FW104 1nd Edition Lecture 5Outline of Last Lecture I. EcologyII. Levels of OrganizationIII. What’s a Species?A.ClassificationIV. HabitatA. FoodB. WaterC. CoverD. SpaceE. OxygenF. Special Needs V. Welfare Factors VI. NicheVII. Principles A. Principle of Competitive ExclusionB. Limiting Factor Principle & Law of Minimum C. Principle of Tolerance Limits OR Shelford’s Law of ToleranceOutline of Current Lecture I. CommunityA. Species Interactions in the Community1. Predation & Prey2. Parasitism3. Mutualism4. Commensalism5. CompetitionB. EcosystemC. Food ChainsD. Food WebsE. EnergyCurrent LectureI. Community These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Definition of Community: assemblage of populations (species) that interact with each other in same environment (VL) … coexisting, interdependent populations of different species. A. Species Interactions in the Community- Co-evolution: species that interact over long time period influence each other’s traits through natural selection- Ex: plant and pollinators, predator and prey = co-evolutionary arms race including Red Queen Hypothesis. 1. Predation & Prey (Symbiotic Relationship)- Natural selection favors the strongest- Some predator offenses = ambush (alligators), stalk (mountain lion), and cooperative hunting (whales, orcas, wolves). - Some prey defenses = speed, agility, armor, and weaponry (Ex: monarch butterflyget poison from milkweed) - Negative feedback system results in cycles with a lag time -2. Parasitism (Symbiotic Relationship)- Slow form of predation- Can be evolutionary stable as long as the host population is not killed off-3. Mutualism (Symbiotic Relationship)- Both species benefit- Ex: video for Ants vs. Acacia trees: Ants benefit the tree from protecting it from vines from growing on it and from other insects that could eat the tree. The Acacia tree benefits the ant by providing the ant nectar for food, cover, and pods to lay their eggs in. -4.Commensalism (Symbiotic Relationship)- One species benefit while other gets no benefit or harm. -5. Competition (Symbiotic Relationship)- Both species compete for food, territory, water in order to survive. -B. Ecosystem - Definition of Ecosystem: the biotic community (living partof ecosystem) & its physical or abiotic (nonliving) environment of matter and energy- Nutrients cycle in the ecosystem- Energy flows in the ecosystemC. Food Chains- Definition of food chain: pathways over which ENERGY flows through an ecosystem- Trophic levels: feeding level within a food chain (VL)- Carnivores: feed on flesh (VL)- Omnivores: feed on plants and flesh (VL)- Herbivores: feed on plants (VL)- Consumers or heterotrophs- Primary producers or autotrophs- Detritivore food chains link in as well D. Foodwebs - Natural systems have more than one route through which energy flows- Food chain can be expanded to include all trophic levelsE. Energy- 2nd law of thermodynamics: as food is passed from one organism to another, the potential energy contained in the food supply is reduced step by step until all of the energy in the system becomes dissipated as heat- Remembering … the first law: energy cannot be created nor destroyed (conservation of energy); it is converted from one form to another- Implications of energy “loss” at each trophic level: “Pyramid of Energy”- “Pyramid of Numbers” (or biomass): determined by energy availability - Big fierce predators have to eat a ridiculous amount of prey to survive given whatis actually available at their trophic