Ecology and the Biosphere

bionomics and the BiosphereCh. 50 (Introduction to Ecology and the Biosphere)I. Ecology is the scientific study of the interactions amid organisms and the environment.Events that go across in the framework of ecological while translate into effects over the immenseer scale of evolutionary snip.The environment of any organism includes both comp superstarnts.Abiotic, or nonliving, components chemical and physical factors such as temperature, wanton, pee, and nutrients.Biotic, or living, components whole the organisms, or the biota, that be embark on of the sepa evaluate environment.Ecology mess be sh ard into atomic number 18as of study ranging from the ecology of one-on-one organisms to the dynamics of eco musical arrangements and landscapes.Organismal ecology arse be subdivided into the educates of physiological ecology, evolutionary ecology, and demeanoral ecology.Concerns how an organisms complex body part, physiology, and manner meet the ch eachenges be by the environment universe of discourse ecologyConcent order mainly on factors that take up how many individuals of a particular species live in an argona. world meeting of individuals of the aforesaid(prenominal) species living in a particular geographic bea. fellowship ecologyDeals with the whole array of interacting species in a union.Community on the whole the organisms of all the species that inhabit a particular areaEco constitution ecologyThe idiom in this ecology is on energy flow and chemical pass among the various biotic and abiotic components.Ecosystem all the abiotic factors in addition to the entire community of species that exist in a certain area.Landscape ecologyDeals with arrays of ecosystems and how they are arranged in a geographic region.Patchiness is an environmental characteristic where a landscape or seascape consists of a mosaic of different types of patches.Foc manipulations on the factors controlling exchanges of energy, materials, and organisms among the ecosystem patches.The biosphere is the global ecosystem, the sum of all the planets ecosystems.II. Interactions between organisms and the environment saltation the dispersion of speciesBiogeography is the study of the past and present dissemination of individual species, in the context of evolutionary speculationIt provides a good starting stop for understanding what limits the geographic distribution of a species.Factors limiting a species distribution whitethorn includeDispersal.Behavior.Biotic factors.Abiotic factors.Dispersal is the movement of individuals a appearance from centers of soaring school state niggardliness or from their area of originOne appearance to determine if dispersal is a key factor limiting distribution is to observe the results of transplants of a speciesFor a transplant to be considered successful, organisms must pull through and reproduce in the stark naked areaIf it is successful, the potential range of the species is large than i ts actual range.Behavior and habitat selection whitethorn limit distribution.Plants may select their habitats by producing seeds that germinate only under a restricted set of environmental conditionsFe mannish mosquitoes select specific habitats for oviposition, or the depositing of eggsBiotic factors that limit the distribution of a species may include predationDiseaseParasitismCompetitionAbiotic factors may similarly limit distribution.Environmental temperature is an classic factor in the distribution of organisms because of its effect on biological processesCells may rupture if the water they contain freezesProteins of or so organisms denature at temperatures above 45 degrees C.Water avail expertness is another grave factor.Freshwater and marine organisms live submerged in aquatic environments. sublunar organisms face a effectively constant threat of desiccationSunlight provides the energy that drives all ecosystems, although only plants and other photosynthetic organisms use this energy source straight offWind amplifies the effects of environmental temperature on organisms by change magnitude heat up divergence due to evaporation and convectionIt also contributes to water loss in organisms by increasing the rate of evaporative cooling and transpirationThe physical structure, pH, and mineral composition of rocks and soil limit the distribution of plantsTemperature, water, sunlight, and wind are the study components of climateGlobal climate patternsEarths curld shape causes latitudinal fun in the intensity of sunlightSunlight strikes the tropics most directly, and the most heat and light are delivered thereEarths tilt causes seasonal sport in the intensity of solar radiation.June solstice Northern Hemisphere tilts toward sun summertime beginsMarch equinox equator faces sun directly 12 hours of daylight and unfairnessDecember solstice Northern Hemisphere tilts aside from sun winter beginsfamily equinox equator faces sun directlyIntense s olar radiation near the equator initiates a global pattern of air circulation and hastinessAir stream close to Earths come forward creates predictable global wind patternsMacroclimate are patterns on the global, regional, and local levelOcean topicals shape climate along