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 An organism’s role in its community Includes Includes what it needs to survive what it needs to survive – Nutrients – Light – Space (habitat) – Oxygen or carbon dioxide – Inorganic compounds How it interacts with other species How it interacts with other species The more available niches there are to fill, the greater the amount of organisms 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 Coevolution: two species evolve in response to each other over time Pollinators and flowering plants Pollinators and flowering plants Hosts and parasites Hosts and parasites Predators and prey Predators and prey Symbioses Symbioses Competition Competition Hammer orchid

Predation drives evolution of both predators and prey Predators adaptations Predators adaptations Locate, sneak up on & subdue prey Locate, sneak up on & subdue prey Prey adaptations Prey adaptations elude & defend elude & defend spines, thorns, toxins horns, speed, coloration

Symbiotic interactions parasitism (-/+) parasitism (-/+) mutualism (+/+) mutualism (+/+) lichens (algae & fungus) lichens (algae & fungus) commensalism (+/0) commensalism (+/0) barnacles attached to whale barnacles attached to whale

Fundamental niches Realized niches High tide Low tide Species 1 Species 2 Competition can affect niches Chthamalus sp. 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: 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. Consumers get their food by eating or breaking down all or parts of other organisms or their remains. Herbivores (primary consumers) Herbivores (primary consumers) Carnivores Carnivores Omnivores Omnivores

Respiration: Getting Energy for Survival Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy for internal reactions. 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. This is done through aerobic respiration or anaerobic respiration.

Decomposers and Detrivores

Energy Flow Energy flows through an ecosystem Energy flows through an ecosystem Route of energy flow is determined by an ecosystem’s trophic structure. Route of energy flow is determined by an ecosystem’s trophic structure. Trophic interactions move energy through an ecosystem Trophic interactions move energy through an ecosystem Simple example:

Humans can impact natural food webs Chemical pollutants Chemical pollutants Invasive species Invasive species Overhunting 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 All organisms are made up of organic molecules Carbohydrates Carbohydrates Proteins Proteins Lipids Lipids Nucleic acids Nucleic acids Essential nutrients are those that are required to make the organic molecules Essential nutrients are those that are required to make the organic molecules C, H, N, O, P, S C, H, N, O, P, S Organic matter cycles within ecosystems (biogeochemical cycles) Organic matter cycles within ecosystems (biogeochemical cycles) Both autotrophs and decomposers play vital roles Both autotrophs and decomposers play vital roles

Carbon Cycle:

The Nitrogen Cycle: Bacteria in Action

Phosphorus cycle