Outline of Last LectureOutline of Current LectureCommunity EcologySpecies InteractionsCommensalismNichesConsumptionParasitismMutualismReviewGradeBuddy Bio Sci 150 1st EditionLecture 20Outline of Last Lecture 1. Population Ecologya. Analysis of Demographyi. Life Historyb. How Populations Growi. Age Structurec. Ecological FootprintOutline of Current Lecture 1. Community Ecologya. Species Interationi. Commensalism1. Nichesii. Consumption iii. Parasitismiv. MutualismCurrent LectureKey TermsCommunities – assemblages of species that interact with each other.Intraspecific – between individuals of the same speciesInterspecific – between individuals of different speciesExploitation competition – organisms compete indirectly through the consumption of a limited resourceInterference competition – individuals interact directly with one another by physical force or intimidationHabitat: where an organism lives; its “address”Niche: ecological role of an organism; its “job”Consumption: one species benefits, other does notParasitism: organisms live on tissue of hostPredation: predator-prey relationshipsHerbivory: animals eat plants- Aposematic coloration => advertises unpalatable preyo Batesian mimicry: unpalatable species is mimicked by a palatable specieso Müllerian mimicry: unpalatable species converge to reinforce warningParasitism - One organism (parasite) feeds off another (host), but does not normally kill it outrightMutualism – a type of interaction that is beneficial to both species involved. (+/+)Community EcologyCommunities are assemblages of species that interact with each other.Species InteractionsCommensalismCommensalism (+/0): beneficial to one; no effect on other- Intraspecific – between individuals of the same species- Interspecific – between individuals of different species- Exploitation competition – organisms compete indirectly through the consumption of a limited resource- Interference competition – individuals interact directly with one another by physical force or intimidationExample: - Intraspecific competition between individuals of the same specieso Interference competition: Each caterpillar physically intimidates the other.o Exploitation competition: Each caterpillar chews as much leaf as it can.- Interspecific competition between different specieso Interference competition: Beetle and caterpillar use physical intimidation.o Exploitation competition: Aphids and caterpillars compete for common resources.NichesEvery species has a unique niche, or set of habitat requirements. - Habitat: where an organism lives; its “address”- Niche: ecological role of an organism; its “job”- Competition occurs when niches overlap.- Competitive exclusion results when niches completely overlap. o The weak competitor is driven to extinctionConsumptionConsumption (+/-): one species benefits, other does not- Parasitism: organisms live on tissue of hosto usually non-lethal; o parasite(+)o host (-)- Predation: predator-prey relationships; o lethal predator (+),o prey (-)- Herbivory: animals eat plantso Herbivore (+), o plant (-)Categories of consumption can be classified according to how lethal they are for the prey and the length of association between consumer and prey- Anti-predator strategieso Chemical defenseso Camouflageo Aposematic coloration => advertises unpalatable prey Batesian mimicry: unpalatable species is mimicked by a palatable species Müllerian mimicry: unpalatable species converge to reinforce warning- Predators can affect prey densities- Regulation requires density-dependent predationParasitismOne organism (parasite) feeds off another (host), but does not normally kill it outright- Parasites outnumber free-living species 4 to 1- insects, ‘worms’, bacteria, viruses- parasites can alter the behavior of hostso “Parasitic gordian worm causes grasshoppers and crickets to take a fatal plunge into water so that the worms can emerge and mate”o which can lead to a decrease in the species amountMutualismMutualism is a type of interaction that is beneficial to both species involved. (+/+)ReviewDifferent types of species interactions- Mutualism- Competition- Consumption (Parasitism, Predation, Herbivory) - CommensalismFundamental/Realized Niches & Competitive