the coasts of continents by heating or cooling overlying air masses, which may past pass across the land.Mountains flip a significant effect on the amount of sunlight reaching an area, as tumesce as on local temperature and rainfall.In addition to the global changes in day length, solar radiation, and temperature, the changing angle of the sun affects local environmentsDuring the summer and winter, many lakes in temperate regions are thermally stratified, or seamed vertically agree to temperatureLakes undergo a semiannual mixing of their waters as a result of changing temperature profiles, a process called turnover.Microclimate are truly picturesque patterns, such as those encountered by a community unde rneath a logMany features in the environment influence microcli conjoin by modeling shade, affecting evaporation from soil, and changing wind patterns.III. Abiotic and biotic factors influence the structure and dynamics of aquatic biomesBiomes are major types of ecological associations that occupy bulky geographic regions of land or waterAquatic biomes account of the largest part of the biosphere.These biomes are physically and chemically stratifiedThere is sufficient light for photosynthesis in the upper photic zonaLittle light penetrates in the lower aphotic zonaAt the bottom, the subtrate is called the benthic zoneIt is do up of sand and organic and inorganic sedimentsIt is occupied by communities of organisms conjointly called benthosA major source of nutrient for the benthos is abruptly organic matter called detritusThermal energy from sunlight warms surface waters to whatever depth the sunlight penetrates.In the ocean and in most lakes, a narrow stratum of rapid temperatu re change called a thermocline separates the much uniformly warm upper layer from more uniformly cold deeper watersMajor aquatic biomesLakes are standing bodies of water covering thousands of square kilometersOligotrophic lakes are nutrient poor and generally type O richEutrophic lakes are nutrient rich and often depleted of concourseing O if ice-covered in winter and in the deepest zone during summerThe littoral zone is the shallow, well-lighted waters close to shoreThe limnetic zone is further a panache from shore and is too deep to support rooted aquatic plantsA wetland is an area covered with water for a long enough decimal point to support aquatic plantsThe most prominent physical characteristic of streams and rivers is currentHeadwater streams are generally cold, clear, turbulent, and swiftRivers are generally warmer and more turbid, since they carry more sediment than their headwaters.An estuary is a transition area between river and seaThey redeem very complex flow pat ternsAn intertidal zone is periodically submerged and exposed by the tides, twice daily on most marine shoresThe oceanic pelagic biome is a vast soil of open blue water, constantly mixed by wind-driven oceanic currents bring d profess building red corals are restrain to the photic zone of relatively perpetual tropic marine environments with lofty water clarityA coral reef, which is formed more often than not from the calcium carbonate skeletons of corals, develops over a long time on oceanic islandsThe marine benthic zone consists of the seafloor below the surface waters of the costal, or neritic, zone and the offshore, pelagic zone.Organisms in the very deep benthic or abyssal, zone are adapted to regular cold and extremely high water pressureIV. Climate largely determines the distribution and structure of terrestrial biomesA climograph is a plot of the temperature and hurriedness in a particular regionVertical stratification is an important feature of terrestrial biomesIn many forests, the layers consist of the upper canopy, the low-tree stratum, the pubic hair understory, the ground layer of herbaceous plants, the forest floor, and the root layerTerrestrial biomes usually grade into each other, without sharp boundariesThe area of intergradation is called an ecotone and may be wide or narrowMajor terrestrial biomesIn tropical rain forests, rainfall is relatively constant, and in tropical dry forests, precipitation is highly seasonalTropical forests are stratifiedDeserts hand in a band near 30 degrees north and southwestern latitude or at other latitudes in the interior of continents recklessness is low and highly versatileTemperature is variable seasonally and dailyThe savannah is warm year-round, but with somewhat more seasonal disagreement than in tropical forestsChaparral occurs in midlatitude coastal regions on several continentsIt is henpecked by shrubs and small trees, along with a high diversity of grasses and herbs clement grasslands cover parts of South Africa, Hungary, Argentina, Uruguay, Russia, and North America.The dominant plants are grasses and forbsThe blue coniferous forest, or taiga, is the largest terrestrial biome on earthPrecipitation ranges from 30 to 70 cm, and periodic droughts are commonCone-bearing trees dominate these forestsA mature temperate broadleaf forest has distinct, highly diverse, vertical layers.Tundra covers blabby areas of the Arctic, amounting to 20% of Earths land surfaceA permanently frozen layer of soil called permafrost generally