PWS 350 Exam 1
d. What are the soil development processes?
Additions and losses to the soil. Translocations= leaching and lateritic movement in the soil. Transformations= transformations of minerals and organic substances and the rearrangement of soil material into structural units.
b. What are the advantages and disadvantages to being a poikilotherm?
Advantage - Low energy. Utilized extreme niches. Often starvation resistant. Disadvantage - Slow growth. Slow movement from predators.
Why is ecological study important?
Allows us to better or to improve Ecosystem services, food production, medicine and disease prevention, preservation of diversity, stewardship. Prevent environmental problems, create policies for managing our eco systems.
What are plant adaptations to the thermal environment (i.e. high temperatures, freezing temperatures)?
Freezing temperatures: desiccation (extreme drying out), glycerol or glycoproteins, dormancy. High temperatures: reflective surfaces, boundary layers (hair or spines), closed stomata, waxy cuticles to prevent water loss
64.What are life histories? What is life history evolution? Define the following terms: maturity, parity, fecundity, and longevity.
Life History distinctive pattern of key life events in a population; shows how organisms invest in growth, reproduction, and survival Life History Evolution: represents the adaptations that constitute the schedule of an organism's life. Maturity: age and size at first reproduction Parity: number of episodes of reproduction (Semelparity, Iteroparity) Fecundity: number of offspring per reproductive episode Longevity: termination of life - senescence
c. Hot environments with moisture stress?
Nocturnal, behavioral (seek shade), burrowing, sweating, panting, gular flutter. With moisture stress: no sweat glands, nasal cavity w/turbinates, highly concentrated urine.
How does the Kangaroo rat deal with terrestrial water limitations?
Its main problem is dehydration. To deal with this it is nocturnal, lives in burrow where temp is lower and humidity is higher, has no sweat glands, has a nasal cavity with turbinates (large surface area for condensation of water), and has highly concentrated urine (3.8 M)
49. a. What are the soil horizons?
Layers of the soil. O=Surface layer of o.m. A=Accumulation of o.m. loss of some clay and soluble matter. E=Maximum leaching formation of granular, platelike or crumble like structures. B=Zone of illuviation. Collection of leached material. C=weathered material. R=unweathered bedrock
h. Describe the water potential differences from soil, root, stem, leaf, atmosphere that would facilitate the movement of water into a root and up the plant to the leaf?
Ψatm < Ψleaf <Ψroot<Ψsoil ((I'm pretty sure))- Water pot. Higher as move up to plant. (More negative/ greater pot. In leaf than in root and than in soil. - soil least negative and potential).
d. What is the field capacity of soil?
Field capacity of soil is -0.1 atm (this occurs when soil is saturated and gravitational water is gone)
a. What is a poikilotherm?
A type of ectotherm. Ectothermic but they don't try to change their inner body (i.e. snakes). Their inner body temperature varies depending on the environment, they don't try to regulate it.
55.What is an adaptation? How does that differ from acclimation?
Adaptation is genetic change over time in response to an environmental change. (irreversible) Adaptation vs Acclimation: adaptation is a change in animal or plant, causing greater overall fitness. Acclimation is a reversible change which happens typically with seasons. Acclimation allows organisms to follow the ups and downs of their environment. (Our bodies can acclimate to different altitudes by altering our hemoglobins ability to bind oxygen but this is not a genetic change.)
74. What are the four types of social organizations among individuals in populations? What is territoriality? What are the types of territories that are defended? Why and how are territories defended?
Altruism: (Individual = Negative/ Other = Positive) - Kin Selection Cooperation: (Individual = Positive/ Other = Positive) - Coevolution of plants and fungi Spitefulness: (Individual = Negative/Other = Negative) - People Selfishness: (Individual = Positive/ Other = Negative) - Leks. Territoriality. Territoriality: The defense of a habitat often for mating grounds or feeding territory. General Purpose Territory: Established during a mating season. Breeding, mating and rearing of the young occurs here (Basically everything). Mating Territory: Feeding not done here Feeding Territory: Feeding territory Nesting territory: only defends area around nest Why defend a territory? Increased probability of survival and improved reproductive success aka increased fitness; We must assume that the ecological benefits of territoriality outweigh cost for territoriality to be practiced; Costs: energy, time, danger. How is territory defended? Each species have their own ways to do it but there are a few general territorial defense methods- 1. Vocally- frogs and birds- sing from conspicuous spot to warn rival the territory is already taken. 2. Visual display is to intimidate rivals 3. Aggressive behavior to attack rival; 4. Scent markers- use of scent and pheromones to mark territory boundaries. Think about your dog and every single tree in the park. 5. Allelopathy-plants put off chemical hormones that keep other plants out of their territory
76. What is altruism? Why is it not common across all organisms? In what groups of insects is it common? What is kin selection theory? How can kin selection explain evolution for altruism? What is the coefficient of relatedness? What are eusocial societies? Haplodiploidy?
Altruism: an action that benefits another individual at the loss of the individual performing the action. Not common because it is not reproductively advantageous, a selfish individual is more likely to survive and reproduce. Limited to Isoptera (termites) and Hymenoptera (ants, bees, wasps) insects True altruism-females lose lives Kin Selection Theory states that an organism is more likely to help another organism which is closely related to it, this way some of their own genes survive, as well as the tendency towards altruism. The closer the relative, the more likely to provide altruism Inclusive fitness= (cost(donor) + benefit(recipient)) *r. r= relatedness coefficient Coefficient of Relatedness: the probability of someone possessing the same genes as yourself Eusocial Societies: entails several adults living together in groups with overlapping generations, cooperation in nest building and brood care, and reproductive dominance by one or a few individuals, including the presence of sterile castes (highest grade of socialistic behavior in the world) Haplodiploidy: a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid.
65.Why can't an organism maximize all aspects of its reproduction? What are the limiting factors?
An organism that could is called a Darwinian Demon and those don't exist. There are simply not enough resources for an organism to max out at every stage of life. Other factors such as growth, climate, predation, time, etc. also play a role. There are limitations, they need to make compromised. competing demands. Limits to time, energy, nutrients. Trade offs: body maintenance, growth, reproduction
What is autecology? Synecology? How does these differ from the other areas of ecological study?
