ECOLOGY

Describe the carbon cycle

1) Carbon dioxide enter the atmosphere through respiration and combustion 2) Carbon dioxide is absorbed by plants to make carbohydrates through photosynthesis 3) Consumers feed on plants passing the carbon compounds along the food chain 4) Most of the carbon consumed is released as carbon dioxide in respiration 5)When organisms die they are eaten by decomposers and the remaining carbon is returned to the atmosphere as carbon dioxide

Describe the carbon cycle:

1) assimilatory and dissimilatory reactions, primarily in photosynthesis and respiration -During photosynthesis, carbon gains electrons and is reduced and chemical energy is gained. (2) Carbon dioxide is continuously exchanged as some molecules are dissolving in the oceans, others are escaping solution to enter the atmosphere. -The total amount of carbon dioxide in the oceans remains constant (3) precipitation of carbonate sediments in the oceans. -when carbon dioxide dissolves in water, it forms carbonic acid, which dissociates into hydrogen, bicarbonate, and carbonate ions. Calcium, when present, equilibrates with the carbonate ions to form calcium carbonate. Calcium carbonate precipitates out of the water column to form sediments. -This process removes carbon from aquatic ecosystems slowly. -Under neutral pH conditions, carbonate and bicarbonate are in chemical equilibrium -Uptake of CO2 for photosynthesis by aquatic algae and plants shifts the equilibrium to the left, resulting in the formation and precipitation of calcium carbonate.

How does foliage height (for example) affect biodiversity of birds?

Foliage height diversity increases -> the opportunities for niche specializations increases -> more bird species can be supported

Density dependent factors function:

bring populations under control and maintain their size close to the carrying capacity set by the availability of resources and condi- tions of the environment.

Shortgrass Prairie Plants (4):

buccalo dactyloides (short curly grass) blue gramma french sage bottlebrush squirrel tail (spindly hairs with seeds feed birds and rodents)

How is the fecundity of females expressed?

in terms of female offspring produced per reproductive season or age interval = bx

______ ______ ______ contribute to reproductive success, they also influence evolutionary fitness.

life history traits

Intraspecific competition function:

like consumer- resource interactions, it regulates population growth in a density-dependent manner

Source of genetic variation =

mutation

What we see as mutualism today may have initially formed as a _____ or _____.

parasitic relationship or reciprocal exploitation -Reciprocal exploitation - each species evolved from reciprocally exploiting each other

The extent the demes interact with each other depends on...

population parameters (they interact through gene flow)

factors affecting the distribution of biomes

temperature and precipitation. Temperature and precipitation interact to determine the conditions and resources available for plant growth → the distributions of the major biomes of the earth follow patterns of temperature and precipitation.

the distributions of the major biomes follow the patterns of _____ and _____

temperature and precipitation. Temperature and precipitation interact to determine the conditions and resources available for plant growth → the distributions of the major biomes of the earth follow patterns of temperature and precipitation.

Factors limiting abundance of species:

temperature, moisture, light

Younger/smaller trees on the border (ecotone) indicates what?

that the tree line is moving into the grass area: Not as much light along ecotone (due to tree shade) puts grass at disadvantage, so trees can grow into the meadow

There are tradeoffs between present reproductive success and future reproductive success such that...

the "sweet spot" is in the middle: the lifetime reproductive success is optimized

Define evolution

the change in allele frequencies over time

Organisms move elements through their cycles within ecosystems when:

whenever they carry out biochemical energy transformations

How do species attain unique gene pools?

reproductive isolating mechanisms

Define sexual selection:

selection by one sex for specific characteristics in individuals of the opposite sex

define adaptive radiation

sequence of rapid evolution that gives rise to many new species, which occurs after mass extinction events or when new areas are colonized

How is character (ecological displacement) related to disruptive selection?

similar to disruptive selection: two species are overlapping in regards to resource exploitation -> resource limited -> species diverge over time (first two graphs) oDisruptive selection manifested in a population when we see multiple species involved as character displacement

Define deme

small/subpopulation

Global patterns in temperature are established by _____ _______. What is the overall pattern?

solar radiation. Warming effect of sun diminishes from equator to the poles Northern Hemisphere receives more solar energy than the Southern Hemisphere during the northern summer and less during the northern winter

Natural selection requires...

variation in a population's gene pool

When allele frequency is 1 or 0, it is _____, meaning

"fixed" = 100% or none of the population has that allele

The Hardy-Weinberg law states that the frequencies of alleles and genotypes will remain constant from generation to generation in a population if that population has

(1) a large (infinite) number of individuals, (2) random mating, (3) no natural selection, (4) no mutation, and (5) no migration between populations

define assimilation efficiency. is it higher for endo- or ectotherms?

(A/I) = (assimilation/ingestion) = how efficient organisms are to use the E they have A/I is high for endotherms (cellular respiration is optimal at any temp) A/I is low for ectotherms

define production efficiency. is it higher for endo- or ectotherms?

(P/A) = (NPP/assimilation) P/A is high for ectotherms because their requirements for metabolism are lower than endotherms

Define trophic cascade:

(Special case of top-down control- any particular higher trophic level affects a lower trophic level) an exaggerated top-down effect in which a higher trophic level affects multiple lower trophic levels (apex predator affects at least two or more trophic levels)

Give an example of character displacement in the field:

(in field) synoptic species Cooper's hawk is sandwiched between Gasser and sharp-chinned hawk leads to more narrow range of cooper's hawk vs. when there is just two species, where both of the species occupy a larger range)

define ecological succession:

(occurs with plants) the order in which organisms move back into an environment after a major disturbance event

Functional Response Curve Types:

*Type I response -Pattern: Not density-dependent and there is no direct response between the predator and prey as a function of the density (predators do not have a controlling effect on the prey populations). -As density of prey increases, the number of prey taken by the predator increases greatly. -As density of prey increases, the proportion of prey taken by the predator increases greatly. *Type II Response -Pattern: Inversely density dependent (predators don't have controlling effect on prey populations) -As density increases, the number of prey consumed increases -As density increases, the proportion of prey consumed decreases *Type III Response -Pattern: Density-dependent up to a point (only opportunity for predators to "control" prey numbers) -As density increases, the number of prey consumed increases -As density increases, the proportion of prey consumed increases (until the prey population increases to a certain point and predators reach a threshold where there are not enough of them to control the prey populations)

Shortgrass Prairie Plant Adaptations to Minimize Water Loss:

- Most of biomass is in root system & small/narrow leaves/flowers minimize water loss through evapotranspiration -Hinge cells parallel to central vein of leaf allow leaf to roll inward to reduce SA and minimize water loss through evapotranspiration -Cutin covers leaves to minimize water loss through evapotranspiration -Fine hair entrap a layer of moisture in the air along the leaf to insulate leaf from heat/winds -Prairie grasses are nocturnal (grow mostly during the night) so they can open their stoma and take in CO2 when the sun isn't out to cause water vapor loss -plants grow parallel to sun rays and leaves curl to protect stomata from water loss -Long vertical roots reach moisture deep below and branching surface roots cover a larger area for water -Buffalo grass use stolons (runner spread over ground surface that produce new plants by developing roots/shoots along prostrate stem joints) -Rhizomes: horizontal stems that can sprout with enough precipitation (buffalo grass) -Grass grows from its base, so when the tip is eaten/broken from trampling from bison, the grass can grow/regenerate

Ecology of Shortgrass Prairie:

-20 winter, 90-100 summer (big temp range) 6-12in precip. (Mostly during monsoons) rainshadow effect (westerlies drop water on hoosier, but winds move west here and warm/dry) most human modified landscape in north america = one of the most endangered natural ecosystem because of loss of area

What is the context of the Island Biogeography Theory (what was observed and what was the question that arose from it)?

-As island area increased, species diversity increased -Islands closer to the mainland supported more species as well -Question: What are the population and community level processes involved with these mechanisms?

Island Biogeography Theory: How does island size affect equilibrium?

-Assuming rates of colonization are constant, the number of species richness at equilibrium is higher at larger islands because smaller islands have a higher extinction rate -On small islands: as species richness increases -> more competition -> decrease in population sizes -> higher extinction rates because there is smaller total area for populations to coexist & fewer niches & more limited resources

Island Biogeography Theory: How does distance to mainland affect equilibrium?

-At equilibrium, the near island holds more species than the more distant island -It is more likely by chance alone that immigration will occur for closer islands to the mainland than further islands = higher rates of immigration -Assuming extinction is constant, more species are present on the near island, because there are higher rates of immigration (by chance alone) -Lines are curved because: high rate of colonization at first as generalized species colonize first -> number of species increases -> only specialized niches are left -> must be colonized by highly specialized species -> rate of colonization slows down

Assumptions/constraints of Island Biogeography Theory:

-Doesn't address differences in organism type (plants vs. animals, mammals vs. birds, etc.) by lumping all species together -different climates of different islands (desert vs. tropical island) -competition is the only factor affecting extinction rates -focuses only on terrestrial organisms -If species are not dying in the matrix (the water) between islands on the mainland (alpine zones, ponds, isolated forests), how does this theory apply (impact extinction and colonization rates)?

How did other studies test the Island Biogeography Theory:

-Experiment: removed insects from islands -Before: nearest islands had the highest species richness -After: the equilibrium number of species after treatment pretty much lined up with the number of species before the treatment -Supports MacArthur and Wilson findings

Fire Adaptations/Ecological Role in Spruce-Fir Forests:

-Fire occurs 100-200 years -Because conditions are mesic and there are short growing periods (drought is rare) -Fuel buildup as a result -> few, high intensity crown fires -Pioneer: Lodgepole Pine -No lower branches = shade intolerant -Has an adaptation for reproduction after crown fires rather than an adaptation for surviving the fire (like Ponderosa in the face of low intensity frequent fires) -Intense heat of fire causes cones to pop open (bracks usually seal seeds inside) -Serrotinous = cones that remain closed (until heat) -Scales flex due to air pressure inside -> seeds fall out -> wind dispersed -We see an 80:20 genotype ratio of serrotinous cones where fires occur (this ratio decreases in fire suppression areas) -Strong pulse of simultaneous regeneration after fire -> even-age stands (vs. the various regeneration of Ponderosa Pine) -With time, lodgepole pine shades itself out -> conditions havor Spruce and Fir -Climax: Spruce and Fir -Presence of lower branches & Young spruce/fir grow in shady areas = shade tolerant

Shortgrass Prairie Animal Adaptations:

-Grasses secrete grains of silica between cells, which abrades teeth of animals -> animals evolved high crowned teeth with hard enamel to resist abrasion -Grazing animals evolved digestive system with large-capacity storage and fermentation chambers preceding the stomach to break down cellulose in grass -Hares/rabbits evolved to eat food twice because their digestive system is not long enough because the fiber they eat is super high in cellulose -> they eat their own pellets to extract the nutrients -Hares with powerful hind legs can run -Pronghorn has long legs with heavy muscles bunched close to body to favor rapid limb movement (since they are not heavy) -Kangaroo rats burrow underground and use tunnels to avoid predators -Cryptic coloration: owls, vesper sparrows, etc. have striped/streaked feathers with brown shades to camouflage -salamanders go dormant underground for years until there is moisture

Describe the two types of competition (type of displacement, effect on species and give an example:

-Interference competition •Overt displacement: One (at least) species is aggressively trying to displace the other in using a limited resource at the same place/time •There is a direct impact on the reproduction and survival as a result of that overt displacement •Ex: Shade tolerant species shading shade intolerant species (Douglas Fir shading Ponderosa Pine) -Exploitation competition •Indirect displacement •Indirect effects that affect on reproduction and survival of a species oResource competition oEx: taproot competition for limited water/nutrients in the soil between plants •Resources = intermediary for interactions between species (species do not directly interact)

Island Biogeography Theory: How does rate of extinction and colonization affect equilibrium?

-Number of species on an island is dependent on rate of colonization and extinction -as number of species on an island increases, colonization decreases -low number of species in the beginning -> more niches available -> rate of colonization is high -> number of species increases -> decrease in available niches -> rate of colonization decreases -as number of species on an island increases, extinction rate increases -set number of niches available: as number of species increases -> sizes of individual populations decrease due to increasing competition -> more likely to see extinctions to happen because competition is so great, and populations are so small -> increased extinction rates

Broad implications of Island Biogeography Theory:

-When setting aside preserves, should we set aside money for large ones or small stepping stone ones? -Influential construct for us in establishing preserves to conserve species

What are the origins of this mutualistic relationship between the yucca and moth?

