Introduction to EcologyEcology is the scientific study of the distribution and abundance of organisms, and their interactions with the environment.What do we mean by “scientific study”?Essentially, it goes something like thisA hypothesis is a suggested explanation for a phenomena, based upon a conceptual “working model” of how a system works.· Interestingly, a hypothesis cannot be proven true by an experiment, even when it correctly predicts the outcome.Example-Zonosemata wing markings.3 hypothesesExperimentPredictionsWhat does this data suggest?Ecology has a long history as a historical science, and is becoming an experimental science.Based Upon the Questions they Choose to Ask, Ecologists May Work at One or More of Several Different Levels of Organization:Individuals are single, discrete organisms.Slide 15Populations are groups of organisms of the same species living in the same place.Examples of populations include:Slide 18Communities are assemblages of populations of different species living in the same placeSlide 20EcosystemsSlide 22What is a Species?“Biological Species Concept”Morphological Species ConceptPhylogenetic Species ConceptExample of an ecological hypothesis testSlide 28ResultSlide 30Ecological Time Scales Ecological processes may occur over time scales ranging from days to millennia. The ecological time scale is shorter than the evolutionary time scale, but there is some overlap-populations evolve over time, and this can affect the composition of communities and functioning of ecosystems.Slide 32Slide 33Climate vs. WeatherSlide 35Terrestrial Biomes (some scientists count them differently)Slide 37Major Physical Factors influencing terrestrial biomesSlide 39Slide 40TundraSlide 42Taiga or Coniferous ForestSlide 44DesertSlide 46Chaparral:GrasslandsSlide 49SavannahTemperate Deciduous ForestsSlide 52Tropical Rain ForestsSlide 54Tropical Dry ForestsSlide 56Slide 57Aquatic communities are determined by the availability of sunlight and nutrientsSlide 59Open OceanWetlandsSlide 62For most, but not all groups of organisms, biodiversity increases from the poles to the tropicsHistory affects what species live in an area as well.Slide 65Introduction to Ecology Reading:Freeman,Chapter50.Ecology is the scientific study of the distribution and abundance of organisms, and their interactions with the environment. Theword“ecology”comesfromtheGreekwords“oikos”,meaninghouse,and“logos”,tostudy.What do we mean by “scientific study”? Therearehundredsofdifferentsciences;eachemploysdifferenttechniquesandhasitsownmethodsandstandardsofevidence.Inoneformoranother,the“scientificstudy”ofeverysubjectusesthehypothetico-deductiveapproach.Thisapproachisrathernewhistorically,tracingitsrootsbacktotheEuropeanenlightenmentofthesixteenthandseventeenthcenturies.Essentially, it goes something like this -Ascientist,orgroupofscientists,becomesinterestedinexplainingoneaspectofhowthenaturalworldworks.(Thiscomeseasilyforscientists,aswellasmostpeople,peoplearecurious...)-Bothintentionallyandunintentionally,scientistsconductobservations.(Someobservationsmaybecommonsenseorcenturiesold(i.e.,thetides),othersmayrequirespecializedexperience(variationinscutellarhairnumberondifferentstrainsofDrosophila)Ahypothesisisconstructedbasedonallthepertinentobservations.A hypothesis is a suggested explanation for a phenomena, based upon a conceptual “working model” of how a system works.Goodhypothesesgeneratepredictionsthatcanbetested.Inexperimentalsciences,experimentsaresetuptotestthehypothesis.–Inthehistoricalsciences,additionalevidenceisgatheredintheplaceofexperiments(althoughnotnearlyasincisive,someareasdonoteasilylendthemselvestoexperiments(i.e.,stellarastronomy)).Ifthepredictionsofthehypothesisarenotborneout,thehypothesisisfalsified.-Interestingly, a hypothesis cannot be proven true by an experiment, even when it correctly predicts the outcome. Thisisbecauseaninfinitenumberofhypothesescanusuallybegeneratedthatpredictthesameoutcome.Thestrongesthypothesesareusuallyacceptedastrueifmultipleexperimentsfailtofalsifythem.Thesehypotheses,andtheirunderlyingmodels,formscientific paradigmswhichmaylastforcenturiesorlonger.Scientificparadigmsareexplanationsforhowtheworldworks,theyinspirefutureresearch,butalsolimititsdirectiontocertainavenues.Example-Zonosemata wing markings.Observation-Zonosemataflieshavedarkbandsontheirwings.Theywavethemupanddownwhendisturbed.Basedontheprevailingscientificparadigminbiology(Darwinism)-ErickGreeneasked“Howcouldthebehaviorevolvebynaturalselection?”3