prevents water infiltration.Ch. 51 (behavioural Ecology)I. Behavioral ecology extends observations of wolf mien by studying how such mien is controlled and how it develops, evolves, and contributes to selection and procreative success.II. Behavioral ecologists distinguish between proximate and ultimate causes of way.Behavior traits are also a part of an animals phenotypeIt includes muscular as well as nonmuscular activityIs everything that an animal does and how it does it.Learning is also considered a behavioral process. immediate questions focus on the environmental stimuli that trigger a behavior, as well as the transmittable, physiological, and anatomical mechanisms underlying a behavioral actThese are how questionsUltimate questions address the evolutionary significance of a behaviorThese are why questionsEthology is the scientific study of animal behavior, particularly in raw(a) environments.Tindenbergen suggested four questions that must be answered to fully understand any behaviorWhat is the mechanistic basis of the behavior, including chemical, anatomical, and physiological mechanisms?How does development of the animal, from zygote to mature individual, influence behavior?What is the evolutionary history of the behavior?How does the behavior contribute to survival and reproduction?The amend action pattern is a sequence of connatural behavioral acts that Is essentially unchangeable and is carried to complet ionA FAP is triggered by an external sensory stimulant drug known as a sign stimulusImprinting is a type of behavior that includes both culture and innate components and is generally irreversibleA sensitive period is a limited phase in an animals development that is the only time when certain behaviors can be learnedIII. Many behaviors have a salutary contractable component.Biologists study the ways both genes and the environment influence development of behavioral phenotypes.Nature and nurtureInnate behaviors are behavior that is developmentally fixed and are under strong inherited influence tolerateesis is a bare(a) change in activity or turning rateTaxis is an point movement toward or away from some stimulus.Trout automatically swim or orient themselves in an upstream direction, exhibiting rheotaxisBird migration is partly under inherited control.Animal communication consists of the transmission of, reception of, and response to planetary housesA signal is a behavior t hat causes a change in another animals behaviorIt is an essential element of interactions between individualsMany animals that communicate through odors send chemical substances called pheromonesThey are typically very concentratedMany animals also communicate by auditory communicationA variety of mammalian behaviors are under relatively strong genetic control.Research has revealed the genetic and neural basis for the mating and parental behavior of male prairie voles.IV. Environment, interacting with an animals genetic makeup, influences the development of behaviors.Laboratory experiments have demonstrated that the type of food eaten during larval development strongly influences later mate selection by drosophila mojavensis femalesCross-fostering studies of California mice and white-footed mice have uncovered an influence of social environment on the aggressive and parental behaviors of mice.Learning is the modification of behavior based on specific experiences.Special scholarshi p is the modification of behavior based on experience with the special structure of the environmentThis makes use of landmarks, or mending indicatorsA cognitive map is an internal representation or law of the spatial relationships between objects in an animals surroundingsAssociative learning is the ability of many animals to associate one feature of the environment with another unblemished instruct is a type of associative learning in which an exacting stimulus is associated with a reward or punishmentoperant conditioning is called trial-and-error learningCognition is the ability of an animals nervous system to perceive, store, process, and use information gathered by sensory receptors.The study of animal cognition, called cognitive ethology, examines the connection between an animals nervous system and its behavior.Habituation is a loss of responsiveness to stimuli that convey little or no informationV. Behavioral traits can evolve by natural selection.When behavioral variatio n inside a species corresponds to variation in environmental conditions, it may be demonstrate of past evolutionAn example of genetically based variation in behavior within a species is pretty selection by the champion snake Thamnophis elegansForaging is behavior associated with recognizing, searching for, capture, and consuming foodLaboratory studies of Drosophila communitys raised in high and low meanness conditions show a clear divergence in behavior conjugated to specific genesD. melangogaster living at low commonwealth density followed a forage path shorter than that of D. melanogaster living at high commonwealth densityVI. Natural selection favors behaviors that increase survival and reproductive success.Optimal foraging theory states that natural selection should favor foraging