another)
5. Territorial (one deters the other)
6. Encounter (non-territorial meetings)
105
What is Herbivory exploitation?
Predation on autotrophs. Plant is not killed, but has a reduction in fitness. Plant responses:
- Physical
- Chemical (Nitrogen based like cyanide, terpenoids like resin, phenolics like lignin)
106
What is the Lotka-Volterra model?
A model that assumes that the prey consumption rate by a predator is directly proportional to the prey abundance
107
What are the three types of predator prey response?
I: More food = more consumption
II: Predation increases but rate of increase slows due to saturation
III: Similar to II but with a lag due to prey being able to hide to a point.
108
What is a guild?
A group of species that depend on the same resource for survival and reproduction.
109
What is a functional group?
A group of species that perform the same function within the ecological community.
110
What are the three function groups within the guild of Dung Beetles?
Dwellers: go through development within one dung pat
Tunnellers : Bury the dung
Rollers: Remove and hide the dung
111