Autecology: INDIVIDUALS individual organisms with their environment. Synecology: COMMUNITIES interactions between organisms and their environments (predator/ prey). "Syn" - together Many other areas of ecology involve different organizational levels of ecology less focused in the individual organism. Other areas include theoretical ecology, evolutionary ecology, population ecology etc. The study of whole plant or animal communities.
Why do we have circulation of heat energy from equatorial regions to the poles? Who was George Hadley and what did he propose regarding thermal circulation? What is a Hadley cell?
Because of the water cycle and its heat transfer force. As solar energy hits the earth's surface the water molecules heat up and evaporate, air mass expands with new energy and density decreases. A bubble of warm air begins to rise. As it rises in the atmosphere, pressure and temperature are reduced causing it to come back down as dry air once. George Hadley proposed that the temperature differential between the poles and the equator would generate two large convection cells, however he did not consider the effect of the coriolis force (effect). This effect deflects winds/currents/etc. clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere Hadley cell = The closed cycle of rising and falling air within the tropics. They are the wind cells immediately north and south of the equator.
54.What is the biome concept? What are ecological tolerances? What are the major terrestrial biomes and how are they distinguished? How did Whittaker define biomes? What environmental factors are used in Whittaker biomes?
Biome concept: Character (plant and animal life) of natural communities is determined by climate, topography, and soil (or parallel influences in aquatic environments). Because of convergence, similar dominant plant forms occur under similar conditions Ecological Tolerances: Several maples in North America have distributions that broadly overlap that of sugar maple: because of different ecological tolerances these other species exhibit distinctive environmental preferences, even when their ranges overlap. The ecological definition of tolerance refers to the niche breadth, or the range of conditions that an organism can withstand. Based on this definition, more tolerant organisms can withstand a broader range of conditions. Temperate seasonal forest-medium precipitation medium temperature Temperate rain forest-high precipitation moderate temperature (CA redwoods) Temperate grassland/desert-no precipitation warm to cold temperatures Woodland/shrubland-bottom of south america low precipitation warm to cold temperatures Subtropical desert-no rain very hot Boreal forest/tiaga-more rain than tundra and a little warmer than tundra Tundra-dry and cold Tropical rainforest- lots of rain very warm weather Tropical seasonal forest/savanna- medium rain very warm weather Whittaker defined biomes as related to annual temperature and precipitation. The biomes fell in a triangular area with corners representing warm-moist, warm-dry, cool-dry He classified them by vegetation, temperature and precipitation.
What are circadian rhythms? Biological clocks?
Circadian rhythms are an innate rhythm of activity and inactivity covering 24 hours. Biological Clocks is a broader term that can mean circadian rhythms or can refer to the body's aging clock. Spans from days, to weeks, months, years
50. How are soils classified? Describe the following soil orders: aridisol, pedocal, mollisol, pedalfer (alfisol), spodosol, and oxisol. Where would you find these soil orders?
Classified by the amount of sand, silt, and clay that makes up the soil. Organic matter and parent material are also very important. Aridisol: Arid Areas. Cemented layer and no Organic Matter (OM) Pedocal: Calcium carbonate layer. Forms in arid/semiarid regions with no OM Mollisol: Good rich soils. Prairies or grasslands. lime in B horizon. Not enough water to heavily leached soils but enough to create o.m. everywhere in middle U.S. Pedalfer (alfisol): High content of Al and Fe. Fertile soil with subsoil clay. close to mollisols. more leached than mollisols and more acidic, clay in B horizon. found in humid climate (Tennessee) Spodosol: Shallow leached horizon and deeper layer of deposition. Humus under sand, dark thin A horizon. Humid areas under coniferous forests, white layer of leached sand in B horizon. Found in Florida and lake states. Oxisol: Rapid nutrient cycling in A horizon. Sandy nutrient poor E horizon. Highly oxidized, formed from leached ultisol. low fertility found in Tropics or subtropics. Hardly ever dry out
What are cold and warm fronts? Why are there tornados in the Midwestern US?
Cold front is a current of cold air coming in off of the ocean forcing itself under warm air(warm air is less dense), pushing it up (often causing precipitation). Warm front is a current of warm air that comes in and pushes itself overtop of cold air. Hot air from the South collides with sinking cool air from the north
b. What are the physical properties of soil?
Color: red= iron, white=gypsum, black/brown=organic matter, purple=manganese. Texture: The amount of sand, silt, and clay. particle size, Gravel >2. Sand 0.05-2. Silt .002-0.05. Clay <.002mm. Depth. Moisture: Clay holds the most. Remember the soil texture triangle. chemical properties
a. What is soil?
Complex Loose terrestrial surface material, has weathered parent material, organic matter, water and dissolved minerals.
e. What is the cation exchange capacity of soil?
Dependent on clay and humus content. Isomorphous substitution is swapping ions without changing shape of crystal. Negative charges prevent leaching of positive charged nutrient cations. The ability of the soil to keep these cations is isomorphous substitution "is the total capacity of a soil to hold exchangeable cations. CEC is an inherent soil characteristic and is difficult to alter significantly. It influences the soil's ability to hold onto essential nutrients and provides a buffer against soil acidification." Higher CEC=higher soil fertility because it holds tightly onto ions Clay has high CEC and Humus has even higher CEC
What is a microclimate? What effects do aspect, soil characteristics, and type of vegetation have on microclimates?
Describes the climate conditions within the area that the organisms inhabit. microclimates affected by vegetation, soil, topography and human alterations. (north vs. south facing slopes = aspect) The slopes facing north are cooler and more moist while the south facing receive more sunlight exposure making them hot and dry with shrubs only growing there. The smaller the vegetation the warmer it is. Vegetation also influences wind flow different wind patterns for pine trees vs. aspen like trees. Differing soil characteristics determine the type of vegetation that can be supported in an area; rocky, nutrient poor soils (high erosion, maybe a steep slope) don't grow much whereas organic matter-rich soils (less erosion, maybe in a riparian area) grow much more and these could affect microclimates
70.What are the sexual patterns of gender allocation that we find in nature? What does it mean to be dioecious, monoecious, hermaphroditic, sequentially hermaphroditic? When would we expect selection to favor a hermaphrodite or dioecy? How are these sexual strategies distributed among living organisms (plants and animals)?
