FINAL EXAM Flashcards
Directional Selection
An exceptional phenotype that has higher reproduction and survival.
Example of Directional Selection
Finches with larger beaks survived more than those without larger beaks
Disruptive Selection
Average phenotypes have lower reproduction and survival compared to extremes
Permian Period
- Prokaryotes appeared in Paleozoic, later 3 landmasses join to form Pangea
- Mesozoic era. Dinosaurs, birds, flowering plants. Pangea breaks up and drifts north. North America and Africa parted
- End of Mesozoic. Pangea broke up, North America and Eurasia still connected
Cretaceous Period
- Cenozoic. Antarctica and Australia separate
Stabilizing Selection
Extreme phenotypes have lower rates of production and survival. Average phenotype becomes more common
Morphological Species
Based on differences in color, structure, proportions, etc.
Biological Species
A group of actually or potentially interbreeding populations that produce fertile offspring
Allopatric Speciation
Occurs when populations are geographically isolated. Aka geographic speciation
Examples of allopatric speciation
Mountains, rivers, uplifts, etc.
Sympatric Speciation
Production of new species within a population or within dispersal range of a population
Aspects of sympatric speciation (3)
- Often occurs in a patchy environment
- Pre-mating reproductive isolation occurs before population shifts to a new source or habitat
- Induces evolution of a specialization to exploit and unused or novel resource
Aspects of sympatric speciation (3)
- Often occurs in a patchy environment
- Pre-mating reproductive isolation occurs before population shifts to a new source or habitat
- Induces evolution of a specialization to exploit and unused or novel resource
Polyploidy
Abrupt or instantaneous speciation
Types of polyploidy
- 2N + 2N = 4N tetraploid offspring
- 2N + 1 = 3N triploid offspring
- Many agricultural plants do this
Adaptive Radiation
Evolutionary diversification of a species derived from a common ancestor
When does adaptive radiation usually occur?
Aften organisms colonize an island group or new environment
Steps in adaptive radiation
- Physical access to new environment
- Species must be able to exploit new environment
- Enough genetic variation to establish itself under selective pressures of climate in new environment and competition from other species present
Parallel evolution
Adaptive changes in organisms with common evolutionary heritage
Convergent evolution
Development of similar characteristics in unrelated species living in different areas but similar environmental conditions
Population Definition
Group of individuals of the same species living at the same place at the same time
Type I survivorship curve
Juvenile survival is high and most mortality occurs among older individuals
Type II survivorship curve
Individuals die at an equal rate, regardless of age
Type III survivorship curve
Die at higher rate as juveniles and then at much lower rates later in life
Carrying capacity
Theoretical maximum population
Aspects of population growth graph
- Population grows rapidly and then growth stops
2. Growth stops; population stabilizes at carrying capacity, K
Assumptions in logistic population growth graph
- Effect of density on rate of increase is simultaneous
- Population growth is deterministic
- K is constant
To make Logistic Model more realistic
- Build in time lags
- Make r probabilistic
Characteristics of intraspecific competition
- Ultimate effect: decreased contribution of individuals to next generation
- The resource competed for must be in limited supply
- The effect of intraspecific competition on any individual is greater with more
Resource Competition
ie. Scramble, exploitative, etc.
Interference Competition
Contest
K and r selection
Addresses how quickly an organism matures in size at maturity, and how often it reproduces
r selection refers to…
per capita rate of increase. Rate of net production per individual
K selection refers to…
Carrying capacity of logistic growth equation
r selection
unpredictable or ephemeral environment. Density-dependent mortality
strategy of r selection
- Early maturity
- Small size at maturity
- Many, small young
- large reproductive effort
- Shorter life span
- Semelparous
r selection
unpredictable or ephemeral environment. Density-independent mortality
strategy of r selection
- Early maturity
- Small size at maturity
- Many, small young
- large reproductive effort
- Shorter life span
- Semelparous
K selection
predictable or constant environment. Density-dependent mortality.
