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EVOLUTION and ECOLOGY BIODIVERSITY Climate zones determine communities Figure 5-2 Terrestrial biomes Figure 5-9 Ecological niche An organism’s role in its community Includes what it needs to survive – – – – – Nutrients Light Space (habitat) Oxygen or carbon dioxide Inorganic compounds How it interacts with other species The more available niches there are to fill, the greater the amount of organisms Niche diversification in African Rift Lake Cichlids Model of Cichlid Fish Diversification Other examples of ecology influencing evolution Coevolution: two species evolve in response to each other over time Pollinators and flowering plants Hosts and parasites Predators and prey Symbioses Competition Hammer orchid Predation drives evolution of both predators and prey Predators adaptations Locate, sneak up on & subdue prey Prey adaptations elude & defend horns, speed, coloration spines, thorns, toxins Symbiotic interactions parasitism (-/+) mutualism (+/+) lichens (algae & fungus) commensalism (+/0) barnacles attached to whale Competition can affect niches High tide Species 1 Low tide Chthamalus sp. Species 2 Fundamental Realized niches niches Semibalanus sp. Ecosystems Two Necessities for Survival: Energy Flow and Matter Recycling Producers: Basic Source of All Food Most producers (autotrophs) capture sunlight to produce carbohydrates by photosynthesis: Consumers: Eating and Recycling to Survive Consumers get their food by eating or breaking down all or parts of other organisms or their remains. Herbivores (primary consumers) Carnivores Omnivores Respiration: Getting Energy for Survival Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy for internal reactions. This is done through aerobic respiration or anaerobic respiration. Decomposers and Detrivores Energy Flow Energy flows through an ecosystem Route of energy flow is determined by an ecosystem’s trophic structure. Trophic interactions move energy through an ecosystem Simple example: Humans can impact natural food webs Chemical pollutants Invasive species Overhunting ~2 months Energy Flow in an Ecosystem: Losing Useful Energy in Food Chains and Webs MATTER CYCLING IN ECOSYSTEMS All organisms are made up of organic molecules Carbohydrates Proteins Lipids Nucleic acids Essential nutrients are those that are required to make the organic molecules C, H, N, O, P, S Organic matter cycles within ecosystems (biogeochemical cycles) Both autotrophs and decomposers play vital roles Carbon Cycle: The Nitrogen Cycle: Bacteria in Action Phosphorus cycle