-Pattern: Ovipositioning (moving around in a flower to get eggs) results in a greater number of seeds and flowers than nectaring (moving around in a flower to get nectar) does - ovipositioning is more effective in fertilizing the flower because it requires more movement than in nectaring -Adaptation= pollination: the effectiveness of moths being pollinators as a result of ovipoisitoning is a behavior that evolved as a derived homology in the ancestry on tegiticulae (a trait the moths evolved as part of this mutualistic relationship with the host flower) -Pattern: As the number of eggs per flower increases, the number of developing seeds increases as well (to a point) - laying more eggs -> moths are moving around the flower more during ovipositioning -> more fertilization of plant -> more seeds -Adaptation= Egg laying in flower: moths that evolved egg laying -> some moths started moving around more in the flower -> more eggs and pollination (natural selection for those moths) -Pattern: Moths have evolved to eat less than 50 percent of the seeds (practicing restraint) because the flower will be aborted (selective abortion = natural selection force) and those genes won't be passed on when the moths die -Adaptation= Host specialization (ancestral preadaptation) - showing restraint in terms of eating relatively fewer seeds (specialized for this particular yucca plant) Summary: most adaptations that are basis for this mutualism appear to have evolved ancestrally (derived: egg laying in flower)

Describe the older Trinidadian Guppy Study (prediction, results, conclusion)

-R = Killifish: prey on inverts, some juvenile guppies - "LP" = low predation -C = Cichilids: prey on larger guppies (adults) - "HP" = high predation •Prediction: If the rate of mortality increases in adults, age at maturity should decrease and the effort invested in reproduction should increase. Predation of Cichilids -> smaller females and males Larger embryo size in bodies of water with killifish Infers: smaller females yield smaller embryos Females yield larger embryos in proportion to their body mass, however Bd. Interval is shorter in cichilid waters because individuals that can produce more frequently are more likely to pass on to the next generation (predation makes adults reproduce more frequently) •Conclusions: below the waterfalls, where the guppies are exposed to intense predation, males mature at a smaller size, and females allot more of their body mass to reproduction, than in populations above the falls. Because the offspring are also subject to high predation rates, females below the waterfalls also produce more, smaller offspring.

Parts of flower:

-Stamen contains anther which has pollen (male gametes) -Colorful flower structure: physically protect gametes and attract pollinators -Stigma: pollen lands and passes down to ovaries -Ovaries: where eggs are fertilized and develop

Define PET:

-The input of energy into a system -the amount of water that could be evaporated from the soil and transpired by plants, given the average temperature and humidity

Why do most predator-prey interactions have built-in time delays?

-because of the time required by both populations to produce offspring. -the influence of prey availability in a particular year may not be felt strongly in a predator population until young born in that year are themselves old enough to reproduce

In the Northern Hemisphere, the number of species in most groups of animals and plants increases:

-increases in species richness from north to south parallel increasing temperatures -increase from east to west in North America, which reflects the influence of geographic heterogeneity. the greater heterogeneity of environments in the West provides suitable conditions for a greater number of species

According to CO life zones, there is a difference in elevational tolerance between trees on North-facing and South-facing slopes. What factors impact this elevational tolerance?

-north-facing slopes in latitudes from about 30 to 55 degrees receive less direct sunlight than south-facing slopes. -as elevation increases, air temperature decreases and air loses energy when it expands into less air pressure -The lack of direct sunlight throughout the day results in north-facing slopes being cooler than south-facing slopes. -During winter months, portions of north-facing slopes may remain shaded throughout the day due to the low angle of the sun -> snow on north-facing slopes to melt slower than on south-facing ones. -In the Northern Hemisphere, soil on south-facing slopes dries out faster and is warmer than soil on north-facing slopes due to longer exposure to sunlight -> vegetation on south-facing slopes in the Northern Hemisphere has less time to take up water because of the drying effect of the sun -warmer south-facing slopes green up sooner in spring, stay greener longer in the fall and tend to be drier than north-facing slopes -Plants that tolerate these hot, dry conditions - which, depending on the region, may be oaks, pines or drought-tolerant shrubs and grasses -grow well on southern slopes in their native range. -A few feet away, a cooler, moister north-facing slope with a gradual incline may be dotted with closed mixed-hardwood or conifer forest and shade-tolerant wildflowers. Trees capture indirect sunlight better than low-growing grasses.

plausible mechanisms that could lead to high tree species richness in a region:

1. Environmental heterogeneity allows species to coexist because they can specialize on different parts of the niche space. 2. Disturbances, such as tree falls, are important sources of environmental heterogeneity in forests. 3. Herbivores and pathogens afflict common species more than they do rare ones, and the resulting rare spe- cies advantage allows many species to coexist. 4. Because tree species are closely matched ecologically, competitive exclusion takes a long time, so species added to a community are likely to remain there.

How to calculate HW equil:

1. Find the observed counts of the genotype in a population 2. Find number of individuals (equal to the Total) 3. Find the number of alleles (=Total x 2) 4. Find p = f(A) = (2(AA) +Aa)/(# of alleles) 5. Find q = f(a) 6. Find f(AA) = p^2 7. Find f(aa) = q^2 8. Find f(Aa) = 2pq 9. Find expected # AA = p^2 x Total 10. Find expected aa and expected Aa 11. Compare to observed counts 12. If expected = approx. observed counts --> HW equil 13. If expected is not equal to observed --> not in HW equil 14. State reasons for why it wouldn't be in HW equil

Factors that function to reduce predator-prey oscillations:

1. Predator inefficiency (or enhanced prey escape or defense strategies) 2. Density-dependent limitation of either the predator or the prey population by factors external to their relationship 3. Alternative food sources for the predator 4. Refuges for the prey at low prey densities 5. Reduced time delays in predator responses to changes in prey abundance

Describe the steps of evolution:

1. Variation among individuals -Variation refers to the differences in a particular trait among individuals in a population, and thus to the variation in that trait contained in the gene pool of the population as a whole 2. Inheritance of that variation -Heritable traits remain stable as they are passed from parent to offspring 3. Differences in survival and reproductive success, or fitness, related to that variation -Fitness refers to the production of descendants over an individual's lifetime. -Heritable traits that promote reproductive success are passed on at a high rate and eventually replace those traits conferring lower fitness → change in the genetic makeup of population = evolution

___ % of usable E is transferred from one trophic level to the next

10%

Gambel's Oak climate conditions:

10-15 inches precipitation (dry) 80-90 degree summers Mild winters Growing season: May-Oct

Alpine-Tundra Conditions:

11,200-14,000 ft High solar radiation Cold winter temps. Strong winds Cool summer temperatures -> trees do not grow Frost-free season: 50 days Variable precipitation: 40 inches (mostly as snow) Wind -> reduces air temp, increases transpiration rates, mechanical abrasion from snow/ice/soil particles, redistributes snow

Factors that determine tree line (and what elevation is it at):

11,500-12,000 ft ~30 days frost free period = short growing season -> restricts above ground growth Wind -> takes away heat/moisture and blows ice particles/snow on trees (kills vascular plants)

Describe the first and second law of thermodynamics:

1st law of thermodynamics: Energy can never be created or destroyed; energy only changes forms (conservation of energy) 2nd law of thermodynamics: As energy changes form (when transferred or transformed), potential energy is decreased and entropy is increased (degradation of usable energy)

Elevational Tolerance Curves:

4,000-6,000ft: grassland 6,000-7,000 ft: Pinon Pine, Juniper, Mtn. Mahogany, Gambel's Oak, Blue Grama 7,000-9,000 ft: ponderosa pine, limber pine, quaking aspen, douglas-fir, white fir, kinnikinnik 9,000-11,500 ft: Spruce-fir, lodgepole pine

Bristlecone Pine traits:

5 needle fascicle Related to Limber Pine White patches on needles (and on pinecones) = resin sacs (resist insects) Large seeds for animal seed dispersal (Clark's Nutcracker) Shade intolerant Poor competitor (doesn't grow in close vicinity to other trees (high up on slopes where there is low nutrients and the least competition) Can grow as low as 7,000 feet but doesn't Branches wide and asymmetrical

Douglas Fir climate conditions:

6,000-9500 feet Confined to sheltered north-facing slopes and cool ravines in lower elevations/All slope aspects in upper montane zone Adapted to cool, mesic conditions

Photosynthesis and Cellular Resp. Equations:

6CO2 + 6H2O ---sun energy----> C6H12O6 + 6O2 6H12O6 ---oxidized--> ATP +CO2 + H2O

How many trophic levels do ecosystems tend to have?

90+% of ecosystems have 4 or fewer trophic levels

define recruitment:

A direct measure of population growth potential: the number of new offspring per individual breeder that join the breeding population in the future

describe examples of keystone species

A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether ex: pinon pine (used by many animals)

define founder event

A single episode of small population size, as might occur during the colonization of an island or a new habi- tat by a few individuals from a large parent population, can reduce genetic variation in the colonizing population

We want to determine age structure of populations because...

Age affects natality rate

Life tables summarize and are a tool for what?

Age-specific mortality, survivorship, and reproductive data for populations of animals/plants = a quantitative tool for describing the effects of ecological factors on population dynamics, and for projecting future population change.

Describe evolutionary tradeoffs in respect to life history tratis:

All of these traits infer there must be tradeoffs - we typically see some of those most prominent evolutionary tradeoffs among traits that are association with reproduction vs. survival

define gene pool

All the alleles of all the genes of every individual in a population

Survivorship curves purpose:

Allow us to depict patterns of survivorship through time Allow us to infer what mechanisms may be underlying the shape of the curve

Altricial vs. precocial

Altricial young - those that are born defenseless Ex: flammulated owl Precocial young - those that are born and can feed themselves/locomote on their own Ex: chickens, turkeys

Reproductive Isolating Mechanisms between sea snakes article:

Are behavioral mechanisms responsible for species isolation between the two sympatric sea snake species and what kind of cues are involved? method: background: lipids (results of convergent evolution for waterproofing) = pheremones = pre-mating species isolating mechanism results: lipids on females differed chemically (colubrina responded the most to colubrina and frontalis respond most to frontalis)

Ecological Factors Affecting Species Richness:

Area, Latitude (perpendicularity of sun's rays), Primary Productivity (NPP), Habitat heterogeneity

Elevation and Fire relationship:

As elevation increases, fire freq. decreases and fire intensity increases More buildup of fuel = more intense More precipitation lingers at higher elevation = small window of dry period for fires to occur = fire frequency lower (Think drought events)

How does latitude affect climate?

As latitude increases, the average annual temperature decreases. oDifferent latitudes experience different angles (of the sun hitting the Earth) Equator = more perpendicular angle

bx =

Average number of offspring (births) per individual during age x

Reznick Article: Guppy

Background/Purpose: -Addresses inconsistencies they saw in mortality patterns of predation level effects on guppies in previous study -So they attempt to see how density plays a role in these patterns -Low predation: higher density -> increased competition for resources (juveniles get less than adults, adults have higher survival) -How does this affect predation and the life history of guppies then? -High predation: lower density -> decreased competition for resources Method: o Change number of guppies in LP environment - tests effect of density on the system (looked at growth, fat content, reproduction, survival) Results: As density increased, individual growth rates decreased Higher density ->more competition -> less food -> less growth As density increased, fat content decreased Higher density -> more competition -> less food -> less fat As density increased, offspring size decreased Conclusion: Density regulation: in areas of high density, mortality increases to return to ambient conditions of lower density ("reset") -Carrying capacity, K, is a function of density dependence

Describe " Coevolution of Pinus ponderosa and Abert's squirrels" (Snyder and Linhart 1998) Study (background, what was tested, findings/significance):