K selection strategy
- Delayed maturity
- Larger size at maturity
- Fewer, but larger young
- Smaller reproductive effort
- Larger life span
- Iteroparous
Remember, r vs K selection is a…
relative thing
r vs. K selection
- Body size vs generation time: Positive correlation
- r (instantaneous rate of increase) vs weight: negative correlation
- Metabolism vs weight: negative correlation
Chthalamus and balanus experiment
- Upper intertidal zone, removing balanus had little impact on chthalamus survival
- Middle intertidal zone, remocing balanus led to increased suvival of chthalamus
Competitive exclusion principle
Complete competitors cannot exist
Competitive release
Removal of an organism releases another from competition
Character displacement
A change in morphology in response to predators
De Witt Replacement graphs
*Look at what gets affected by mixed cultures
The many definitions of Niche (5)
- Habitat
- Function
- Role
- Address
- N-dimensional hypervalue
Fundamental (potential) niche
The largest ecological niche that an organism or species can occupy in the absence of interspecific competition and predation
Realized niche
The portion of its fundamental niche occupied by a species when competitors or predators are present
Lotka-Volterra Models for interspecific competition
Logistic model
Predation general definition
Consumption of one organism by another; in which prey is alive when first attacked
Predation specific definitions (2)
- Interaction in which an animal (or animals) kill and more or less entirely consume another animal
- Interaction in which one organism kills and more or less entirely consumes another organism
Algal biomass graph
Helicopsyche cause decline in algal biomass, by elevating structures, remove helicopsyche and algal biomass increases
Parasitism
An organism that obtains nutrients from one or few host individuals, but usually doesn’t cause death
Ectoparasite
Happens outside the host. ie. leeches, ticks, certain bats
endoparasite
Happens inside the target host. ie. bilharzia
Model of Disease transmission
schistosomiasis
Examples of diseases
- Bancroftian filarsis
- Oncocerciasis (River blindness)
- Sleeping sickness
- Chagas disease
Mutualism examples
- Cattle egret + deer
- Oxpeckers + hippopotamus
- Ants + Bullhorn acacia
- Bacteria and plants. Rhizosphere population infected and nodule develops
Fertilized soil
tends to put less energy into root development and instead has higher shoot length and biomass due to high nutrients
unfertilized soil
Tend to have more energy allocated toward root development and mycorrhizae
Lichen
fungal-algal mutualism
Lichen
fungal-algal mutualism
Condition
abiotic environmental factor that varies in time and space and to which organisms respond differently
examples of condition
Temperature, water flow rate, pH, humidity
Resource
factor that organism may use up and make less available for others.
ie. nitrogen, light, space
Homeotherms
Approximately constant body temperature. “hot blooded”
poikilotherms
varied body temperatures. “cold blooded”
Endotherms
Heat generated internally
Ectotherms
Heat from environment
Degree-Day Calculations
(degrees) x (number of days) = (degree days)
Ectothermy
Advantages:
- Less energy towards metabolism, can be put toward growth
Disadvantages:
- Amount of livable environments is small
Endothermy
Advantages:
- Have a wider range of environments to live in
Disadvantages:
- Have to allocate more energy towards metabolism than ectotherms, which means less toward growth
El Nino
Sea surface off of coast of South America warms considerably
La Nina
opposite of El Nino, with sea surface off of South America cools
Effects of El Nino
- Less nutrients available for marine species, like anchovies
- Red Kangaroo population declines due to drought in Australia
Effect of El NIno on Great Salt Lake
- Reduced salinity = more corixid predators
- Reduced number of main grazing zooplankton species, Artemia
- In response, phytoplankton mass increases considerably
Origins of lakes
- Temporary ponds - vernal
- Springs -> ponds/streams
- Geothermal pools
- Volcanic
- Tectonic
- Glacial
Seasonal patterns in lakes
- Ice melted by late march and water temperatures are approximately equal from top to bottom
- Late june the top surface gets to ~28 while bottom remains at ~4
- In fall vertical mixing of water column maintains uniform temperatures
- In January, lake is ice covered and top is ~0 while bottom is ~4
Limnetic zone
Open water area where light can penetrate
Profundal zone
Deep water with little to no light
Benthic zone
Bottom-dwelling
Littoral zone
Shallow water area where light penetrates no bottom
Limnetic zone characteristics
- Primary producers: phytoplankton