Dioecious, Monoecious, & Hermaphroditic Dioecious - Male and female parts on different individuals. 50% genetic cost. Gonads are expensive . Mating can be dangerous and have a high nutrient cost (i.e. black widows) separate sexes in different individuals Monoecious - Containing both male and female reproductive systems in the same individual. This is specifically for plants. Perfect monoecious is 75% and regular monoecious is 25%. Hermaphroditic - Both male and female functions occur in the same individual (Animal version of monoecious). True hermaphrodites contain both male and female reproductive systems. Sequentially hermaphroditic - They can switch sexes (Ex. ginko tree. Male → Female). Wrassfishes will go from female → male. Hermaphrodite - When resources are scarce and may limit the ability of the organism to collect food, mate (due to nutrition disadvantage), or risk predatorial exposure. more common among sedentary aquatic animals that simply shed their gametes into the water. Dioecy - Actively seek mates and engage in brood care. Reduce sibling competition, reduce parasite or predator tracking efficiency. enhance likelihood of offspring colonizing a new territory, provide repair of adverse gene mutation during synapsis of homologous chromosomes, reduce inbreeding depression permit division of labor among parents Dioecy (Plant - 5% ... Animals - ~100%) Perfect Monoecious (Plants - 75%) Monoecious (Plants - 25% ... Animals [Hermaphroditic] - Marine fishes and nematodes) Sequential Hermaphrodites (More common in plants. Trace in animals) Female → Male (Wrassfishes)
Compare and contrast the following terms: ecology, environmental science, environmentalism, conservation.
Ecology is a science/ study. Environmental science is an applied science, the study of the ecological effect that humans have on the environment. Conservation biology focuses on how to maintain biodiversity. preserving or protecting from human or other major events. Environmentalism is a social and political belief system.they do NOT have to be scientists.
e. How do ectotherms respond to high and low temperatures?
Ectotherms can become increasingly active with a rise in temperature, however if it becomes too hot it must seek shelter. In low temperatures activity in ectotherms decreases. Often they can enter a state of dormancy. It can regulate its body temperature by burrowing or basking in the sun.
52.What has been the pattern of historical climate change? What are the long-term astronomical cycles that help give rise to the observed, cyclical pattern of climate change?
Every 100,000 years theres a warming, a cooling and back up to warming. The last glacial age was the lowest it has been that we have found, and our present time has reached the hottest that it has been on record and of any time we have found. Tilt, Eccentricity (curve of orbit), & procession of the equinoxes
56.What is evolution? What is fitness? What is natural selection? Artificial selection? Define stabilizing, directional, and disruptive selection.
Evolution: Traits of individuals within the populations are continually adjusted to changes in the environment. Any change in a population's gene pool. Change in allelic frequencies in a population over time. Fitness: An organism's ability to reproduce. "production of descendants over an individual's lifetime." Reproduction is most important to Allphin although survivability must play a role in this still. Survival of the sexiest! Yes, well said. Natural Selection: A mechanism of evolution. Frequency of changes in genetic traits in a population via differential survival and reproduction by individuals. The traits of the individuals that leave the most offspring are said to be "selected" and the differential survival and reproduction of individuals having different traits. It does not create new adaptations. It increases and decreases phenotype frequencies. Artificial Selection: The result of conscious decisions made by humans concerning desirable qualities of domesticated or laboratory animals and crops depending on how the environment varies over time and space. Human selection of desirable traits in other organisms. Stabilizing: Occurs when individuals with average phenotypes (generally the most common phenotypes in a population) have higher reproductive success than those with extreme phenotypes. Tends to draw the distribution of phenotypes within a population toward an intermediate, optimum point. Directional: Occurs when the fittest individuals have a more extreme phenotype than the average of the population. Move toward the new optimum. Once that is reached, selection becomes stabilizing. Shift distribution left or right. Disruptive: Individuals with extreme phenotypes at either end of the population distribution might have higher fitness than individuals with intermediate phenotypes. Tends to increase genetic and phenotypic variation within a population. Thought to be relatively uncommon. Shift the distribution left and right.
27.What is facultative endothermy?
Facultative Endothermy: the ability to become endotherm for a specific task such as Pythons brooding eggs, Bees, brooding queen, Bluefin tuna heating visceral mass, billfish heating brain, great white shark heating muscle.
What is the greenhouse effect? How does the burning of fossil fuels and depletion of ozone layer contribute to the greenhouse effect?
Green House Effect: the process by which thermal radiation is absorbed by atmospheric greenhouse gases, and is then re-radiated in all directions. Results in an average elevation of surface temp above what it would be in the absence of gases. Burning fossil fuels adds CO2 to the atmosphere intensifying the greenhouse effect. This can cause rapid global warming. Other pollutants like cholorfluorocarbons react with O3, breaking it apart and depleting the protective ozone layer. With less of an ozone layer, more radiation can get through to the earth's surface and atmosphere. It's good thing that since the Montreal Protocol of 1989 that the ozone hole has been very much patched.
a. What are some of the temperature adaptations of Homeotherms (i.e. gular fluttering, countercurrent heat exchange, retes, torpor, hibernation, diapause etc?)
Gular fluttering - A cooling behavior where birds rapidly flap membranes in their throat to increase evaporation (cormorants, pelicans). Countercurrent heat exchange - Where organisms utilize heat transfer from parallel pipes of flowing fluid (blood) in opposite direction to save energy (can increase or decrease heat loss, ie marine mammals or bird legs). Retes - Bundles used in countercurrent heat exchange; like in penguins and birds' feet Torpor - A voluntary condition of low body temp and low physiological/metabolic activity (usually during the night). Shorter event - ex. one night. Hibernation is a state of winter dormancy involving lowered body temp and metabolic rate (long duration). Diapause - Can be because of cold or some other stress. They delay development. Often during limited resources or a drought. Temporary.
22.What is a halophyte? What are the two problems that saline environments pose? What are plant adaptations to high salinity?
Halophyte: Salt-loving plants. Adapted to severely saline environments. they use salt exclusion, succulence and salt secreting glands. Saline environments have problems with osmotic regulation, and direct toxicity. Adaptations: They may use active transport (energy cost) to excrete the salt out (also called excretion), exclusion, succulence. 1. Osmotic regulation (soil potential is too negative, plant can't get water from it). 2. Direct salt toxicity
59.What is Hardy-Weinberg equilibrium? What are the major assumptions of H-W equilibrium? If deviating from H-W, what might be happening in the population?