Background: -SCAB are only found where PIPO are -Scirurus aberti feed only one one tree species: Pinus Ponderosa -SCAB feed on vascular cambium of PIPO by chewing through branches with sharp incisors (remove the needles/bark to expose vascular cambium) and then drop the twig to the ground -If tree is favorable, squirrel continues to feed on twigs (targeted selective herbivory) -> PIPO evolved terpenes (selectively using a lot of photosynthetic energy to produce chemical product) to defend against squirrel -> fewer resources directed towards growth, etc. = trade-off between defense and reproductive capabilities -Where SCAB and PIPO overlap -> expect to see high presence of terpenes in the genotypes (Squirrels target PIPO with fewer terpenes -> herbivory by squirrel -> evolutionary trajectory towards genotypes with higher [terpene]) - Where SCAB and PIPO do not overlap -> see evolutionary trajectory towards genotypes with lower [terpene] -The main reason we see different PIPO genotypes is due to the feeding of the SCAB -The main reason we see different SCAB genotypes is due to the influence of the biochemistry of the PIPO Tested: -Sought to ID factors that mediate patterns of selection by different races of SCAB and their PIPO -Is chemical variation in PIPO hosts associated with SCAB feeding patterns? -Is selective herbivory in one SCAB race driven by same specific factors (in the PIPO that they are eating) as those in other SCAB races? = Are these two races feeding on PIPO with the same chemical signal as each other, which may or may not cause the squirrels to feed differently? Findings -Target = trees squirrels are feeding on -Non-target= trees squirrels are not feeding on -Beta-pinene and B-phellandrene = terpenes -Sodium, TNC (carbohydrates), Calcium = nutrients for squirrel -CO xylem: Non-target trees had higher flow rates and terpenes (more fluid going through system -> higher terpene concentrations). The CO squirrels evolved in a trajectory where they built a tolerance to lower concentrations of terpene so that the non-target trees evolved to increase those terpene concentrations. -AZ xylem: Non-target trees had higher beta-pinene. The AZ squirrels have not evolved yet to build a tolerance to terpene like in CO. The AZ trees put the most E into the terpene the squirrels are more sensitive to (pinene). -CO phloem: Target trees had higher sodium and TNC than the non-target trees. CO squirrels select trees with higher [nutrients]. -AZ phloem: Target trees had higher sodium and lower calcium than the non-target trees. AZ squirrels opt for trees with higher [sodium] (like CO squirrels). AZ squirrels do not select for TNC (maybe because non-target and target trees had high TNC to begin with). Significance: -Collectively, CO and AZ trees have different selective pressures from the squirrels. The squirrels in different locations are shaping the evolutionary trajectories of PIPO differently in different locations. -Trophic interactions between squirrels and PIPO mediated by host biochemistry. -SCAB = important agent of natural selection in shaping different PIPO races. -PIPO biochemistry affects ecology/evolution of SCAB populations. (inference) -Such animal/plant interactions may lead to geographically distinct evolutionary outcomes.

Can bell-shaped curves overlap?

Bell-shaped curves can overlap, but not significantly. This allows species to co-exist (in different niches). = niche segregation among ecologically similar species

Bottom-up vs. top-down control of trophic interactions (and examples):

Bottom-up control: the higher trophic levels are primarily affected by the food at lower trophic levels •lower trophic levels control the outcome of higher trophic levels •There is an assumption that trophic interactions are bottom-up dictated. Number of predators controls the density of upper trophic levels (energy flow from the bottom up controls interactions between the trophic levels) -ex: Phytoplankton drive the response of the higher trophic levels -Ex: There is no significant difference between where the rodents were and the rodents were not -> rodents are not having very much influence on the system -> provides support for bottom-up control Top-down control: organisms in the higher trophic levels control the density/diversity of organisms at the lower trophic levels -ex: If predators decrease over time -> the forage fish populations would increase over time -> the zooplankton would decrease over time -> the phytoplankton would increase over time

Spruce-Fir Forest Animal adaptations:

Broad, flexible snowshoe hare feet, dense winter fur on marten feet, stiff feathers on white-tailed ptarmigan = flotation and help to move in snow Good nest insulation, high food consumption, shivering thermogenesis, torpor = chickadees Red fox, porcupine: underfur insulation Gray jays -> loose thick feathering that can be fluff to trap air around body White color: cryptic coloration and minimizes heat exchange with environment

Pinon Jays adaptations:

Cache seeds 10-30 miles from source tree as a flock a couple cm under soil and dig seeds up later (as a group) Use spatial memorization to remember microfeatures context to mark cache

climax vs. pioneer species

Climax - species that follows pioneer species -Continues occupying area in the absence of disturbance event -Ex: douglas fir, white fir -Change environment in a way that is conducive for themselves -Regeneration of climax continues -Shade tolerant, relatively slow growing (K-selected), good competitors Pioneer - first to come in after disturbance event -Ex: ponderosa pine, quaking aspen -Change the environment in a way that's not conducive for their own presence (Ex: shade themselves out) -Prepare way for species with different characteristics (climax) -Turn back succession clock: presence of frequent fires restores conditions to optimal for pioneer species -Shade intolerant, relatively fast growing (R-selected), xeric environment, poor competitors

Describe example of symbiotic mutualism (almost always obligatory):

Coevolution of Yucca and Yucca moth: Yucca characteristics: -rely exclusively on Tegeticula moths for pollination -stigma modified as receptacle to receive pollen -Yucca plant will undergo selective abortion of flower to select for moths laying too many eggs (to the extent that they eat all of the seeds) -Yucca plant has sticky pollen and stigmas for moths to ball up/carry Tegeticula characteristics: -Individuals only visit one Yucca spp -mate within its flowers, lay eggs in ovary and actively pollinate the yucca flowers in which they oviposit - Female yucca moths have ovipositor to penetrate the ovary and deposit eggs -larvae feed on developing seeds (larvae grow nowhere else) - ingested seeds are the major cost of mutualism for the plant -Female yucca moths have specialized mouth parts to carry balls of pollen between yucca flowers

Define coevolution (and describe the two types/give examples of each):

Coevolution: how one species has shaped the evolutionary trajectory of the other in a reciprocal fashion (One species shapes the evolutionary trajectory of the other, which in turn shapes the evolutionary trajectory of the first species in a cyclic nature) General coevolution: Pollination ecology - multiple bees, fly species, hummingbirds pollinate flowers (flowers collectively affect evolutionary trajectory of the animals and pollinators affect evolution of flowers) -Strict coevolution (two species): Abert's Squirrels and Pinus Ponderosa

Types of competition:

Competition between individuals of the same species = intraspecific competition competition between individuals of different species = interspecific competition.

Describe how selection works for oriole nests:

Squirrel nest predation -> selective pressure for orioles evolving to nest in dangling structures off of branches = pendulant nest

Pros of early reproduction:

Decrease predation rates, encroaching senescence at old age, and, for organisms with a life span of a year or less that live in seasonal environments, the end of the reproductive season. increasing the number of off- spring produced today can reduce the number produced tomorrow high mortality rates for adults should tip the balance in favor of reproducing early

2 things that regulate population regulation. Describe their affect on K and mortality, and give examples.

Density-independent Factors (do not affect K, but increase mortality regardless of population size): natural disasters (fires, earthquakes, volcanic eruptions, etc.), can be some diseases, extreme climate factors (precipitation = hurricanes, temperatures = heat waves, etc.) Density-dependent Factors (affects height of K, increase mortality to an extent depending on population size) = can bring the size of a population under control Habitat availability (nest/denning sites), Food resources/Competition for limited resources, Diseases, Predators, Some animals like the flammulated owl, have social behaviors that affect K (relate to a factor causing density-dependence) - like claiming territories

If AA > observed, Aa > observed, aa < observed, why?

Dominant trait has a selective advantage = directional selection (camouflage?); migration/assortative mating because dominant is most attractive/etc.

Ecological systems obey the laws of _____ and exist in ______ states because...

Ecological systems obey the laws of physics Ecological systems exist in dynamic states BECAUSE They continuously exchange matter and energy with surroundings. Living organisms exist out of equilibrium with the physical environment because molecules of life are rare/nonexistent in physical world. Price of maintaining a living system in a dynamic state = energy

What is the relationship between ecology and evolution (give examples):

Ecology influences evolutionary trajectory: -Ex: The cactus interactions with low precipitation in the desert results in cactus being selected for growing longer roots to gather more water Evolutionary trajectories influence ecology: -Ex: Evolution does not favor large bodies in wolves because it comes at cost of agility, so they developed an ecology in which they interact with each other (a new behavior: they hunt together)

define elasticity and what does high elasticity mean?

Elasticity: to what extent a particular factor affects lambda Highly elastic = highly affects lambda in great proportion

Higher biodiveristy is associated with ______. How does this apply to islands?

Everywhere, higher diversity is associated with greater ecological variety Isolated islands exhibit species impoverishment.

Examples of semelparity

Ex: agave store nutrients in roots for years -> hormonal change causes flowering stock to shoot up = reproductive event (using up stored energy) -> plant dies •Ex: mayfly adult lives for a few hours

Ponderosa Pine adaptations/traits:

Fascicles = 3 needles (usually) 1 year cones Long taproot Symbiosis (mutualistic) = mycorrhizal fungi help 95% of trees Facilitate water and nutrients uptake In exchange for carbon and carbohydrates Chemical defense: terpene = Secondary compound Allelopathic = deters herbivory from insects Longer needles - increase amount of captured sunlight Stoma under heavily cutinized needle prevent water loss shade intolerant: A lot of photon energy is required (not efficient with light energy) → requires direct sunlight As they age, they turn orange due to growing thicker bark (a lot of energy): -Toughness from lignified tissues deters herbivores and protects the wound site of trees -Deters fire → thicker bark is more resistant to burning and prevent heat from reaching and burning vascular system inside

Life history strategy and cost of reproduction description example:

Female flammulated owl will put a lot of E into laying a clutch of eggs half her size Male flammulated owl puts a lot of E into feeding the female owl and the young in the nest -In 24 days, young owls become as large as their parents (huge E cost) Life history strategy mimics big birds' strategies with low intrinsic rate of increase, high survival capabilities, and puts lot of E into small family sizes, lots of parental care

How does human interference allowed trees to encroach on the meadow more than ever before?

Fire causes trees (and young trees) to retreat → returns competitive advantage to grasses (no more shade)

How has fire suppression impacted Ponderosa Pine stands?

Fire used to occur frequently from lightning (low intensity fires) -> Killed young ponderosa pine and cleared biomass of floor -> Historically open forest Now: fire suppression → buildup of biomass (grass, needles, etc.) on ground = fuel ladders that allow fire to jump into old Ponderosa limbs and burn them → high intensity crown fires Also overcrowded ponderosa pine stands are susceptible to diseases and insect infestations

Why is fire suppression bad?

Frequent high intensity fires put animals at risk

Ecological purpose of conks:

Fungi on aspen due to vulnerability of aspen's thin bark to fungi spores --> Hollow out the Aspen tree (allow for woodpeckers to make holes easily)

Climate conditions of subalpine zone:

Generous winter snowpack High summer precipitation Long, cold winters Short, cool summers Frost possible during any month Annual precipitation (mostly in snowfall): 28-40 in Snowpack persists into summer Strong winds from the west (esp. near timberline): windthrow of living/dead trees Spruce-Fir Forest: 9,000-11,500 feet

Describe how primary production is measured:

Gross primary production (GPP) - the total E assimilated by autotrophs Respiration (R) - cellular respiration (not available to consumers) Net primary production (NPP) = GPP - R = the E accumulated in plant biomass and available to consumers

Aspen adaptations/climate conditions:

Grow fast and can compete with grasses down below where there is drainage (lots of water and nutrients) 7000-10,000 feet (zones of stress)

how does habitat heterogeneity increase biodiversity?

Habitat heterogeneity = greater physical variation in tropics -> more niches for species to occupy -> increased biodiversity

Clark's Nut Cracker adaptations:

Has long beak that can stab cones before scales open up and eat the seeds before the Pinon jays get to the unripe seeds

Describe example of Nonsymbiotic mutualism (but obligate):

Hypogeous ectomycorrhizae Mycorrhiza produce truffles full of spores -> voles eat truffles underground -> digest truffles -> spores pass through body and are defecated away from original host tree -> spores germinate in the ground -> root down to root hairs and infect new tree host -Note: fungus are important for nutrient absorption by root hairs

λ = 1, λ > 1, λ < 1 means what?

If λ > 1, the population is growing if λ < 1, the population is declining if λ = 1, the population is stable

nitrification (importance, process, important bacteria, summary of reaction):

Importance oNO3: primary source of N for plants oMany plants preferentially use NO3 oCon: NO3 more easily leached -> flushed out after binding to H2O (soil only has NO3 nutrients for short time) •Process Bacteria: oxidation of NH3 to NO2/NO3 •Important bacteria Nitromonas (uses NH3) & Nitrobacter (oxidizes NO2 to NO3) •Summary of reaction NH3 + 1.5O2 -> HNO2 +H2O & NO2 +1.5O2 -> NO3

Define natural selection. Occurs at what level and results in what?