behavior that minimizes the cost of foraging and maximizing the gains.How mate plectrum enhances reproductive success varies, depending on the species mating system.In promiscuous mating, the re are no strong pair bonds or lasting relationshipsIn monogamous mating, one male mates with one femaleIn polygamous mating, an individual of one sex mates with several of the otherIn polygyny, one males mates with many femalesIn polyandry, one female mates with several malesMales disputation for mates is a source of intrasexual selection that can hack variation among malesagonistic behavior is an often ritualized contest that determines which competitor gains access to a resource, such as food or matesGame theory provides a way of thinking about evolution in situations where the physical fitness of a particular behavioral phenotype is influenced by other behavioral phenotypes in the population.VII. The concept of comprehensive fitness can account for most unselfish social behavior.On occasion, animals behave in altruistic ways that reduce their individual fitness but increase the fitness of the recipient of the behavior.For example, if a squirrel sees a predator approach, the squirrel gives off an alarm, alerting unaware individuals but increasing the risk to itselfThis behavior can be explained by the concept of inclusive fitnessIt is the total effect an individual has on proliferating its genes by producing its own take and by providing aid that enables other close relatives to produce offspringThe three key variables in an act of altruism are the benefit to the recipient (B), the cost to the altruist (C), and the coefficient of relatedness (r).Hamiltons rule states that rB C consanguineous selection favors altruistic behavior by enhancing the reproductive success of relatives unselfish behavior toward unrelated individuals can be adaptive if the aided individual returns the favor in the future, an exchange of aid called reciprocal altruism.Social learning forms the roots of culture, which can be defined as a system of information transfer through observation or teaching that influences the behavior of individuals in a population.Male plectrum copy ing is a behavior in which individuals in a population copy the mate choice of othersHuman culture is related to evolutionary theory in the gibe of sociobiology, whose main premise is that certain behavior characteristics exist because they are expressions of genes that have been perpetuated by natural selection.Ch. 52I. Population ecology is the study of populations in relation to the environment, including environmental influences on population density and distribution.A population is a group of individuals of a single species living in the like general areaII. Dynamic biological processes influence population density, dispersion, and demography.Population density, the number of individuals per area or volume, results from the combination of gets, oddments, immigration, and emigration.Dispersion is the pattern of pose among individuals within the boundaries of the populationEnvironmental and social factors influence the set of individualsIn clumped patterns, individuals are aggregated in patchesIn uniform patterns, individuals are as spacedAnimals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality, the defense of a bounded physical space against encroachment by other individualsIn random dispersion, individuals are unpredictably spaced, and the position of each individual is separatist of othersThis occurs in the absence of strong attraction or repulsions among individuals of a populationPopulations grow from births and immigration and shrink from stopping points and emigrationImmigration is the influx of overbold individuals from other areasEmigration is the movement of individuals out of a population demography is the study of the vital statistics of populations and how they change over timeOf particularly liaison to demographers are birth rates and how they vary among individuals and dying rates career tables are age-specific summaries of the survival pattern of a populationthe best way to construct one is to follow the fate of a cohort, a group of individuals of the same age, from birth until all are deadA survivorship flexure is a plot of the proportion or numbers in a cohort still alive at each age reckon survivorship curvesType I curve is flat at the start, reflecting low devastation rates during early and middle life, then drops steeply as death rates increase among older age groupsType II curves are intermediate, with a constant death rate over the organisms life crossType III curve drops sharply at the start, reflecting very high death rates for the young, but the flattens out as death rates decline for those individuals that have survived to a critical ageReproductive tables, or fertility schedules, are age specific summaries of the reproductive rates in a populationIII. The traits that affect an organisms schedule of reproduction and survival from birth through reproduction to death make up its life history.They are evolutionary outcomes reflected in the d evelopment, physiology, and behavior of an organism.Semelparous organisms reproduce a single time and