- Primary consumers: zooplankton
- Epilimnion - source for a lot of biological matter in lake
- Hypolimnion - sink for this much material. Decomposition
Oligotrophic lake characteristics
- Little shore vegetation
- Low concentration of nutrients and plankton
- Sparse fish populations
- Steep sloping shorelines
- Cool temperatures and high oxygen availability
Eutrophic lake characteristics
- much shore vegetation
- high concentration of nutrients and plankton
- dense fish population
- gently sloping shoreline
- warm temperatures and low oxygen availability. favors tolerant fish
- shallow bottom reduces total water volume and increases heating in summer
Dystrophic lakes
- organic matter accumulation > decomposition
- Sphagnum moss underlain by peat
- Acidic
- Bacterial communities suppressed
- slow decomposition
Bog formation in dystrophic
- Precipitation exceeds evaporation
- Poor drainage
- Nutrient-poor soils
- Cool temperatures
Lake succession
- Pond
- Submerged vegetation and sediment accumulation
- Mosses and floating plants. sedges and reeds. sediment accumulation
- Swamp and bog plants. Large sediment accumulation
- Complete colonization by shrubs and trees
Nuisance algal blooms
- imparts green color
- foul tasting water
- Can result in O2 depletion
Typical approach to nuisance algal blooms
herbicides
- temporary effects
- enhances internal cycling
- repeated costs
- not an ecologically sound approach
Alternatives to dealing with nuisance algal blooms
- add zooplankton
- biomanipulation/bioremediation
Goal of lake manipulation experiments
Eradicate an invasive fish, rainbow smelt, to pre-invaded ecological conditions
Gradual Lake Entrainment Lake Converter (GELIs)
- Circulate water so that lake temperature is warm throughout all levels of lake
- By having all warm water, rainbow trout is phased out because they can only survive in cool temperatures
Invasive species
A species that:
- is non native (or alien) to the ecosystem under consideration and
- whose introduction causes or is likely to cause economic or environmental harm or harm to human health
Methods of introduction of invasive species
- Accidental releases
- Transportation
- Range expansion (white perch)
Types of accidental releases
- Aquaculture (brown trout)
- Aquarium trade (oriental weather fish)
Types of transportation (of invasive species)
- Navigation channels (alewife)
- Ballast dumping (zebra mussels)
Consequences of invasive species
- extinction or close to extinction of native species
- organic contaminants can be exposed to humans through fish consumption. (PCB)
- Can be a nuisance in certain areas (midges in Hawaii)
Mitigation methods (of P nubifer)
- Vectobac: spore producing bacterium
- STRIKE pellets (s-methoprene)
Vectobac aspects
- Must be ingested to be lethal
- Have no effect on P. nubifer larval densities or emergence
STRIKE pellet aspects
- juvenile hormone analog
- prevents molting in adult
4 dimensions of lotic systems
- longitudinal
- lateral
- vertical
- time
Longitudinal
- pool: deep, slow-moving
- runs/glides: smooth, fast-moving
- riffles: shallow, turbulent, fast-moving
- rapids: moderately steep, coarse substrates, fast moving
Lateral
- wetted channel - contains water even during low flow
- active channel - actively modified by average stream charges
- riparian zone - transition between aquatic environment and upland terrestrial movement
- floodplain - fluvial surface created by infrequent floods
Vertical
- Water column - water zone to benthic zone
- Benthic zone - the bottom
- Hyporheic zone - transition between surface water flow and groundwater
- Phreatic zone - below the hyporheic zone; contains groundwater
Time (lotic systems)
- Rivers vary across time and space. Resulting in constant changes in size, shape, and content of river
- Forms a mutual interdependence between river and land
Stream order
used to conceptually organize streams in a watershed and provide a basis for describing streams
Low-order streams
1st - 3rd order
Mid-order streams
4th - 6th order
High-order streams
7th - 12th order
85% of streams are…
1st - 3rd order
Watershed
An area of land that intercepts and drains precipitation through a particular river system or group of river systems
Sources of organic matter
- Autochthonous
- Allochthonous
Autochthonous
Originates from the stream
Allochthonous
originates outside the stream
Organic Matter in streams
- Coarse particulate organic matter (CPOM). Greater than 1 mm
- Fine particulate organic matter (FPOM). between .45 um and 1 mm
- Dissolved organic matter (DOM). less than .45 um
River Continuum concept
- model that predicts characteristic changes from upstream (headwaters) to downstream (mouth)