Individuals with traits that are favored achieve higher rates of reproduction and therefore the alleles responsible for those traits increase in the gene pool of the population occurs at the level of the individual and results in higher fitness

Give an example of interference competition with birds:

Interference competition: northern harrier and red tail hawk diets are similar to the point their tolerance curves' tails overlap and thus they harass each other if they get too close to each others' nests

Variable environments favor semel or iteroparity:

Iteroparity: reduce variation in lifetime reproductive success by spreading reproduction over both good and bad years = bet hedging. Semelparity: if a plant can time its reproduction to occur during a very favorable year. (Storing resources and then using them for the big event makes sense)

Juniper vs. Pinon Pine adaptations:

Juniper: Small leaves appressed to stem like scales = outcompete pinon in drought-prone lower elevations Pinon Pine: -2 needle fascicles -Short, waxy needles for water conservation -2 year pine cone seeds are large = big energy expense in a dry climate -Natural selection: more large seeds → more nutritious → attractive to animals to eat long taproots = plumb deep moisture Rapid elongation = roots adjust to changing moisture conditions Branching lateral roots fan out and compete with plants for surface moisture Chemical compounds → antiherbivore action and inhibit competition growth PInon = ethyl caprylate Juniper = terpenes

Juniper vs. Pinon Pine climate conditions:

Juniper: = lower elevation (drier climate) Pinon Pine = higher elevation (cold temperatures) Precipitation: 10-18 inches High evapotranspiration Moderate strong winds Winters: long frost-free periods Summers: hot Greatest seasons of precipitation: southwestern monsoons (Repetitive monsoons cause initial surface water to penetrate deeper) summer precipitation = Cloudbursts = high percentage runoff Soils get dry fast, so roots must work fast

Define carrying capacity

K = the number of individuals the environment can support Because populations below K increase and those above K decrease, K is the eventual steady-state, or equilibrium, size of a population that is growing according to the logistic equation

Type 3 Functional Response Example:

Large outbreak of Mtn. Pine Beetle -> bird species can no longer keep the populations in check

Eltonian (energy) pyramids have what common patterns:

Less Energy, Biomass, and numbers of individuals at higher trophic levels Less biomass at higher levels is due to Loss of E at each trophic level (90% E lost each step) less apex predators

Behavioral costs of reproduction:

Less opportunity to forage for themselves •Compromising thermoregulation -Ex: female flammulated owl loses feathers on belly so she can transfer body heat directly on eggs for thermoregulation = heat loss •Increased exposure to predation -Ex: female perched in cavity entrance/flammulated male owl makes up to 300 trips a night to feed female which makes them vulnerable to predators at night

How to identify: Lodgepole Pine vs. Englemann Spruce vs. Subalpine Fir

Lodgepole Pine: -2 needle fascicle Engelmann Spruce -Terete = diamond-shaped needles = rigidity -Stigma at the base of needles stays behind on trees when needles fall out -Exfoliate - bark pieces slough off tree (thin bark) Subalpine Fir -Flat needles -Smooth bark produced by barm cambium -Light gray color

Describe an example how natural selection worked on Ponderosa Pine:

Lower limbs more apt to die (because they get less sunlight) than in other tree species Natural selection favors shade intolerant trees (with lower branches more apt to die off) because lower branches catch fire

How does fire suppression affect mistletoe and Mtn. Pine beetle?

Mistletoe spread easily in dense stands -Low intensity frequent fires keep stands open to stop spreading Dense trees decrease water access (due to competition) which is a component of phloem that ponderosa pine use to expel beetles -Trees must be strong, and photosynthesize to make sap

How does genetic variation come into play during mitosis and meiosis?

Mitosis is the cellular division of somatic cells from one diploid cell into two genetically identical daughter cells. -the 46 chromosomes make identical replicas of themselves for the offspring sister cell produced. -When homologous chromosomes form pairs during prophase I of meiosis I, crossing-over (the exchange of genetic material between non-sister chromatids of homologous chromosomes) occurs. Meiosis is the process of cell division resulting in 4 genetically unique haploid cells from the single original diploid cell. -This process is used for the sex cells. -The cells produced are not genetically identical because of the recombination and independent assortment that the cells go through. -The number of chromosomes are cut in half during this process. -When cells divide during meiosis, homologous chromosomes are randomly distributed during anaphase I, separating and segregating independently of each other = independent assortment. -In sexual reproduction, two random gametes unite to produce an offspring. This is known as random fertilization.

What is the purpose of the Nitrogen cycle? Why is Nitrogen important?

N2 found in the atmosphere is not usable, but NO3 and NH4 are usable forms. N is a Fundamental component of life: N is important because chromosomal makeup (nitrogenous bases) and Cells -> proteins -> amino acids -> nitrogen

Describe removal of apex predator initiates trophic cascade article

Modified TTRPM to top-down - TTRPM (TDTTRPM) proposes that predators have a moderating effect on grazing pressure by reducing herbivore numbers and altering their behaviour through fear, allowing for positive indirect effects on biomass accumulation. Method: investigate the effects that removal of a large carnivore (dingo)has on herbivore (kangaroo)abundance, vegetation and the soil nutrient pool (dingos common on one side and rare on another) Results: In accordance with the TDTTRPM predictions: kangaroos were more abundant where dingoes were rare kangaroo exclusion had a strong effect on total carbon, total nitrogen and available phosphorus where dingoes were rare, but negligible effect where dingoes were common. Conclusion: a trophic cascade between dingoes, kangaroos and vegetation in a desert ecosystem translates to the soil nutrient pool demonstrates an interaction pathway via which apex predators can influence nutrient dynamics

Seed dispersal and natural selection in Spruce-Fir Forest:

Mountain Chickadees feed on seeds at the top of trees (grow there for optimal wind dispersal) = natural selection (in which cones that grow on top were more reproductively successful)

Why doesn't natural selection result in loss of genetic variation?

Much genetic variation is beyond the reach of natural selection because it has no consequence for the fitness of the individual. Every population is supplied with new genetic variation by mutation and immigration. Movement of individuals between habitats with different environmental conditions can mix genes that have been selected under different conditions and increase genetic variation within the population Natural selection can itself maintain genetic variation when environmental conditions are variable or when individuals that are heterozygous for certain genes have superior fitness.

the curve for dN/dt has its maximum at an intermediate population size of... which is called the_____-

N = K/2, or half the carrying capacity = inflection point -separates the early accelerating phase of population growth from the later decelerating phase.

Describe the evolution of the steps of the Nitrogen Cycle:

N fixation: Evolved in reducing atmosphere Has abundance of H ions used as electron providers (energy rich) Doesn't utilize oxidation (no O2) Nitrogenase gene sequence highly conserved in bacteria, cyanobacteria (hasn't changed over history) Ammonification and nitrification: Arose after N fix because requires oxidizing atmosphere (O2) Denitrification: Probably evolved last (evolved independently multiple times)

Engelmann Spruce and Subalpine Fir Adaptations:

Narrow-spired growth form/downswept branches of spruce and fir minimize snow load and wind resistance Persistent snow loads -> lowest branches remain in contact with soil -> produce adventitious roots through layering -> if layered branch is separated from parent tree -> becomes independent tree through root system Engelmann spruce and subalpine fir carry out peak rates of photosynthesis at optimal temperatures that are lower than typical for other conifers -> extend their photosynthetic system Winter photosynthetic dormancy -> reduces water loss when water replenishment is limited and when winter transpiration must be met through using stored water reserves New shoots "harden off" during summer to maximize their cold tolerance before onset of winter Needle succulence decreases as water content of tissues decreases, allows space for ice crystals to form between cells without causing damage Cuticle covers needle to reduce evaporative loss Compress reproductive stages into less than four months

Define the population parameters and whether they increase or decrease the population. Also which ones are involved with gene flow?

Natality - (the birth rate) increase population Mortality - (the death rate) decrease population Immigration - (individuals coming in) increase population •Gene Flow Emigration - (individuals leaving) decreases population •Gene Flow

Douglas Fir adaptations/traits:

No fascicles/soft needles 1 year cones Shade tolerant (efficient with light)

From subalpine to foothill ecosystems, describe the role of willow (salix) in Riparian ecosystems:

Prevents erosion Provides shade to lower evaporation Feeds deer, beaver, browsers Roots/stems slow flow of water -> nutrients can fall out of suspension and enter the local area Sequesters nutrients and incorporates them into local ecosystem Ecosystems that are oligotrophic (instead of eutrophic) are nutrient-poor without the willow

Describe the slope aspect of Pike National Forest:

North-facing slopes = more snow and trees (cooler temp and lower relative humidity) South-facing slopes = less snow and trees Lower slope = more nutrients → faster growth Top ridge → slow incremental growth (Old trees present because they have never been logged and because of frequent fires)

Describe the woodpecker-aspen interaction:

Not dependent on energy flow (like other interactions) Woodpeckers = primary excavator (for nesting) Flammulated owl = secondary excavator

How is energy lost at each trophic level?

Once ingested, the energy in food follows a variety of paths through the organism: Not all components of food can be assimilated -> defecated/regurgitated = egested energy The portion of this assimilated energy used to meet meta- bolic needs, most of which escapes the organism as heat, makes up respired energy Animals excrete another, usually smaller, portion of assimilated energy in the form of nitrogen-containing organic wastes The new biomass produced by growth and reproduction becomes available to feed organisms at the next trophic level

Where are Hadley cells found?

One Hadley cell forms immediately to the north of the equator and another to the south.

Semelparity (define, taxa involved, why is this strategy a viable reproductive strategy)?

One major reproductive event •Investing all saved energy in a period of time and using it all in the reproductive event •Taxa: several plants and invertebrates (and salmon) o For plants: in an environment with relatively scarce resources (dry habitats), storing energy over a number of poor years with little rainfall -> accumulates so that enough energy can be used to successfully reproduce in one time (during more favorable year) oFor animals: high predation -> producing all at the same time: reduces the likelihood that any one particular individual will be preyed upon (predators can't predict when food will be available -> lower population levels -> not enough numbers to take advantage of huge amount of prey)

Describe the different ecological approaches:

Organism approach - emphasize way in which individual's form, physiology, behavior help it survive in its environment Population approach - variation in numbers of individuals, sex ratio, size of age classes, genetic makeup of population over time Community approach- diversity and relative abundances of different kinds of organisms living together in the same place Ecosystem approach - organisms and their activities in terms of currencies (movement of energy and materials) Biosphere approach - largest scale = movements of water/air and the energy/chemicals they carry over the surface of the entire Earth; natural climate variations

Orientation of sun's rays and tilt of earth's axis -> ?

Orientation of sun's rays and tilt of earth's axis -> seasonality -> differences in plants -> variation in ecosystems

determinants of climate

Orientation of the Earth/Seasonal Shift of Earth's Axis Latitude Hadley Cells Coriolis Effect Proximity to Water Rain Shadows Elevation Slope Aspect

r/k-selection of: Raptors vs. barn owls vs. flammulated owls

Osprey: relatively K-selected (long lifespan, small clutch size, late reproductive age) Barn Owls: relatively r-selected (breed in first year of age, most live to 1-2 years, most only breed once and some don't even get to breed) = live fast and exhaust their life span to try to get reproduction earlier in their life Flammulated Owls: low reproductive rate, delayed age of 1st breeding, high survival rate, long lifespan

How does the number of species change from small to large areas:

Over the smallest areas, beginning with samples that include only a few individuals, the number of species increases with area simply because more individuals are sampled. The slope of this relationship is usually relatively high When areas are large enough so that samples pick up most of the local species, the species-area relationship depends primarily on new habitat types being included in progressively larger areas

"Mistletoes as a keystone resource" Article:

Parasitic relationships may have beneficial properties in being a beneficial keystone resource that increases ecosystem diversity. Mistletoe increases nutrient/understory vegetation and changes host dynamics -> increase colonization/diversity -Results: Where mistletoe was removed: -Declines in specialist frugivores. -No difference in mistletoe foragers -> all bars in Fig 1A overlap. -Decline in mistletoe nesters -> Fig 1B (white dot) -Species richness decreased -> Fig 2A (white dot) -Number of initial residents decreased (sensitivity to drought) -> Fig 2B (white dot) -Discussion: Mistletoe is a keystone species = nutritional resource, provide structures in canopy for bird/mammal nesting, increase litterfall (the litter provides food resources -as they are insect habitats- for birds to feed on) = positive effect of parasitic plants

Define microhabitats/microenvironments

Parts of the environment that can be distinguished by their conditions

Describe the 2 types of mutations:

Point mutation - A substitution of one of the nucleotides in a DNA codon can change the amino acid that it specifies Silent mutation - some nucleotide substitutions leave the amino acid specified by a codon unchanged, and thus have no effect on the phenotype

primary vs. secondary ecological succession:

Primary ecological succession: site has no previous plant community Ex: volcanic explosion Secondary ecological succession: site had previous plant community

Describe the elevational gradient of the Ute Valley:

Ponderosa Pines higher on slopes, Gambles Oak a little farther down, and grasses/yucca at the bottom Abiotic factors: Any precipitation → erosion of materials carried into the meadow (gravity draws water down and carries sediment and nutrients into grassy areas); Amount of topsoil decreases as slope increases Areas of more soil → grasses (with shallow roots); Areas of poorer soil → trees Grass matures 1-2 years Trees mature up to 100 years Grass grows faster → competitive advantage as they shade tree sprouts and take nutrients/water Over time, grasses have a competitive advantage Shrubs grow next because grass has a disadvantage at a higher slope (shallower soil → less water/nutrients = don't match with shallow roots): Gambel's Oak grows where they grow because that's where there is the least competition Trees evolved to grow deeper roots into the poorer soil

What is population distribution?