Hardy-Weinberg Equilibrium: In a given population where gametes contribute to the next generation randomly, allele frequencies will not change (so no mutations.) Mendelian inheritance preserves genetic variation in a population. p and q are the constant frequencies in a gene pool p2 + 2pq + q2 = 1 The Assumptions: in a situation in which no evolution occurs- no selection (no differential survival or reproduction by genotype,) no differential mutation, no differential migration, no genetic drift, and there is random mating (no differential mating by genotype) Deviation: Nonrandom mating reduces the frequency of heterozygotes and increases homozygotes, which would force the population to deviate from the equilibrium. The probability that an organism will mate with a relative or nonrelative is no longer equal is considered nonrandom mating.
What is heat? What is temperature? Compare and contrast these terms.
Heat is the total amount of kinetic energy, depending on size and how much a substance's molecules can hold. How much energy Q, Joules Temperature measures the intensity of heat based on average kinetic energy. Temp expresses intensity to give up heat. (K, C, F) how fast T Comparison: Heat is the total amount of kinetic energy, depending on size and how much it can hold. Temperature measures the intensity based on average kinetic energy. Temperature expresses intensity to give up heat.
What is homeostasis? Explain a negative feedback loop.
Homeostasis is the tendency toward a relatively stable equilibrium or the maintenance of a relatively constant internal environment within a changing environment. A good example of a negative feedback loop is the thermostat in your home. It is set at a certain temperature, if the temperature rises or falls below the set point it triggers your heater or air conditioner to kick on. It is the same in our bodies if our body needs more calories to keep us warm our body signals to us to consume calories, or triggers metabolism to burn excess fat to gain the calories needed to continue cell processes. In more general terms, a negative feedback loop is sparked when a stimulus disrupts homeostasis and the system tries to regain normality by continuously putting out correctional outputs
What is a homeotherm? What are the advantages and disadvantages to being a homeotherm? What influence does homeothermy have on body size? What is an endotherm?
Homeotherms maintain a constant body temperature, that is not dependant on the temperature of the environment. One of the ways they do this is by increasing or decreasing their metabolism to keep their temperature balanced. Their temperature differs from the external temperatures. Advantage - Can use extremely efficient enzymes that are the most efficient at just a narrow temperature range and live in environments with temperature swings. Can be active without regard for external temperatures and can respond quickly to stimuli despite differences in external and internal temperature. Disadvantage - Enzymes stop working when the animal is outside of the temperature range internally and the animal will die (Proteins denature.) can only be so small in size before the cost of maintaining their metabolism becomes too great (4-5g in size) Homeothermy allows for larger body size. (great white sharks??) Endotherms are homeotherms that create their own heat by bodily processes (burning fat to stay warm, etc.).
53.How have humans modified climate? How do organisms respond to climate change? Will organisms adapt to future climate change?
Humans have increased CO2 in the atmosphere due to fossil fuels and carbon emissions. more cities, more blacktops=warmer climate If a species is vagile, they can move and adapt if climate change is slow enough. Most species have changed along with the climate. However, most ecologists believe that many species will NOT be able to adapt with climate change, due to small population sizes ("stressed" populations), human alterations (loss of suitable habitat and barriers to dispersal), and higher temperatures than what most species have experienced. Humans will have altered the ability for animals to vagile.
62. What is inbreeding? What is inbreeding depression?
Inbreeding: mating among genetic relatives, likely to share identical copies of some of their genes- common ancestors, reduces the proportion of heterozygotes in a populations Inbreeding Depression: When inbreeding lowers the population's ability to survive and reproduce. Reduction in fitness
What is light? Why is light an important part of the physical environment? What is the nature of light? (i.e., spectral quality, intensity, duration, etc.)? What is the fate of light that reaches the earth's surface?
Light is solar radiation and terrestrial radiation. We only see the visible spectra. It is important because it is an energy source for the whole biosphere which plants and animals use, it affects activities, seasonal changes and plant/animal distribution. Regulates temperature. Activates the plants to photosynthesize radiation into energy. Spectral quality:"Photosynthetic Active Radiation - PAR Intensity: Solar constant=1400w/m2 (Outer limits of Earth's atmosphere) Duration: Season to season Directionality: Angle it hits the earth Fate of Light: Some of the light is absorbed, some is transmitted, but the majority of it is reflected back The Greenhouse Effect, Short wavelengths go through the atmosphere, Absorbed or emitted at the surface, IR is absorbed by atmosphere and is converted to heat.
What are macronutrients? What are micronutrients? What are plant adaptations for limitations in nutrient availability?
Macronutrients are chemical compounds that the plant needs in larger quantities, unlike micronutrients which are also chemical compounds but are only needed in smaller quantities. Macro: CHOPKiNS, CaFe, NaCl, MG → Carbon, hydrogen, oxygen, phosphorus, potassium, nitrogen, sulphur, calcium, iron, magnesium. Micro: Cu, Zn, Mo, Co, B, Mn Adaptations include root growth vs shoot growth, leaf longevity, nutrient translocation and tolerance.
68. Who was David Lack? What role did he play in life-history research? What was his major research finding?
Made life history an actual science. First to equate fitness to reproductive success. Hypothesized that limited food supply limits the amount of offspring a parent can rear. 1) That clutch size indicated the number of potentially healthy offspring 2) Competition and long nights in the tropics reduced the clutch size The important points of his research were... He equated fitness to reproductive success and thus evolutionary competitiveness Showed that life history events are related to specific environments Made testable hypotheses - Ex. Food supply may limit the # of offspring a parent can rear
What is a maritime climate? What are the maritime effects on regional climate?
Maritime Climate: Climate that has a narrow range of temperature change. Effects on Regional Climate: Warm but not hot summers, cool but not cold winters. (Maritime climate helps avoid extremes for regional climate; water acts as a buffer)
72.What are mating systems? What is monogamy? What is polygamy? Polygyny? Polyandry? What is the polygyny threshold model? What is promiscuity? What is a lek? What are some of the hypotheses used to explain leks?