- Incorporates connections between watersheds, floodplains, and streams
- Temperate regions
Human influence of floods
- Increase in impervious surfaces increase the amount of surface runoff which contributes to overland flow
- Forest harvests and agricultural practices affect stream flow
Hydrograph
- plot of discharge vs time
- Show the time it takes from base flow -> maximum discharge -> base flow conditions
Effects of urbanization on storm hydrograph
Runoff peak is higher and lag time between rising limb decreases
General hydrograph patterns
- high in early spring - ice and snow
- Low in summer - High evaporation and uptake by plants
- High in fall - less evaporation and transpiration
- Rainfall patterns - spiky hydrograph
- snowmelt patterns - smooth hydrograph
Hydrograph shape and patterns
- Soil permeability
- Basin size and topology
- forest coverage
- wetland sewage
- impervious surface
Eltonian pyramids
- Pyramid of numbers - can be inverted
- pyramid of biomass - can be inverted
- pyramid of energy - can never be inverted
Primary production
Use of solar energy by plants via photosynthesis to yield plant biomass (biomass of primary producers)
Secondary production
Rate of biomass accumulation by consumers (secondary producers)
Fate of energy in secondary producers
- Amount of 1st degree production available to herbivores -> not ingested
- Ingested by herbivores -> Egestion. Not assimilated >50%
- Assimilated by herbivores -> respiration. respiratory assimilation - energy lost as heat
- Available for growth. Non trophic growth
- Herbivore growth available to predator.
Secondary production estimates: Salmon Creek
- species that do produce well upstream do not produce well downstream and vice versa
Marine Derived Nutrients
- Are derived from freshwater plants, animals, and terrestrial organisms
- Can influence food webs in streams and adjacent terrestrial ecosystems and play a major role in the functioning of these systems , however disturbance is also important
- Salmon can bring substantial MDN into freshwater when they spawn
The different ideologies of ecology
- Preservation
- Conservation
- Land ethic
Rachel Carson’s “Silent Spring” has to do with
DDT
Ecology definition
Relationship between organisms and environment
Darwin’s theory of natural selection
- Variation
- Heritable
- Potential for unlimited growth
- Different individuals have different number of descendants
- Number of descendants - interaction of offspring with environment
Exaption
Characterization shifts 1 use to another
Evolution results from
- Mutations
- Natural selection
- Genetic drift
- Gene flow
Sorghum halepense is resistant to herbicide and glyphosate via
- Mutation
- Translocation of glyphosate within plants
Fundamental niche
Defines physical conditions under which species might live, in absence of interaction with other species
Density
Number of individuals per unit area
Lotika Volterra competition equations based on
Logistic growth equation
Regular distribution
Stingless bees are part of this
Possible explanations of birds coexisting on different heights
- Competition, competitive exclusion, resource partitioning
- Each species competed long ago in past and adapted to different heights
- Not competing and never did
Density Dependent Factors
- Competition
- Disease
- Predation
Interspecific Competition ends to…
Constrict resource utilization curves
Interaction where plants produce chemicals that inhibit growth of competing species is called
Allelopathy
Logistic population growth produces what growth curve
S-shaped growth curve
Fecundity
Number of eggs laid by female
Tribolium beetles are an example of
Identical fundamental niches
Character displacement
Process of evolution toward niche divergence resulting from changes in morphology in face of competition
Prediction
Intelligent guess considering all possible factors
Projection
Takes current rate and says it will continue
Functional response of predators
How predator feeding rates relates to prey density
Optimal foraging theory
Predicts predator will minimize cost/benefit ratio
Conspecific organisms
organisms of same species
Batesian Mimicry
Edible organism should be lower in abundance from inedible
Model of Disease Transmission - Schistosomiasis
Rp =(λ1 Lf)(β1N1Lf)(λ2 Lf)(β2 N2 Lf)
Aspects of model of disease transmission
Rp = basic reproductive rate λ1 = egg production rate of ♀ trematode L = time in infective stage of adult worm f = proportion of ♀♀ surviving to produce eggs β1 = transmission rate from cercaria to humans N1 = human population λ2 = cercariae/snail/time β2 = transmission from miracidia to snail N2 = snail population
Logistic Model:
dN1/dt = r1N1 (K1-N1)/K1