Population distribution, is the geographic area occupied by a population = geographic range.

Define preadaptations, phylogeny, homology (ancestral and derived):

Preadaptations: adaptation that originally evolved in one context that later evolved to serve another function -phylogeny = hypothesized/proposed ancestry -homology = organisms have a common characteristic because of ancestry -ancestral homology: evolved more distantly -derived homology: evolved most recently with respect to the species in question

Factors affecting NPP:

Precipitation - Positive relationship until a certain threshold is reached Temperature - photosynthesis occurs at temps where water is available and has a positive relationship until a threshold is reached available light and nutrients -direct positive relationship

Describe the closely related oscillations of predator-prey cycles:

Predators eat prey and reduce their numbers -> predators go hungry, and their numbers drop too -> With fewer predators around, the remaining prey survive better, and their populations begin to increase -> With increasing numbers of prey, the predators also begin to increase again

Define sere:

Sere: early successional stage Gives rise to another pioneer species (pioneer species succession) Ex: grasses change conditions for next pioneer species

Age pyramids pros and cons:

Pros: Elicit patterns in births (recruitment) and mortality (deaths) Missing or distortions in age classes can provide insight into environmental influences Cons: Not sufficient information to determine if populations are growing/declining or to determine growth rate

Life tables purpose:

Provide detailed patterns of demography (rates of fecundity and survival) Provides detailed patterns by age class Allows determination of λ: population growth rate

Sources of variation (proximate vs. ultimate):

Proximate - how variation gets distributed among individuals oMeiosis: recombination/crossing over Ultimate -basis of variation in a population oMutations: Substitution, deletion, insertion, inversion = All are random/chance events

type 3 survivorship curve

Quickly declining survivorship in the early age classes before tapering in advanced ages (flattening of survivorship curve) -young individuals are extremely vulnerable to predation and other risk factors, which they escape as they grow larger and mature

r vs. k selected populations

R-selected species (fast): species that have high rates of population increase (high reproductive rates and typically low survival rates) K-selected species (slow): low reproductive rates and high survival rates

R0 = 1 R0 < 1 R0 > 1 Means what?

R0 = 1 = stationary population (individuals replaces herself) R0 < 1 = population decreasing R0 > 1 = population increasing

We expect the values of p and q to remained unchanged through the generations under these conditions:

Random mating No significant amount of mutation and no migration Large population size No selection

Island Biogeography Theory: What are factors affecting equilibrium?

Rate of colonization (infer immigration) Rate of extinction (infer competition) Island Size Distance to Mainland

Forest-tundra ecotone conditions:

Really cold, harsh winds -> limit tree growth and reproduction Sweep snow from ridges and deposit in troughs and depressions Tree islands interrupt transport of snow to develop snow drifts

describe reciprocal transplant experiments:

Reciprocal transplant experiments: involve the switching of individuals between two localities. When the phenotypic values of native and transplanted individuals are the same, we can conclude that the traits of interest are genetically determined— that is, that the trait values reflect the population of origin (genotype) When the trait values reflect where an individual is living (environ- ment) rather than where it comes from (genotype), then the results of the experiment are consistent with phenotypic plasticity. When the individual's response to the environment depends on where it comes from, then the trait values reflect genotype- environment interactions

Fungi in spruce-fir forests

Sarophytic mushrooms -> decomposers -> hyphae permeate rotting logs/soil -> secrete enzymes to break down carbohydrates into sugars -> recycle wood Subterranean mycorrhiza -> sheaths around tree roots -> help tree to absorb water/minerals -> tree feeds fungi sugars from leaves/needles

Dwarf Mistletoes life cycle:

Seeds in capsules Seeds age, dry out and explode to expel seeds in all directions up to 20/30 feet Sticky seeds attach to whatever intercepts them Denser pine stands are more susceptible Must find crevie in bark and access to a little moisture → germination 3-5 years before roots produce surface growth and can reproduce itself

Alpine-Tundra Animal Adaptations:

Small-bodied mammals can utilize moderate microenvironment or beneath ground surface (Under rocks, snow, vegetation) Larger mammals moved towards lower elevations in winter Hibernation -> conserve energy by allowing body temp to drop and reduce metab. Rate -> occurs in underground/subterranean shelter where temp doesn't drop below freezing Birds like horned lark -> behavioral temperature regulation -> bask in sun -> dig shallow roosting holes in the ground during cold nights (exposes minimal body SA) Insects (bumblebees) -> muscular thermogenesis -> heat produced internally -> allows bee to move about when other nectar-feeding animals can't = competitive

Describe a microenvironment that can be taken advantage in Alpine-Tundra:

Snow accumulates between rocks -> supply of moisture during growing season Rock spaces shelter plants from wind and cold

How does slope aspect affect climate?

South-facing slopes in Northern Hemisphere face more direct sun rays -> warms them up more -> warmed to a certain extent -> too dry -> trees can't grow = Sun ray direction impact on a local level

Spatial reconstruction show variable severity fire and rebuttal article:

Spatial reconstruction from GLO survey data -> forests were structurally variable, fires varied in severity (high severity fires were common) = efforts to address fire suppression move forests outside their historical range of variability and threatens biodiversity Rebuttal: data constructed based on false assumption on tree empirical age-size relationships, fire severity classifications (lumped high and mid-severity) ->efforts to address fire suppression are still helpful

How does latitude influence species richness:

Species richness increases from high latitudes toward the equator.

Compare Engelmann Spruce and Subalpine Fir & which tree is found on Pikes Peak?

Spruce and Fir are ecologically similar, but Fir is more mesic than the Spruce because it dominates North-facing stands -Moisture gradient separates the two species -Pikes Peak has more Spruce because it's drier due to it being a lone mountain (more xeric) vs. a mountain range

natural selection (types of selection)

Stabilizing selection: midpoint of bell curve favored over time (individuals with intermediate phenotypes have higher reproductive success than those with extreme phenotypes) Directional selection: one tail of bell curve is selected (the fittest individuals have a more extreme phenotype than the average of the population) Disruptive selection: tails of bell curve are selected (individuals with extreme phenotypes at either end of the population distribution have higher fitness than individuals with intermediate phenotypes)

Alpine-Tundra Plant Adaptations:

Stems/leaves/flowers covered in thick cuticle Low growth forms, small sizes -> more moderate microclimate near ground surface and expose little plant tissue to cold/winds Most biomass/energy infested underground in extensive root/rhizome systems -> provide water/nutrients Coated with hairs to provide insulation, reduce water loss from transpiration, and moderate damage to leaf tissues caused by high UV radiation Round/parabolic flowers with highly reflective petals (starchy granules/oily substance coating petals)= solar collectors by focus heat/light on plant's reproductive organs Initiate photosynthesis at low temperatures & Draw on stored carbohydrates for rapid initial growth in the spring -> cope with short and cold growing season Perennials: enter winter with preformed shoots/buds to initiate growth as soon as environmental conditions become favorable (buds develop within a protective shroud of dead leaves/tissue)

Plant adaptations to herbivores:

Structural adaptations: thorns, spines Allelopathy: secondary plant chemicals (tannins, terpenes, etc.)

______ energy ultimately fuels most biological systems.

Sun energy

How do Hadley Cells affect climate?

Sunlight hits the Earth's surface -> heat is absorbed -> air near ground is warmed -> warm air rises -> air cools -> water precipitates out -> cool air stops rising and is pushed out to the North and South by rising air underneath -> air starts to come down to the ground (has lost most of its moisture) -> As air gets closer to the ground, it starts to warm up again (air's ability to carry water increases as the temperature increases, but relative humidity doesn't increase because there is no new influx of moisture) -> Warm air hits the ground and starts moving (north and south pushed by the warming air coming down towards the Earth's surface) OR ->Air moving towards the equator (picks up water from plants, etc.) gets warmer from influx of the sun's rays and begins to rise again = warm, moist air in tropic rain forest ecosystems = cool dry air in desert climate of subtropical latitudes This process is repeated for Ferrel cells (fueled by Hadley cell) = temperate forests This process is repeated for Polar cells (fueled by Ferrel cells) = dry arctic

type 2 survivorship curve

Survivorship declines at a constant rate through time

Describe the relationship between mycorrhizal fungi and Ponderosa Pine:

Symbiosis (mutualistic) = mycorrhizal fungi help 95% of trees Fungi facilitate water and nutrients uptake in exchange for carbon and carbohydrates from the tree

Describe symbiosis and mutualism

Symbiosis - close physical relationship between organisms Mutualism - when each partner provides something the other lacks

Define symbiosis and the three types of symbiosis:

Symbiosis: long-term interactions Mutualism: both species benefit (+/+) Parasitism: one species benefits, and one species doesn't(+/-) Commensalism: one benefits and the other is neutral

Types of mutualism:

Symbiotic mutualism (almost always obligatory) and Nonsymbiotic mutualism (but obligate)

sympatric vs. synoptic

Sympatric → overlapping distribution (not necessarily interacting with each other) Synoptic → same habitat at the same time

Describe Gambel's Oak adaptations:

Tannins = allelopathy = plant creates chemical compounds = keep animals from eating the tissue & deterrent to germination of other plants (reduces competition) Lignotubers and rhizomatous roots = asexual reproduction hormonal suppression that prevents dormant buds in lignotubers and rhizomatous roots is lifted in response to fire/stress Acorns = sexual reproduction Seeds of acorns = highly nutritious for germinating seeds (which are eaten by mammals) Seeds may be defecated whole → germination leathery/thick leaves prevent water loss due to cutin layer preventing evaporation in dry conditions

How does elevation affect climate?

Temperature decreases with height in troposphere Heated from the ground up = warmer near surface and cooler higher up Air rises into lower pressure areas -> molecules use energy to move apart from each other (air expands) -> air temp. decreases (adiabatic cooling)

Describe what conditions lead to high NPP levels in terrestrial vs. aquatic ecosystems:

Terrestrial: High NPP at warmer temps, abundant rainfall, long seasonal growing period, ample nutrients, direct sunlight, humid air Aquatic: High NPP at more access to terrestrial nutrients, more available light (shallow waters)

define phenotypic plasticity

The capacity of an individual to exhibit different responses to its environment

allopatric speciation definition and process:

The formation of new species in populations that are geographically isolated from one another. occurs when a species separates into two separate groups which are isolated from one another. A physical barrier, such as a mountain range or a waterway, makes it impossible for them to breed with one another. Each species develops differently based on the demands of their unique habitat or the genetic characteristics of the group that are passed on to offspring Original population -> Initial step of speciation = barrier formation -> Evolution of reproductive isolation -> New distinct species after equilibration of new ranges

Why express population growth as exponential equation?

The growth rates of different populations, or of a single population over time, can be compared readily by plotting the logarithm of population size over time

Is variation in a gene pool good?

The more varied a gene pool is, the healthier a population is The more homozygous gene pool -> less variation -> population doomed (unable to adapt to environment changes)

define reaction norm

The observed relationship between the phenotype of an individual and the environment

What makes up a population's age structure?

The proportions of individuals in each age class

Define functional response:

The relationship of an individual predator's rate of food consumption to the density of its prey

Type 1 survivorship curve

There is high survivorship until advanced ages

Solar radiation is a ______ flow of energy which requires ______

This one-way flow of energy (described by laws of thermodynamics) requires there to be a continuous influx of solar energy

Mtn. Pine Beetle and Ponderosa Pine Interactions:

Trees secrete sap to push out female beetles that burrow in Beetles carry blue stain fungus that clog vascular system → kills tree Woodpeckers come to dead trees to look for beetles eating dead trees

White fir adaptations and climate conditions:

True fir (not pine = no fascicles) Light color, smooth bark = young tree -Bark plates grow with age (Mesic) Draining bottoms and north-facing slopes Shade-tolerant: Great competitor in low-light conditions Comes in with time following a fire after other trees regrow (and create shady conditions)

Describe bioaccumulation and biomagnification

Unlike E, solutes accumulate so that the concentration increases with trophic level (E is lost but solutes, and nutrients, are not)

Energy vs. nutrient cycling

Unlike energy, most of which enters ecosystems as light and leaves as heat, nutrients are regenerated and retained largely within the system.