Mating Systems: Monogamy, polygamy, polygyny, polyandry Monogamy: One male with one female. Polygamy: you just might be a mormon, if the word 'polygamy' means somethin to ya. Polygyny: one male with several females. Polyandry: one female with several males. Typical of poor habitats. Maybe because the female can produce as many offspring as possible and let the male take care of it while she finds another mate, to try and get as many survivors as possible? Polygyny Threshold Model:When it is most cost efficient to be a second female to a male then to be a first female to a not so good male. Females may choose to enter a polygynous relationship if superior resources on male territory mean that she would do better than being a monogamous female in an inferior territory. Promiscuity: Males and females mate at several different times with different mates, to optimize fitness. Lek: A promiscuous mating ground.A community where males gather so that the females need to come to them. Theories for Leks: There is decreased predation, increased efficiency of attracting mates. Make use of limited display sites. Take advantage of female preference for areas with clumped males. A community where males gather so that the females need to come to them.
c. What are the types of weathering?
Mechanical- Glaciers, freeze/thaw cycles, waterways etc. Chemical- Oxidation/reduction, dissolving in water, Hydrolysis, Carbonation
What constitutes the physical environment?
Most importantly: light, temperature, water/moisture, nutrients.
How does light affect photosynthesis?
Most plants are green because they reflect green light. They utilize chlorophyll and carotenoids. What they absorb is the frequency the excites electrons in the photosystems. Carotenoids absorb green and reflect back orange (PSII 680nm). Chlorophyll absorbs red/violet and reflects back green. (PSI 700)
58.How does genetic variation arise in natural populations? What are the main types of mutations? What are gene interactions? Epistasis? Sexual recombination? Gene flow? Why is genetic variation important in natural populations? What is heterozygote advantage?
Mutations, reproduction, genetic drift and flow Point mutations- Transitions, frameshifts, transversions, etc. Involve changes in nucleotide bases at single locations Chromosomal mutations- Involves rearranging of genes. Inversions, translocations, duplication, etc. Gene interactions- Dominance, epistasis, modifier genes, gene linkage, etc. Epistasis: interaction of nonallelic genes such that one gene affects the expression of another at a different locus either positive or negative, combinations of genes can elicit even stronger selection Sexual Recombination- Produces new genetic variation rapidly where mutation does so very slowly (multiplies the level of variation) Gene Flow:exchange of genes between populations from migration, random Genetic Variation: Increased genetic variation provides an advantage in adapting to changing environments. It is also needed for natural selection to bring about evolutionary change. It increases fitness. Heterozygote Advantage occurs when heterozygotes have a higher fitness than do both homozygotes. Natural selection will tend to maintain two or more alleles at that locus (thus the recessive and the dominant) so it is good to have BOTH genes and both give good traits. Heterozygote advantage results in more genetic variation in the population. Example: the sickle-cell allele causes mutations in hemoglobin but also confers malaria resistance
63.How does natural selection affect allele frequencies in populations? What is fitness? What is s?
Natural Selection screens the heritable variation in each generation, increasing the frequencies of some variations and decreasing the frequencies of others over the generations. Fitness is the relative ability for reproductive success under selection pressure. Fitness is often described by the selection coefficient, s. s is a measure of the degree to which selection acts against a particular genotype (compares the fitness of a genotype to another favored genotype, if s=1 then it is highly unfavored) ex: w=1-s. If s=1, w=o meaning that genotype is not fit.
What controls regional climates? What are topographical effects? What are the wet and dry adiabatic rates? Could these be used to determine the change in temperature with rise in elevation? What is Hopkin's law?
Ocean currents, atmospheric movements , Continental location, Near to large bodies of water, Topographic Features. The position of continental land masses (more rain in the southern hemisphere due to the land to water ratio) and slopes facing North or South Topographical Effects: Rain Shadows (mountains), canyon winds, water bodies, valleys Dry rate: 1 Degree C for every 100 Meters Wet Rate: 0.6 Degrees C for every 100 Meters. Yes Hopkin's Law: Phenological Flowering dates are retarded 1 day for each 100 Meters of altitude and 1 day for each 15' latitude.
What are the levels of organization in ecology (communities, populations, etc)?
Organisms- Populations- Communities- Ecosystems- Biosphere
What is PAR? What are plant adaptations to variation in PAR? How does the periodicity of light affect plant processes? What are short-day vs. long-day plants?
PAR is Photosynthetically Active Radiation. Some plant adaptations to variation in PAR include; 1) Shade Tolerant plants: develop thinner, broader leaves (increased surface area), reduced photosynthetic rate per leaf area, low respiration and metabolic rates. 2) Shade intolerant plants: develop leaf reflectance (barriers to UV penetration), diffuse direct sunlight with spines and hairs The periodicity of light affects plant processes by affecting the phenology and altering flowering and non-flowering dependent on the hours of daylight received. Short day plants only form blossoms when the day length is less than 12 hours, and long day plants only flower when they receive more than 12 hours of sun (short day flower < 12 hours < long day flower) (related to photoperiodism: the response of an organism [plant] to light length)
How are ecological studies performed? How do ecologists deal with ecological complexity in their studies? What are microcosm experiments? Mathematical models?
Performed by implementing the scientific method, Based on experimental hypothesis testing. OHPE - Observation, hypothesis, prediction, experimentation. Ecologists deal with complexities by using Mathematical models and Microcosm Experiments. Mathematical Models: A model is an abstract representation of the real system, with an explicit set of assumptions. They require validation. Uses mathematical concepts and language. Microcosm Experiments: are experiments in artificial, simplified ecosystems that are used to simulate and predict the behaviour of natural ecosystems under controlled conditions.
57.What is phenotypic plasticity? What is a reaction norm? What is genotype-environment interaction? What is a reciprocal transplant experiment and why are they performed? What types of studies are done to determine whether or not differences among populations/groups are plastic responses to the environment or genetic differences?
Phenotypic Plasticity: Can change your phenotype in response to environment. Higher phenotypic plasticity allows for greater ability to acclimate. The degree of sensitivity to environmental changes. Reaction Norm: The quantitative relationship between phenotypic variables and environmental variables. (Ex. 1 species of moth grows larger during high temps than another). Evolution can alter the reaction norm. Genotype-Environment Interaction: Different genotypes in the same species having variable responses to the environment (Ex. directional selection). Reciprocal Transplant:Transplant two different populations of organisms and observe/quantify their relative growth patterns. This could indicate evolutionary processes especially if there is variation in the reaction norms. Genetic - If they don't change their phenotype. Plastic - If they can change their phenotype to adjust to the environmental factors. Transplantation Studies
What are plant responses and adaptations to short and long-term variations in water stress? What are C4 and CAM photosynthesis? In what ways do these alternate photosynthetic pathways constitute adaptations?