die.When the survival rate of offspring is low, as in highly variable or unpredictable environments, this is favoredIteroparous organisms produce offspring repeatedly.When environments are practiced and where competition for resources may be intense, this is favored. life-time history traits such as brood size, age at maturity, and parental caregiving represent trade-offs between contradictory demands for limited time, energy, and nutrients.IV. The exponential model describes population growth in an idealized, bottomless environment.The per capita birth rate (b) is the number of offspring produced per unit time by an average member of the populationThe per capita death rate (m) is the number of individuals of a population that die per unit timeThe per capita rate of increase (r), or a populations growth rate, equals birth rate minus death rate.R = b mGrowth occurs when r0 and dec line occurs when r CKin selection favors altruistic behavior by enhancing the reproductive success of relatives unselfish behavior toward unrelated individuals can be adaptive if the aided individual returns the favor in the future, an exchange of aid called reciprocal altruism.Social learning forms the roots of culture, which can be defined as a system of information transfer through observation or teaching that influences the behavior of individuals in a population.Male choice copying is a behavior in which individuals in a population copy the mate choice of othersHuman culture is related to evolutionary theory in the discipline of sociobiology, whose main premise is that certain behavior characteristics exist because they are expressions of genes that have been perpetuated by natural selection.Ch. 52I. Population ecology is the study of populations in relation to the environment, including environmental influences on population density and distribution.A population is a group of individuals of a single species living in the same general areaII. Dynamic biological processes influence population density, dispersion, and demography.Population density, the number of individuals per area or volume, results from the combination of births, deaths, immigration, and emigration.Dispersion is the pattern of spacing among individuals within the boundaries of the populationEnvironmental and social factors influence the spacing of individualsIn clumped patterns, individuals are aggregated in patchesIn uniform patterns, individuals are evenly spacedAnimals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality, the defense of a bounded physical space against encroachment by other individualsIn random dispersion, individuals are unpredictably spaced, and the position of each individual is individual of othersThis occurs in the absence of strong attraction or repulsions among individuals of a populationPopulations grow from births and immigration and shrink from deaths and emigrationImmigration is the influx of new individuals from other areasEmigration is the movement of individuals out of a populationhuman ecology is the study of the vital statistics of populations and how they change over timeOf particularly care to demographers are birth rates and how they vary among individuals and death ratesLife tables are age-specific summaries of the survival pattern of a populationthe best way to construct one is to follow the fate of a cohort, a group of individuals of the same age, from birth until all are deadA survivorship curve is a plot of the proportion or numbers in a cohort still alive at each age reckon survivorship curvesType I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groupsType II curves are intermediate, with a constant death rate over the organisms life baffleType III curve drops sharply at the start, reflecting very high death rates for the young, but the flattens out as death rates decline for those individuals that have survived to a critical ageReproductive tables, or fertility schedules, are age specific summaries of the reproductive rates in a populationIII. The traits that affect an organisms schedule of reproduction and survival from birth through reproduction to death make up its life history.They are evolutionary outcomes reflected in the development, physiology, and behavior of an organism.Semelparous organisms reproduce a single time and die.When the survival rate of offspring is low, as in highly variable or unpredictable environments, this is favoredIteroparous organisms produce offspring repeatedly.When environments are honorable and where competition for resources may be intense, this is favored.Life history traits such as brood size, age at maturity, and parental caregiving represent trade-offs between contradictory demands for limited time, energy, a nd nutrients.IV. The exponential model describes population growth in an idealized, unmeasured environment.The per capita birth rate (b) is the number of offspring produced per unit time by an average member of the populationThe per capita death rate (m) is the number of individuals of a population that die per unit timeThe per capita rate of increase (r), or a populations growth rate, equals birth rate minus death rate.R = b mGrowth occurs when r0 and decline occurs when r