Describe the visible ecotone of Red Rocks:

Visible ecotone: as elevation increases, Gambel's Oak → Pinon Pine (reflects decreasing temperature, relative humidity/moisture)

Where is visible light energy stored?

Visible light energy is stored in covalent bonds Sun E powers the forming of covalent bonds of glucose where E is stored for plants)

How does proximity to water affect climate?

Water heats and cools more slowly than land. Therefore, in the summer, the coastal regions will stay cooler and in winter warmer = A more moderate climate with a smaller temperature range As distance from water increases = a larger temperature range and less precipitation. Currents: Warm water flows from the equator and cold from the poles. Thermohaline circulation causes extensive mixing of the oceans and, more importantly, distributes heat energy from the tropics to higher latitudes.

define adaptation

any phenotypic trait that confers higher reproduction survival

When N =/</> K, dN/dT = ?

When N = K, dN/dT = 0 (population stays constant/no change) When N > K, dN/dT = - (population is decreasing) When N < K, dN/dT = + (population is increasing)

peripatric speciation definition and process and example:

When small groups of individuals break off from the larger group and form a new species same as allopatric speciation, but one of the populations is small -> genetic drift (original population -> new niche entered -> evolution of reproductive isolation in isolated niche -> new distinct species after equilibration of new ranges) Ex: polar bear and Alaskan brown bear = sister species

What happens when species are allopatric (in regards to character displacement)?

Where species are allopatric -> species are more likely using the same resources than in the region of overlap -> divergence (third graph)

Describe Krummholz:

Windward side: -Wind kills needles -Tree island shrinks on windward side Leeward side: -Snow settles behind Krummholz (moisture content and nutrients is highest here) -> good place to grow -Engelmann Spruce root shoots grow on leeward side Krummholz move across slope (tree island mosaic) as windward side dies and leeward side grows -> movement of nutrients across tundra

Within latitudinal belts, how is species richness influenced?

Within latitudinal belts, diversity appears to be correlated with temperature, ecosystem productivity, topographic heterogeneity within a region, and the structural complexity of local habitats.

Ponderosa Pine climate conditions

Xeric: Dry relative humidity 6,000-9,000 ft Winter: up to 30s Summer:60s-70s Growing season: May- Sept Precip: 15 inches and most precipitation occurs during summer monsoons Most snow occurs in early spring

Dwarf Mistletoes traits (and ecological payoff):

Yellow growth on Ponderosa Pine branches (common in Black Forest) Parasitic: -Can't photosynthesize enough to sustain itself -Takes carbon, nutrients, water from tree -Causes sprawling growth form (witch's broom) where it branches from -Lot of photosynthetic tissue in its vicinity (as it penetrates vascular system) -Releases chemical that stimulates plant hormonal growth Ecological payoff: Birds take advantage of witch's brooms for nest protection

Define life history:

a collection of all of an organism's traits that collectively describe the organism's ability to survive and reproduce

what determines fecundity in a female and reproductive success in a male?

a female's ability to gather resources to make eggs determines her fecundity A male's reproductive success usually depends on the number of eggs he can fertilize.

heterozygote advantage example:

anyone who is heterozygous for the sickle-cell hemoglobin allele is protected from both malaria and sickle-cell anemia

Define senescence

a gradual increase in mortality and a decline in fecundity as physiological function deteriorates over time

Define guild:

a group of similar ecological specie

Define trophic levels:

a particular position in the processing of E transfer

Define life history strategy:

a pattern in a life history (the commonalities that show up among different organisms)

5 pre-mating reproductive isolating mechanisms (breeding is not attempted):

a. Geographic isolation— physical/behavioral inability to cross geographic barrier (ex: butterflies in Costa Rica physically separated by mountain range) b. Ecological isolation— different habitat preferences (ex: different warbler species have different foraging zones in a tree) c. Seasonal isolation— breeding in different seasons (ex: brook trout= spawn in fall and rainbow trout = spawn in spring) d. Temporal isolation— mating at different times of day (ex: evening primroses species evolved to open flowers during the day and are pollenated by bees instead of moths) e. Behavioral isolation—sexual preference for unique behaviors (ex: birds evolve different songs)

Post-mating reproductive isolating mechanisms

a. Mechanical isolation— the parts don't fit/incompatible (ex: pollen not compatible with piston in flower) b. Gametic isolation— gametes not physically compatible (biochemical reasons) c. Inviability of hybrids in subsequent generations— offspring that might result are not sexually capable (their morphological development is impacted) d. Sterile hybrids in subsequent generations— (ex: sterile hybrid = mule)

Why are population parameters critical to understand?

absolutely critical to understand as best as possible for a conservation biologist (long-term preservation of species)

Define acclimatization

adaptive phenotypic plasticity ex: Growing thicker fur in winter, producing smaller leaves during the dry season, increasing the number of red cells in the blood at high elevations, producing enzymes with different temperature optima or lipids that remain fluid at different temperatures

4 components of life history:

age at maturity—first reproduction Parity= number of episodes of reproduction Fecundity = number of offspring produced per reproductive episode longevity = how long to live

define allele

alternative form or expression of a gene

impact of environment on population:

although density-dependent factors regulate all populations, variations in the environment also cause populations to fluctuate about their equilibrium sizes

Harvester ant adaptations in shortgrass prairie:

ant hill = mound of pebbles surrounded by bare ground bare ground - queen uses network of tunnels under it to keep larvae - ants create this bare ground so the heat of the ground increases - ants are ectotherms and rely on ground absorbing heat to incubate eggs

How does area affect species richness?

area and species richness have a strong positive correlation -as area increases, habitat heterogeneity increases -expanding area -> expands different ecosystems in area (ecosystem diversity)-> species adapted to different abiotic/biotic conditions -ex: Pikes Peak area ecosystems we visited in the field (different ecosystems due to elevational gradient) -increased area -> increased number of trophic levels: as area increases, higher trophic levels (apex predators) can be supported because they have huge home range requirements

Mechanisms of evolution:

assortative mating, genetic drift, gene flow, natural selection

Define adaptation:

attributes of structure/function that suit an organism to its environmental conditions

Pros of delayed reproduction:

avoid the risks and resource requirements of preparations for reproduction, such as courtship, nest building, and migration to breeding areas Life experience gained with age also reduces the risks associated with breeding. It may also increase foraging efficiency and the number of offspring that parents can provision.

energy is lost at each trophic level because:

because of the work performed by organisms at that level and because of the inefficiency of biological energy transformations

Define biodiversity and species richness:

biodiversity = the variation among organisms and ecological systems at all levels the number of species within an area = species richness

Example of how life history is shaped by natural selection:

birds in higher latitudes lay more eggs at a time because they have longer days in which to gather food during summer when they produce their young

Black-footed ferret and short-grass prairie:

black-footed ferrets =endangered =specialist predation on prairie dogs (highly dependent on prairie dogs) black plague - brought from europe - prairie dogs couldn't evolve to defense against it -> prairie dogs die -> decrease in ferrets loss of habitat due to anthropogenic influence -> decrease in ferret thought to be extinct, 18 found, captured and tried to conserve the population and some released into wild - question of genetic drift causing heterozygote loss so will they have enough genetic variation to survive in the future

Fecundity is directly related to _______ in indeterminate growth species

body size: the larger a female grows, the more eggs she can produce

C3 vs. C4 Plants (define and examples):

c3 = produce 3 carbons during photosynthesis c4 adaptation plants = produce 4 carbons (really drought adapted because they open stomates at night and gas exchange then) all plants photosynthesize through the day and cell resp during night blue gramma = c3 (grows at higher elevations so not as well drought adapted) buffalo grass = c4

Define crypticity (and example)

camouflage = adaptations against predators in ecosystem ex: katydid

Primary production involves fluxes of what?

carbon dioxide, oxygen, minerals, and water

Life history traits include:

clutch size, number of clutches/reproductive season, parental care, division of labor (between parents), viability of eggs, altricial vs. precocial young, type of mating system, etc.

describe examples of coevolution

coevolution - the influence of closely associated species on each other in their evolution. ex: pinon pine and pinon jays

Two ways to construct life tables (disadvantage/advantages)

cohort (or dynamic) life table = follows the fate of a group of individuals born at the same time from birth to the death of the last individual -disadvantage: individuals do not live too long or are not too mobile to track easily and can't disentangle the effects of age from the effects of conditions in particular years static (or time-specific) life table = considers the survival and fecundity of indi- viduals of known age during a single time interval (thus, under the same conditions) -disadvantage: in variable environment, a single static life table could mislead us about the long-term growth of a population (must construct static tables for several time periods)

If AA > observed, Aa < observed, aa> observed, why?

competition (AA found one food source and aa found another) = fitness advantage for both extreme phenotypes Or Assortative mating (AA and aa mate amongst themselves) This is disruptive selection and leads to 2 species

Types of interactions between populations:

competition, predator-prey, disease spread, symbiosis

define ecosystem ecology:

concerned with the cycling of matter and the associated passage of energy through an ecosystem

Two models to approach changes in populations

continuous- time approach = model the way in which populations change instantaneously. -Time flows continuously, and change in a population can occur at every instant Discrete-time approach = to work with time intervals (days or years) that match the natural cycles of activities in populations

Prey adaptations to predators:

crypticity, aposematism

Define proximate factors:

cues, such as day length, by which an organism can assess the state of the environment but which do not directly affect its fitness

Equation for exponential growth rate and ramifications:

dN/dT = rN •dN/dT = instantaneous rate of change of a population •r = intrinsic rate of increase/ innate or natural capacity of increase (natality - mortality) •N = population size •Ramifications: Assume there are no limits in place, emigration and immigration are constant and equal to each other, natality and mortality are constantesd

Equation for logistic growth rate and ramifications:

dN/dT = rN (1-N/K) dT •dN/dT = instantaneous rate of change of a population •r = intrinsic rate of increase/ innate or natural capacity of increase •N = population size •K = carrying capacity •(1 - N/K) = ((K-N)/K) = where the population is with respect to K asymptote •Ramifications: Assume emigration and immigration are constant and equal to each other, natality and mortality are constant, K is constant all the time

How does the Lotka Volterra Model describe the predator populatoin (equation, meaning of equation, and equilibrium):

dP/dt = acVP - dP -[instantaneous rate of change of predator population] = ["birth rate"] - ["death rate"] -When dP/dt = Ø (# of pred. at equil) -> acVP = dP -> V = dP/acP = d/ac -V or R = # of prey (resource) -C = capture efficiency (how many successful captures/attempted captures) -P = # of predators -a = efficiency with which prey are converted to the predator population (efficiency of converting prey into biomass) -d = constant death rate among predators

How does the Lotka Volterra Model describe the prey population (equation, meaning of equation, and equilibrium):

dR/dt = rV - cVP -[instantaneous rate of change of prey population] = [population increase (like exponential growth)] - [number captured] -When dV/dt = Ø (# of prey at equil.) -> rV = cVP -> P = rV/cV = r/c -r = intrinsic rate of increase -V or R = # of prey (resource) -C = capture efficiency (how many successful captures/attempted captures) -P = # of predators

Define equilibrium isocline for predators and prey:

dV/dt = 0 -At any combination of predator and prey numbers that lies in the region below this line, the prey population increases because there are relatively few predators. -In the region above the equilibrium isocline, the prey population decreases because predators remove them faster than they can reproduce. V = d/ac -The predator population can increase only when the abundance of prey lies to the right of the vertical dotted line at V = d/ac, the equilibrium isocline for the predator -To the right of this line, prey are abundant enough to sustain the growth of the predator population. To the left of the isocline, the predator population decreases because prey are scarce

Define: Programmed death

death is a direct consequence of adaptation to maximize reproductive success

determinate vs. indeterminate growth:

determinate: continues to grow only until it reaches sexual maturity •grow throughout their adult lives =indeterminate growth

define sexual dimorphism:

difference in the outward appearance of male and female individuals of the same species

Define character (ecological) displacement:

divergence with respect to the niche space of two particular species

define pleiotropy

effects of a single gene on multiple traits

describe the handicap principle:

elaborate male secondary sexual characteristics act as handicaps. That a male can survive while bearing such a handicap indicates to a female that he has an otherwise superior genotype.

