Bài giảng Environmental Sciences - Chapter 4 Lecture Notes Ecosystems: How They Change

Chapter 4 Lecture Notes  Ecosystems: How They ChangeOutline of Chapter 4Population dynamicsPopulation equilibriumEvolutionSuccessionLiving beyond our meansDynamic EquilibriumEcosystems are constantly changing in order to stay balanced.Succession - One species gradually replaced by another in an ecosystemprimary – new ecosystem where there were no living things before. Cooled lava, receded glacier, mud slidesecondary- ecosystem used to be there. Fire, humans clear an areaAquatic – (type of secondary) lakes taken over by terrestrial ecosystemClimax ecosystem- in balance only changes if major interferenceFires in EcosystemMaintain balance of species and energy in ecosystems over the long run. Beneficial b/c provide nutrients for soilWe avoid natural fires, but the problems like Crown Fires- (not natural) kill the whole tree1988 Yellowstone fires changed climax ecosystems of white bark pine trees to huckle berries. Grizzlies ate bothPrimary successionMust create new soil for plants to growThe first plants to come in are called pioneer speciesThe Basics of Evolutionary ChangeVocabulary * DNA * Chromosome (46) * Gene –Coding region of the DNA * allele (23) – during meiosis, each egg or sperm receives one allele for each geneCentral Dogma: DNA- blueprint RNA- carpenter Protein- house, pieces, wood Each cell in an organism has the instructions.MutationsMutations are changes in DNA. They can occur by: * Normal variation * Chemical * UV * Radiation Genetic Trait- only passed down if an organism reproduces Good or Bad?Why do species change?Selective pressure on DNA mutations from environmental resistance and biotic potentialThe time and space for evolution can be understood by knowing how old the earth is, how long life has been around, and Pangea.SpeciationexampleReproductive IsolationUnderstand how molecular biology (micro) relates to evolutionary change (macro) for each of these vocabulary words:AdaptationGenetic variationGene poolDifferential reproductionBiological evolutionSelective breedingArtificial selectionSelective pressureNatural selectionFitnessEvolution of a new speciesReproductive isolation Chapters 3 and 4 Group Assignment:Research your topic and be prepared to explain the main points of that topic to your classmates tomorrow in a 2-3 slide, less than 5 minute PPT presentation. Include information beyond that found in our textbook.Introduce yourselvesProvide examplesInclude at least one visual (other than the figures)Define vocabulary (check the study guide)Deposit into: teacher inbox/Griffith /APES/Ch 3,4 PPT/your period as “#1 Griffith,Griffith”Rubric for presentation5 points good group practices5 points content correct2 points thorough2 points on time (4-5 minutes)1 point GREAT, impressive, good ideas for remembering the materials15 points possibleGroup TopicsProductivity of Ecosystems Figs 3-14, 3-22Energy flow, biomass pyramid figs 3-15Ecosystem Capital Table 3-2Population interactions and curves figs 4-2, 4-5, 4-6Biotic potential vs. environmental resistance and critical number fig 4-4Keystone species fig 4-7Introduced species figs 4-11, 4-12, 4-13Geological time scale (earth, life, human perspective)Pangaea and tectonic plates fig 4-19Interesting adaptations fig 4-15Aquatic succession Fig 4-22