Plants can adapt by using reflective surfaces, hairy leaves, small leaves, position, closed stomata, waxy surfaces etc. They can have longer roots, less on top, increased water storage cells. They can grow in microenvironments where osmotic stress is lower etc. C3 - grow in normal areas when water loss isn't a problem, stomata can stay open. Calvin cycle in mesophyll, not efficient at high temperatures C4 -grow in tropical regions (hot and moist). The dark reactions go into the mesophyllic cell. PEP-carboxylase. Situational difference. Efficient way of trapping Co2 with their 4-carbon molecule that does not react with O2 so their stomata only has to be open for a short period. Does Calvin Cycle in the bundle sheath cells, doesn't do respiration CAM - Temporal plants, found when its hot/dry open stomata at night, and fix CO2 with PEP at night; do Calvin Cycle during the day time They open their stomates at night. Usually in desert systems, hot and dry climate evapotranspiration. Adaptations of PEP carbox. Allows us to do CAM
a. How do plants uptake water?
Plants uptake water by INcreasing the negative potential in their roots to be more negative than the soil moisture potential (water flows from high to low pressure, so the plants need to have a lower pressure than the water in the soil to move water up and through them) Plants increase negative potential in their roots by increasing the amount of solutes.
d. How do plants uptake water from the soil?
Plants uptake water by passive absorption which is root extension or active absorption (example: Cati) Which requires energy pumps water. Capilliary action. Negative water potential water is polar and so it's negative end attracts to the roots where ions are waiting. Negative water potential, water moves from high to low pressure (?)
What are plant adaptations to flooding or standing water?
Pneumatophores - Root knees that protrude above water and carry oxygen to root. Aerenchyma - Large air-filled intercellular spaces that allow some gas exchange between submerged and better aerated roots.
51.Describe podsolization and laterization.
Podsolization - In acidic soils in cool, moist regions of the temperate, clay particles break down in the E horizons and their soluble ions are transported downward and deposited in the lower B horizons. reduces the fertility of the upper layers. Laterization- The breakdown of clay particles that result in leaching of silicon from soil due to weathering under warm, moist conditions, leaving oxides of iron and aluminum to predominate (tropical weathering)
28.What does it mean to be poikilosmotic or homeosmotic? How do marine and freshwater fish deal with osmotic regulation?
Poikilosmotic means to have body fluids with a similar osmotic pressure to that of surroundings. This means that the body fluid changes with that of the outside osmotic pressure. Homeosmotic on the other hand means to have a relative constant bodily osmotic pressure independent of osmotic pressure of surroundings. Marine fish (lower salt concentration in body than surroundings) excrete large amounts of solutes, and their gills and kidneys exclude solutes. Freshwater fish (higher salt concentration than surroundings) they actively uptake salts through gills and kidneys and excrete large amounts of water.
61.What are some of the processes that diminish genetic variation in a population? What is a bottleneck? Genetic drift? Founder event?
Processes: Bottlenecks and Founder events, Random Genetic Drift. Bottleneck Effect: Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population. Genetic Drift: Random change in gene frequencies, including loss of alleles, that is likely to occur in small populations because each generation retains just a portion of the gene pool of the previous generation. Founder Effect: Genetic drift attributable to colonization by a limited number of individuals from a parent population.
60.How do we quantify genetic diversity? What is heterozygosity? How is it computed? What is expected heterozygosity? What is the Polymorphism or P?
Quantifying Genetic Diversity: Genetic variation within a population is commonly measured as the percentage of gene loci that are polymorphic or the percentage of gene loci in individuals that are heterozygous. Heterozygosity: The presence of different alleles at one or more loci on homologous chromosomes. Calculation: Sum of all heterozygous genes divided by the total amount of genes. Expected Heterozygosity: 2pq The expected heterozygosity based on the Hardy-Weinberg can be compared to the observed heterozygosity. Determines the number of heterozygotes expected based on the observed allele frequencies. Polymorphism (P) is the proportion of or percentage of genes that are polymorphic.
69. What is an r strategy? K strategy? What is Grime's three end-point model for plants? What are ruderals? Stress tolerators? Describe the trade-off model of life-history evolution.
R strategists- Short-lived, high reproductive rates, early and single stage reproduction, small body size, large offspring #, offspring easily dispersed, minimal parental care. Associated environments: disturbed, unpredictable, highly unfavorable seasons, etc. K strategists: Stable populations of long-lived individuals, slower growth rates, larger body sizes, many reproductive episodes with few offspring per event, much parental investment, often lifetime mating. Associated environment: productive, predictable. Grimes: Competitors, Stress tolerators, and ruderals Competitors: increasing resources and stability. grow large and have long life spans. Stress Tolerators: Increasing stress. Live under extreme environments, grow slowly and conserve resources. Ruderals: Increasing disturbance. Colonize disturbed places or patches, rapid growth, early maturation, high reproductive rates and easily dispersed seeds. Trade-Offs: trade-offs among competing demands and constraints. Trade-off linkages between traits that constrain the simultaneous maximization of two or more traits
What are the modes of thermal energy exchange? Why is the thermal environment important?
Radiation- heat absorbed and then emitted from an object, Conduction-heat transfer through physical contact, Convection-transfer through medium (ie air), Evaporation- transfer through phase change. Organisms use it to keep out of balance with physical environment to maintain homeostasis to keep themselves stable, must counteract these energy exchanges. Thermal environment can control water and energy loss
Why do we have pronounced seasonality at high latitudes? What causes this seasonality?
Seasonality...because those latitudes have a lower annual insolation due to tilt of earth and angle of incidence from the sun. The tilt of the earth. Spring - Sun aim at equator (Spring Equinox March 21, 22) Summer - Northern hemisphere tilts toward sun (Summer solstice June 21, 22) Fall - Sun aims directly at equator (Autumnal Equinox, Sept 21, 22) Winter - Northern hemisphere tilts away from sun (23.5 degree tilt) (Winter Sol Dec 22)
b.What are some adaptations to the cold environment?
See above definitions. Also included: non-shivering thermogenesis, insulation, burrowing.
71. Why separate sexes? Why might we expect to find a 1:1 sex ratio? Discuss the different theories that are used to explain populations with skewed sex ratios (i.e. Trivers-Willard, local resource competition model, sib mating model, etc.).