Correlation between PET and species richness?

energy-diversity hypothesis: -a larger amount of energy in an ecosystem can be shared by a larger number of species. -Higher NPP supports larger population sizes, thereby reducing rates of extinction

Structures and functions of organisms are products of _____ in response to

evolutionary change in populations in response to their particular environments

2 models of population growth (describe briefly):

exponential growth rate = j curve = this is the rate at which the population would grow in the absence of any other factors = basic rate of increase capacity of population = inferring relative capacity of increase of population logistic growth rate curve = sigmoid/s-shaped curve = population grows slowly at first, then more rapidly as the number of individuals increases, and finally more slowly again as it approaches the carrying capacity, K (asymptote)

define phenotype

expression of genetic traits

The equations to know for finding HW equil when you have 1 gene, 2 alleles (A and a):

f(A) = p f(a) = q p+q = 1 genotypes: p^2 + 2pq + q^2 = 1 f(AA) + f(Aa) + f(aa) = 1

Reason for type 1 curves in long-lived birds and mammals, but not insects/plants?

high survivorship in younger ages due to high parental care = reduces predation rates

define ultimate factors:

features of the environment, such as food supplies, that bear directly on the fitness of the organism

define sexual selection:

females select attributes in males (that may not contribute to their ability to survive) ex:feathers on a peacock (colorful = easier for predators to see)

food web vs. food chain

food web - multiple sequences of E flow through a system food chain - one sequence of E flow through a system

T =

generation time = the average time from egg to egg, seed to seed, etc "The average time from egg to egg/ seed to seed is ___ years"

define genotype

genetic constitution of an individual

define intrinsic rate of increase of a population

geometric or exponential growth rate (λ or r) assumed by a population with a stable age distribution

how has life history strategy evolved?

have evolved with respect to allocating limited time and resources so as to achieve maximum reproductive success

Why is there higher species richness in the tropics?

high species richness in the tropics results at least in part from the presence of a greater variety of ecological resources

The amount of E that reaches the top depends on:

how efficiently assimilated energy is converted into growth and reproduction— biomass that can be consumed by the next trophic level

The viability of individuals depends on...

how they interact

Reproducing earlier in life than later in life strategic purpose:

if predation is more likely to occur, reproducing earlier means that you are more likely to reproduce before predation occurs

Reproducing later in life than earlier in life strategic purpose:

if you have indeterminate growth, reproducing when you have a larger body size (later in life) -> larger eggs/more eggs from a female

r =

instantaneous rate of change in births and deaths, or per capita rate of increase (r)

Example of evolutionary tradeoff:

kestrel bird When two chicks were subtracted, the survival rates of females and males increased (male is more affected because he expends a lot of energy to hunt prey to feed family) When two chicks were added, the survival rates of females and males decreased. Thus, there is a tradeoff shown empirically between reproduction and adult survival.

Most mechanisms of speciation require:

large areas -Differences in diversity between regions could arise as a consequence of differences in rates of speciation, extinction, or both

What does high connectance mean?

lots of interaction in a food web (ie keystone species) = lots of E flow and organism interactions

Define climate

major factor affecting distribution of plants (autotrophs

Define geometric growth:

many populations grow during a reproductive season (when resources are most abundant), then decline between one reproductive season and the next all counts are separated by the same cycle of birth and death processes. Such an increase (or decrease) over discrete intervals is geometric growth

λ =

measure of the overall rate of population growth "The population is decreasing at a rate of (1 - λ)% annually"

gene flow (definition and importance):

migration of genes from one population to another •Importance: source of genetic variation in populations (increase genetic variation)

How do rain shadows affect climate?

moist air from the west coast reaches a mountain -> air rises/cools and water precipitates out on the west side of mountain -> air falls on east side of mountain and warms up (but is dry - low relative humidity) ex: Death Valley/CO Springs are in a rain shadow Sierra mountain -> death valley -> Rocky mountains (have drier/powdery snow) due to the fact that not much water was collected between the Sierra and Rocky mountains

More productive habitats tend to harbor _____ but_____

more species, but habitats with simple vegetation structure, such as grasslands and marshes, have fewer species than more complex habitats with similar productivity oFor plants, greater structural heterogeneity makes room for more kinds of inhabitants

Types of shifts in niche:

morphological and behavioral

Pinon jays/pinon pine relationship:

mutualistic: pinon jays take up 60+ seeds in mouth and swallow heavy ones Some seeds don't digest and seeds move miles from source tree = seed dispersal

What are the four population paramaters?

natality, mortality, immigration, emigration

evolution can occur through ____ and _____

natural selection and sexual selection

negative density vs. positive density dependence

negative density dependence: Increasing population density usually depresses survival and birth rates positive density dependence: Population growth rates actually increase with increasing population density, especially at low population densities ex: allee effect - individuals are better able to find mates as population density increases.

R0 =

net reproductive rate = the average number of offspring produced by an individual during its lifetime "Throughout its lifetime, the average organism produces ____ seeds/eggs"

Each species has a distinct...

niche

Nitrogen cycle steps:

nitrogen fixation -> ammonification -> nitrification -> dentrification

Mountain Mahogany traits/adaptations:

nitrogen fixer (on root hairs) Awn = feathery part moisture/dry cycles of soil → cracks in the soil freeze/thaw cycle in the day leads to soil expanding and spreading Seed hits the ground first High humidity period (late afternoon/night) → curly feather straightens → awn pushes against organic material on the ground → seed corkscrews into the ground

Every ecosystem has some plant species that evolved to be _______ _______.

nitrogen fixers

assortative mating (definition and importance, also compare positive and negative):

non-random mating •Importance: decreases overall genetic variation in a population Positive assortative mating (mating like with like) reduces the proportion of heterozygotes Mating with unlike partners = negative assortative mating = has the opposite effect of increasing the proportion of heterozygotes

Aspen and Gambel's Oak dependent on asexual reproduction. Why?

o energy doesn't need to be expended in the fusing of genetics o Asexual reproduction is essentially a cloning process, so there isn't the need for outside intervention to reproduce o Because the offspring created through the process of asexual reproduction is essentially a duplicate of the parent, all the positive traits of the species are virtually guaranteed to be passed along o Only one organism is required to establish a colony. osexual reproduction allows smaller organisms to continue to reproduce, especially when there is the possibility of being stationary throughout their entire life cycle. Numerous offspring can be produced and offspring can be produced more often because of the lower energy requirements which are involved in the process

Aspen and Gambel's Oak dependent on sexual reproduction. Why?

o energy doesn't need to be expended in the fusing of genetics o Asexual reproduction is essentially a cloning process, so there isn't the need for outside intervention to reproduce o Because the offspring created through the process of asexual reproduction is essentially a duplicate of the parent, all the positive traits of the species are virtually guaranteed to be passed along o Only one organism is required to establish a colony. osexual reproduction allows smaller organisms to continue to reproduce, especially when there is the possibility of being stationary throughout their entire life cycle. Numerous offspring can be produced and offspring can be produced more often because of the lower energy requirements which are involved in the process

An optimized life history is

one that resolves conflicts between the competing demands of survival and repro- duction to the best advantage of the individual in terms of its fitness

Define natural selection:

only individuals that are well suited to their environments survive and produce offspring (and the favorable traits are inherited)

Ecological system levels:

organism (smallest ecology unit) -> population -> community -> ecosystem -> biosphere

population growth depends on the reproduction and deaths of individuals, which is described on a

per-individual, or per capita, basis

phenotypes are influenced by:

phenotypic traits have a genetic basis, but are also influenced by variations in the environment

Loss of usable forms of E from one trophic level to the next does what?

places a cap on the number of trophic levels in a system (finite levels)

Describe the elevational gradient of Red Rocks:

plains cottonwoods and grass → shrubland → pinon-juniper woodland as elevation increases

Define a self- thinning curve or the -3/2 power law

plant weight and plant density are plotted on logarithmic scales with a slope of approximately -3/2 = relationship between average plant weight and density

Give an example of coevolution in the shortgrass prairie:

plants grow from the bottom (apical meristem is at base of plant) so that they can be eaten but regrow/survive -> buffalo =natural selection force that caused basal apical meristem of plant (coevolved in presence of buffalo)

Smallest entity that can change through time =

population (not individuals)

Describe the theory of density dependence:

populations are self-limiting because resources become scarcer as consumer populations grow. -When resources are limited, mortality increases because individuals are more likely to die from starvation, predation, and disease, and a population may not be able to produce enough offspring to compensate for those deaths

Define community:

populations interacting in the same place at the same time

Shortgrass Prairie keystone species (why is it a keystone species):

prairie dogs: make burrows and many other species (fossorial animals - spend life underground) like rabbits, ferrets, insects, burrowing owls, reptiles, salamanders, etc. nest there = non-energy flow interactions

Define the Lotka-Volterra model:

predicts oscillations in the abundances of predator and prey populations, with predator numbers lagging behind those of their prey

•From an evolutionary point of view, individuals exist to

produce successful progeny— as many as possible

Age pyramids purpose:

qualitatively look at age classes

r = 0, r < 0, and r> 0 means what?

r = 0 = a stable population at a particular point in time. r < 0 = that birth rates are lower than death rates, and the population is declining at a particular point in time. r> 0 = growing population at a particular point in time

Describe r-selectrion vs. K-selection:

r-selected: live fast (early reproduction, semelparity, rapid development, many small offsrping, short lifespan, more variable environment, high mortality, high intrinsic rate of increase, population size in lag/exponential growth part of curve, not strongly favored competitive ability K-selected: live slow (later reproduction, iteroparity, slow development, few large offspring, longer lifespan, more stable environment, low mortality, low intrinsic rate of increase, population size at/near carrying capacity, strongly favored competitive ability)

genetic drift (definition, example, and importance):

random changes in allele frequencies especially in small populations (not due to selection) oEx: brown frogs are in an area that is wiped out by a landslide, leaving only green frogs •Importance: conservation - small populations are a danger to themselves as they lose genetic diversity through genetic drift (decrease genetic variation)

Define niche:

range of conditions an organism can tolerate and the ways of life it pursues (its role in the ecological system)

populations rarely achieve stable age distributions and therefore... Instead...

rarely grow at their intrinsic rates of increase. Instead, the age structure of a population continuously readjusts to changes in environmental con- ditions that alter the schedule of birth and death rates in the life table.

describe sickle-cell anemia:

red blood cells curve into a sickle shape in response to low pH in the blood (acidic conditions)

Define connectance:

reflects on the interactions between one organism and another

Changes in diversity within regions over time reflect the balance of _____ and _____:

speciation and extinction. If new species are produced faster than old ones disappear, diversity should tend to increase until a mass extinction event occurs. Alternatively, diversity might achieve a stable equilibrium at a point at which speciation and extinction exactly balance

sympatric speciation definition and process and example:

speciation of a species in one location with difference niches in it/ exploitation of different niches leads to speciation -Requires assortative mating (original population -> genetic polymorphism -> evolution of reproductive isolation within the population -> new distinct species after equilibration of new ranges) Ex: typically occurs with plants, think of sea snakes article

parapatric speciation definition and process and example:

speciation pattern in which populations speciate while in contact along a common border; a species is spread out over a large geographic area. Although it is possible for any member of the species to mate with another member, individuals only mate with those in their own geographic region (original population -> new niche entered -> evolution of reproductive isolation in adjacent niche -> new distinct species after equilibration of new ranges) Ex: ring species

The ultimate source of diversity is:

speciation: the production of new species by the splitting of evolving lineages

define speciation

splitting of a particular species into additional species

Define ecology

studies patterns of organisms in response to environment

lx =

survivorship = the probability that a newborn individual will be alive at age x.

Define adaptive radiation

the diversification of a group of organisms into forms filling different ecological niches - one species gives rise to multiple species Ex: lemurs radiated into different ecological niches in the absence of competition

Increasing species numbers might encourage______

the extinction rate to rise if competitive exclusion increased with species richness

Species richness is generally paralleled by _______ ________ of the species in a community

the functional diversity or niche diversity,

The equilibrium isocline for the prey is ...

the largest number of predators (P = r/c) that the prey population can sustain

equilibrium theory of island biogeography states:

the number of species on an island balances regional processes governing immigration against local processes governing extinction

The frequency of an allele in a population is:

the number of copies of that allele divided by the total number of copies of that gene in the population.