Separate Sexes: Reduce sibling competition, Reduce parasites/predation risk, Reduce inbreeding depression, Prevent pathogens from getting ahead evolutionarily (Red Queen Hypothesis,) Parental division of labor, Repair damaged genes (Avoid Muller's ratchet), Increased ability to colonize 1:1 The minority sex has the advantage. Each male has 20 sets of genes and the female has 10. What does this even mean? Especially when you're taking into account the role of Barr-bodies in females and how it's a 50/50 chance of which genes are active or not. I think it would be advantageous just based off of the reasons for having separate sexes, especially regarding splitting parent responsibilities. → It means that in this situation, 10 offspring are being produced no matter what. There are 5 females in both situations. When you reproduce, you offer up a set of genes so in this case the female offers up 10 sets. There are only 2 males to mate with the 5 females who will produce 10 kids, so less males get to mate with more females therefore spreading their own gene sets more/passing on their genetic information/increasing their own fitness. Travis-Willard - When resources are low... the females will produce more females Local Resource Competition Model - Sibling Mating Model - There will be more females because a male is able to fertilize a gazillion females during a short period of time. When there are already males, that's when more females will be produced because those already existing males can just mate with the new females. Age differences - Females live longer than males (Mistletoe) Host/Resource Differences - Nutritional Differences -
73.What is sexual dimorphism? What is sexual selection theory as proposed by Darwin (1871)? What is runaway sexual selection? What is female choice? What are the 2 principal hypotheses used to explain female choice? What is the handicap principle? What is parasite-mediated sexual selection?
Sexual Dimorphism: Different exterior phenotypic features of males and females of the same species. eg having a penis and vagina for males and females respectively (or male ducks being brightly colored and females being neutral colored) Sexual Selection Theory: Theorizes that sexual selection could be applied from one sex. Dissimilar sex functions - Energy it takes to develop an egg. Female produces, mRNA, proteins, etc in order to help the egg grow upon fertilization. Males provide little more than a nucleus. Male Competition - They compete to be chosen for fertilization Female Choice - They have a direct choice of a male. Runaway Sexual Selection: When selection is applied by a member of one sex. Direct individual choice by an individual of the opposite sex (males developing outlandish phenotypes to attract females) Female Choice - They have a direct choice of a male Sensory Exploitation Hypothesis: The females like "shiny" things better able to see, they are intrinsically hardwired to desire optimum fitness Genotype Preference Hypothesis: Female preferences based off of male genotypes Handicap principle: elaborate sexual characteristics might handicap the male instead of help, but the fact that the male has reached maturity with this 'handicap' indicates to a female that he has an otherwise superior genotype as he is surviving with this handicap Parasite-Mediated Sexual Selection: Parasites reduce a host's fitness and mates free from parasites might have inherited resistance. Females should choose less parasitized males. For Example: the females selects the prettiest and showiest male bird because his feathers aren't being eaten by parasites and are thus prettier. This may indicate that he might have the ability to resist parasite infection
d. What influence does ectothermy have on body size?
Smaller (more surface area proportionally) They are smaller and elongated. Ectotherms can be in extreme temperatures.
75. What is social dominance? What are dominance hierarchies? What are the types of dominance hierarchies that can be found (i.e. linear)? What is the paradox of social groups?
Social Dominance: social groups and dominance hierarchies- cooperation. Dominance Hierarchies: The pecking order of animals, where position dictates characteristic social behaviors Types: linear, A to B to C to A (triangular,) & web The Paradox: conflict can reduce the fitness of selfish individuals below that of cooperative individuals, so cooperative behaviors should evolve among unrelated individuals but, when most of a social group consists of cooperative individuals, a selfish individual can achieve higher fitness by "cheating".
What is solar radiation? How much solar radiation actually strikes the earth? How much is reflected by atmosphere?
Solar Radiation light that is composed of 4% UV rays, 44% Visible light rays, 52% infrared rays. 2 cal/cm2/min 25% is reflected by atmosphere, 25% is absorbed by atmosphere, 45% is absorbed by surface, and 5% is reflected by surface.
How do animals vary in acquisition of energy and nutrients?
Some nutrients can be absorbed from the sun (vitamin D). Some nutrients are licked off rocks (salt licks.) Energy comes from chemical reactions that take place usually as a result of eating a different animal, or vegetation.
What is the fate of light in an aquatic environment? What is a photic or euphotic zone?
Some water reflects or scatters light. It cannot travel to the bottom of the water. It creates zones. The Photic zone is a layer of water that light can pass through. (photic and euphotic - eu meaning true - are the same) The Aphotic is a zone that sunlight cannot reach
What is an ENSO event? What happens to regional and global climate during an ENSO event? What are climatic conditions like during El Nino and La Nina events? When are hurricanes most common in the Atlantic Ocean?
Southern Oscillation Events - Peru Current a mass of Cold water flows up West coast of south America while El Nino (mass of warm counter current) moves down coast toward Peru. This causes a reversal of the Low and High pressure areas and winds that flow between them. The areas that are normally dry receive lots of rain and vise versa. Drought in Australia and Southern asia. Cooler wetter and often stormy weather in Southern United States. The Polar Jet stream weakens and the warm air settles in canada and alaska. El Nino switches climates but la nina just enhances that normal climate. The dry- dryer, the wet- wetter. They are most common in the summer between July and November and are highly increased during El Nino events.
What are the structural and physical properties of water? Why is water an important part of physical environment?
Structural: Hydrogen bonding, polarity, lattice structure. Water is a covalently bonded polar molecule that combines to form a lattice structure. The physical properties of water include: 1) a high specific heat (1 cal/g/1 degree C) 2) it can be acted upon by the forces of cohesion (surface tension) and adhesion 3) capillary action 4) Viscosity (water has a low viscosity and flows freely) Water is the "solvent of life." It does everything from aiding metabolism in our bodies, to moving energy around the planet, to keeping all the food we eat alive.
What is an ectotherm?
Temperature is regulated by the outside temperatures. An Ectotherm is a conformer. Their body temperature is the same as their surroundings. Ectotherms can regulate their temperature to be at optimal levels but they have to use the external environment to do so
b. What is adhesion-cohesion theory for water uptake in plants?
The adhesions-cohesion theory for water uptake in plants is based on the theory that plant tissues have tiny capillaries or pathways that allow the use of the forces of adhesion and cohesion to draw the water up from the roots to the stem and to the leaves up to the top of the plant.