Define habitat:

the place/physical setting in which an organism lives

define demography:

the study of populations

The rate of primary production (referred to as primary productivity) determines what

the total energy available to the ecosystem.

The abundances and biological activity of organisms at higher trophic levels depend on:

the transfer of energy up the food chain from primary producers

If a species is competing with another species for limited resources, the species that is doing best at resource values where...

there is the least competition will do best (think natural selection)

breeding costs what?

time and resources from other activities and entails risks, investment in offspring generally diminishes the survival of parents. In many cases, rearing offspring drains a parent's resources so much that it produces fewer offspring later

adaptive modifications involve ______ meaning that...

trade-offs: time, energy, or materials devoted to one body structure, physiological function, or behavior cannot be allotted to another

Every individual has _____ copies of each gene

two copies of each gene, one inherited from its mother and one from its father

In reality, most populations have survivorship curves that combine features of type ____ and ____ curves.

type I and type III curves = early vulnerability and later senescence, and the survival rate reaches its highest point in early adulthood

There are tradeoffs that are in direct conflict _____

with each other (lots of energy trying to survive means not much energy can be put into reproducing and vice versa).

Predator adaptions to prey example:

• Great Grey owls hunt for small rodents that crawl under snow insulation and feeding on grass seeds. Rodents make runways under snow cover. Owls strike down into the snow to grab rodents that they can't see. •Has parabolic disc-shaped face, which channels sounds to help them hear in their ear holes. Also have an asymmetrical skull (right ear hole is slightly closer to the sound source, so sound reaches one ear hole before the other -> allows owls to determine distance and pinpoint location of sound source)

How does Orientation of the Earth/Seasonal Shift of Earth's Axis affect climate?

•A given amount of sunlight energy and its effect on Earth depends on the angle in which it hits the Earth's surface oHigher latitudes: light strikes earth's surface at a lower angle and is spread over a greater area oAt the equator: the sun is closer to the perpendicular angle and shines directly down on earth's surface (smaller area and more intensity) •Tilt of Earth's axis is 23.5 degrees -> Variation in Earth's temperatures The tilt of the earth's axis results in a seasonal shift in the latitudinal belt near the equator that receives the greatest amount of sunlight •Seasonality (winter in norther hemisphere due to lower angle and summer in southern hemisphere due to perpendicular angle)

Law of Tolerance (purpose and describe the curve):

•An approach for appreciating how particular environmental factors affect/limit the distribution and abundance of any organism •There is a spot in relation to the environmental factor where the organism does best (optimal zone) •There is a zone of stress on either side where the organism can exist (but not as many) •There is a zone of intolerance is where the organism can't exist on the landscape anymore

What happens to warm air as it rises?

•As warm air rises, it expands. Expansion leads to cooling, which leads to contraction Contraction of molecules -> water vapor molecules can't be held -> water precipitates out

Types of Aposematism (define, how did they evolve, and give example):

•Batesian mimicry - harmless species evolved to adopt the coloration of a toxic species -Harmless butterflies that looked more like monarch butterflies were not eaten by predators as often, so they lived to reproduce and pass on this visual morphology = natural selection Mullerian mimicry - toxic species that have evolved to have a common appearance -One relatively common/distributed toxic species -> predators developed a visual image of -> other species not as widely distributed converged on the common toxic species visual morphology = natural selection -> convergent evolution

Describe the evolutionary effect of character displacement:

•Competitive exclusion principle: no two species can occupy the same space. If they do, one species go extinct or the species evolve •Character displacement -> suggestive of (indirect) competition •When we see niches, we see evidence of competition

Identify the two niche concepts:

•Elton (1927): the place or 'profession' of a species in an ecosystem •Hutchinson (1957): niche consists of many variables (e.g. biotic and abiotic), each of which can be considered in a multi-dimensional space

"Killer Whale Predation..." Estes Article:

•Estes provides evidence for top-down control and trophic cascade •Sea otters are a potential prey of Orca -Orca -> seals and sea lions -> fish -decrease in fish populations (due to overfishing) leads to decrease in seals/sea lion populations -> Orca turn to another food source: sea otters -> decrease in sea otter population •Sea otter -> Sea urchin -> Kelp (primary producers) -decrease in sea otter population led to an increase in sea urchin population and a decrease in kelp •Estes identified pattern in trophic cascades: - Even number of trophic levels: alternating trophic level affect whereby the even trophic levels are affected +/- and the odd trophic levels are -/+ 1. + 2. - 3. + 4. - -Odd number of trophic levels: 3. - 2. + (stronger effect is felt on trophic level 2) 1. -

Fundamental vs Realized Niche:

•Fundamental niche: occupied by a particular species in the absence of competitive interactions (broader curve) •Realized niche: occupied by a particular species in the presence of competitive interactions (narrower curve)

How does heat affect relative humidity? Does warm air or cool air hold more water vapor?

•Heat -> more Energy -> electron orbits farther out -> distance between molecules increases -> capacity to hold moisture increases -> relative humidity increases oWarm air holds more water vapor than cool air

-Primary Literature: "Near extinction of small mammal fauna 25 years after forest fragmentation":

•How rapidly do species disappear from forest fragments (a result of deforestation)- how quickly must humans restore forest connectivity to minimize extinctions? •Surveyed small mammals on forest islands in a reservoir 5 times after isolation to assess species lost •Native small mammal communities disappeared rapidly: -5-7 years after fragmentations, 3 large islands sustained 7-12 species similar to diversity found on mainland -5-7 years after fragmentations, 9 small islands: species richness decline to 1-3 species then after -25-26 years: native small mammals virtually disappeared from all 16 islands -Mean time to extinction of half of resident species: 13.9 +/- 3.9 years -Full relaxation to one species within 40 years, regardless of fragment size -Species diversity decline faster on larger islands than smaller islands (larger islands had shorter extinction half-life) due to faunal collapse -> larger islands had most forest specialists -> species lost -Implication: need to maintain large intact forest blocks to sustain tropical biodiversity

Nitrogen fixation (importance, process, important bacteria, summary of reaction):

•Importance Converts N2 to NH3 (reduction reaction) •Process Bacteria: mutualistic relationship with root nodules •Important bacteria Azobacter (free-living in soil) & Rhizobium (mutualist in root nodules of legumes) •Summary of reaction N2 + 3H2 -> 2NH3 (ATP required)

Ammonification =mineralization (importance, process, important bacteria, summary of reaction):

•Importance NH4: directly absorbed by plant root nodules •Process Bacteria: break down proteins in DOM (plants, animals, fungi) to amino acids (Amino acids then oxidized) •Important bacteria Bascillus and Actinomycetes •Summary of reaction CH2NH2COOH +1.5O2 -> 2CO2 + H2O + NH3 & H2O + NH3 -> NH4

dentrification (importance, process, important bacteria, summary of reaction):

•Importance oReturns NO3 to N2 oif not for this phase, all N becomes fixed oDenitrification and N fixation: mechanisms for returning N from oceans to land •Process Bacteria: facultative anaerobes - prefer O2 environment, but use NO3 as H acceptor (can function in anaerobic and aerobic) •Important bacteria Pseudononas •Summary of reaction C6H12O6 + 4NO3 -> 6CO2 + 6H2O + 2N2

Under what circumstances would effects due to competition be greatest?

•Intraspecific competition (within a species): the more closely aligned the niches, the greater the competition is going to be •Ecologically really similar species that occupy similar niches oEx: two species of hummingbirds competing for the nectar of a flower

Describe the Induced life-history evolution in Trinidadian Guppies study (method, prediction, conclusion):

•Manipulation of predators: moved guppies from killifish water to cichilid waters and vice versa = manipulation to determine whether predation was the factor causing these differences in life histories of the guppies •Prediction: In LP waters, we predict higher age to maturity, proportionally smaller reproductive allotment, larger adult size. o LP (dark line): larger offspring size, lower fecunidity (more eggs but smaller eggs), less reproductive allotment o No clear trend in body size Killifish are more likely to feed on smaller fish in LP and Cichilids are more likely to feed on larger fish in HP (natural selection) More offspring in HP because adults want to reproduce before growing big and being eaten by Cichilids • Conclusions: LP increased embryo size, lower feduncity (more eggs but smaller) • HP smaller adults, higher reproductive allocation, higher fecundity, lower offspring size demonstrated the strength of predation as a selective force in evolution

Competitive Exclusion Principle:

•No two species can simultaneously occupy the same ecological niche •If there were two species occupying the same niche... o...the niche in one of the species would morph in such a way that would reduce competitive interactions (different diet, pH, nesting habits, etc.) o...they would be competing, and one species would eventually go extinct

Define runaway sexual selection:

•Once female choice is established in a population, it exaggerates fitness differences among males and may create runaway sexual selection. Ex: if longer tails in males are what females prefer, then longer tails will evolve (such outlandish traits burden males by making them more conspicuous to predators )

"Coexistence of succulent tree aloes..." article:

•Partitioning the bird pollinator community (through different flower morphology and nectar traits, flowering sequentially, different pollen placement sites, using different bird species) plays a critical role in the co-existence of 5 aloe species (preventing hybridization) -pollinators function as reproductive isolating mechanisms -A. pluridens and A. lineata were highly specialized (longest corolla and lower nectar volume, higher nectar concentration) - requires specialization of the sunbirds species as pollinators -Evidence of segregation - different species of sunbirds keying in on these flowers

What influences biodiveristy in the tropics vs. Northern Hemisphere:

•Precipitation is more influential than energy in the tropics because temperatures are relatively uniform throughout those regions, so differences between those environments are manifested primarily as differences in precipitation. -In contrast, solar radiation and temperature increase dramatically from north to south over the continents of the Northern Hemisphere.

Describe the predator-prey cycle:

•Quadrant 1: As prey population falls below the isocline, it will support fewer predators (decrease in prey -> decrease in predators): inc. P, dec.V •Quad 2: As predators increase above the isocline, the prey decrease (Prey decrease as predators increase): dec. V, dec. P •Quad 3: As the number of predators decrease below the isocline, the number of prey increase again (Prey increase as predators decrease): dec. P, inc. V •Quad 4: As the number of prey increase above the isocline, predators increase as well (increase in prey -> increase in predators): inc. V, inc. P •There is a lag time between predators and prey as they travel from equilibrium to equilibrium (dP/dt = 0 and dR/dt = 0)

Implications of R and K-selection theories:

•R and K selection is a generality that helps us to predict population responses •Enables us to see patterns of survival -> predicted values for conservation efforts. •Can't take this too specifically, some species show R and K-selection traits (are not only one or the other)

Iteroparity (define, taxa involved, why is this strategy a viable reproductive strategy)?

•Repeated reproductive events over a lifetime •Fewer offspring at any one particular time •Taxa: most vertebrates, most perennial plants (including trees) oIn a variable environment, iteroparity reduces variation in lifetime reproductive success by spreading reproduction over both good and bad years oOnly works if the organism has a long enough life span for this to happen

How does the Coriolis Effect affect climate?

•The apparent deflection of global winds (an ocean currents, etc.) due to the rotation of the Earth this is a direct consequence of the rotation of the earth and the conservation of momentum •If not for Earth's rotation, global winds would blow north-south lines (Hadley cells, etc.). Instead they blow diagonally, as they are deflected east/west. Clockwise deflection in Northern Hemisphere -> east Counterclockwise deflection in Southern Hemisphere -> west Polar winds -> Westerlies -> trade winds

Physiological costs of reproduction:

•The energy spent producing gametes/offspring -ex: female spending energy to produce egg or male spending fat reserves hunting to feed female •Lower rates of growth and sustenance (for the adults)

Predator-prey cycles in nature:

•This is a closed system •We typically see these cycles with multiple predators and prey

Describe a global biodiversity pattern

•Tropics (close to the equator) are biological hotspots (more biodiversity) Speculation why: -More precipitation -Direct sunlight -> high levels of NPP

Causes of Type III functional responses:

•a heterogeneous habitat affords a limited number of safe hiding places for prey, and those refuges protect a larger proportion of the prey when there are fewer of them. •when predators encounter prey frequently, they form a search image that helps them to identify and locate suitable prey. At low prey densities, predators encounter prey less often and so do not learn to hunt efficiently •predators may switch to alternative sources of food when particular prey are scarce, reducing pressure on the prey population -> consumption at low prey densities is reduced

K vs. R-selected species:

•the "slow" end of the spectrum = K-species: long life, slow development, delayed maturity, low fecundity, and high parental investment. •the fast end of the spectrum = R-species: short life, fast development, quick maturity, high fecundity, and low parental investment.