What are the characteristics of an urban climate?
The climate in an urban place is warmer than its surroundings Skyscrapers can cause canyon winds, asphalt absorbs light and gives off heat, places with the highest population usually have the highest temperatures.
c. What is the available water capacity of soil?
The water after gravitational drainage. Awc= field capacity - permanent wilting point
How does vegetation affect microclimates?
The wind travels different in pine tree forest then in aspen like forest. Pine tree forest create a quiet zone at the leeward base of the pines that allow organisms to live in. Can be cooler because of transpiration, shading. Soil more fertile from all the organic matter breaking down.
Why don't the sun's rays strike the earth uniformly? What is annual insolation? How does it vary across the globe?
The earth is a sphere which varies the angle of incidence of the suns rays, the lower the angle the higher the concentration of the suns rays in a smaller area (and vice versa). Annual Insolation is the mean insolation at the top of the earth's atmosphere in a year. It varies by latitude, higher percent closer to equator and low as it spreads out on either side. The total amount of radiation from the sun in a given area.
What is an inversion? How are inversions formed? What are the common types of inversions?
The normal temperature gradient is inverted such that the air is cooler near the surface of the earth - cool air is under warm air They occur most often when a warm, less dense air mass moves over a dense, cold air mass. This can happen for example, when the air near the ground rapidly loses its heat on a clear night. Topography can also pay an effect when cold air comes down and sinks below the warm air into the valley and get trapped there. Subsidence Inversion - Surface air must flow out as subsidence progresses, cool air from aloft begins to settle, Warm and very dry air approaches the surface. Especially with factories - the warm air goes up and traps the rest of the air in, thus also trapping in pollutants. Canyon Winds - After sun goes down, earth loses heat. Surface air cooled. Cool dense air moves down slopes into valleys and gets trapped. Can also occur in cities where tall skyscrapers act as canyons. Coastal Effect - A current of warm air comes in from the ocean Subsidence, radiation, marine frontal canyon
f. What is the permanent wilting point?
The permanent wilting point is the point at which soil moisture potential has dropped beyond the plant's ability to uptake water and the plant cannot recover and will wilt and die. -15 bar as a general rule
e. What is the soil matrix potential?
The soil matrix potential is the force by which a water molecule is attracted to the soil particle. The drier the soil the higher the soil matrix potential.
g. Available water capacity?
The total available water (holding) capacity is the portion of water that can be absorbed by plant roots. AKA - The amount of water which can be absorbed by the plant. This is held between field capacity and wilting point.
Do we see circulation of ocean currents? If so, why do they circulate and in what direction? What are the major currents of the Northern and Southern Hemispheres?
Thermohaline Circulation - changes of the density of water caused by variations in temperature and salinity. They circulate counterclockwise in the southern hemisphere and clockwise in the northern hemisphere. Northern: North Equatorial Current, Gulf Stream, Southern: South Equatorial current, Peru current, Genguela Current Equatorial Counter Current.
67.What are the principal life history traits? Compare and contrast semelparity and iteroparity. What is allocation? What are trade-offs? What are some of the trade-offs that you might expect in nature?
Traits: Size at birth. Growth pattern, Age at maturity, Size at maturity, Number, size and sex ratio of offspring, Age and size specific reproductive investments, Age and size specific mortality schedules, Length of life Semelparity: reproducing once Iteroparity: multiple reproductive periods Allocation: represents a compromise between competing demands. Putting more energy into one thing or another to maximize that thing. Trade-Offs: linkages between traits that constrain the maximization of two or more traits. Offspring size versus number, Current versus future reproductive effort, Age versus size at maturity, Growth versus reproduction, Reproducing once (semelparity) versus multiple reproductive periods (iteroparity)
How is water distributed in the biosphere? What is the water cycle? Can you trace the water cycle?
Water Distribution The water cycle is the way that water is transported around the globe. It goes from clouds and condenses and falls as precipitation, then collects in lakes, rivers, and oceans. It then evaporates or transpires -transpiration occurs when water is lost through plants, as a part of photosynthesis - to form clouds and water vapor and the cycle repeats itself. (Remember: Clouds (condensation) → Rain (precipitation) → Collection (lakes, streams, oceans) → Clouds (transpiration & evaporation)
c. What is water potential?
Water Potential: "Soil" water potential is usually dominated by matric forces, it is the force required to remove the most loosely bound water molecules For example, in very clayey soils or very dry soils, whatever water molecules are left are clinging on tightly to these soil particles (the rest of the water has evaporated or fallen gravitationally). The tighter they are holding on, the greater (more negative) the metric force will be
b. What determines soil structure?
Weathering processes (most influential, how much water runs through this soil, rate of water, climate) Parent material, Age of soil, Topography, Vegetation and other Biot (like worms that aerate the soil and fertilize it through their digestion/excretion).
What are the prevailing winds? What determines the wind directions of these winds (easterlies and westerlies)? At what latitudes do we find these different winds? What determines the strength of these winds?
Westerlies, Northeast trades, Southeast trades and Westerlies (3 convection cells: polar cell, ferrel cell and Hadley cell) The coriolis effect (the rotation of the earth in relationship to the equator) southern hemisphere they rotate counter clockwise and in the northern hemisphere = clockwise. At the equator, 30 degrees north and south, 60 degrees north and south. Angular velocity. The closer to the poles the stronger they are. and the closer to the equator the weaker they are.
What is ecology? Who coined the term? At what levels does an ecologist study?
What is it? The SCIENCE by which we study how ORGANISMS INTERACT IN and WITH the NATURAL WORLD Who Coined it? Ernst Haekel Level: Organism
66. Life history schedules are resolutions of what four major reproductive considerations?
When to begin reproducing (what age) How big of a litter to have at a time How many litters before death How much care to bestow upon young
Compare and contrast the windward vs. the leeward side of mountains.
Windward is wet and full of vegetation the Leeward is dry and hot
What are the ecological differences associated with slope aspect (i.e. north and south-facing slopes)?
north-facing slope has more vegetation because of increased moisture and less direct sunlight. South-facing slope is less hospitable to most plants (north vs. south facing slopes = aspect) The slopes facing north are cooler and more moist while the south facing receive more sunlight exposure making them hot and dry with shrubs only growing there. The smaller the vegetation the warmer it is. Vegetation also influences wind flow different wind patterns for pine trees vs. aspen like trees.