EVOLUTION and ECOLOGYEVOLUTION and ECOLOGY

BIODIVERSITYBIODIVERSITY

Climate zones determine communitiesClimate zones determine communities

Figure 5-2Figure 5-2

Terrestrial biomesTerrestrial biomes

Figure 5-9Figure 5-9

Ecological nicheEcological nicheAn organismAn organism’’s role in its communitys role in its community

Includes Includes what it needs to survivewhat it needs to survive

– NutrientsNutrients

– LightLight

– Space (habitat)Space (habitat)

– Oxygen or carbon dioxideOxygen or carbon dioxide

– Inorganic compoundsInorganic compounds

How it interacts with other speciesHow it interacts with other species

The more available niches there are to fill, the The more available niches there are to fill, the greater the amount of organisms greater the amount of organisms

Niche diversification in Niche diversification in African Rift Lake CichlidsAfrican Rift Lake Cichlids

Model of Cichlid Fish Model of Cichlid Fish DiversificationDiversification

Other examples of ecology Other examples of ecology influencing evolutioninfluencing evolution

Coevolution: two species evolve in response to each Coevolution: two species evolve in response to each other over timeother over time Pollinators and flowering plantsPollinators and flowering plants Hosts and parasites Hosts and parasites Predators and preyPredators and prey Symbioses Symbioses Competition Competition

Hammer orchid

Predation drives evolution of Predation drives evolution of both predators and preyboth predators and prey

Predators adaptationsPredators adaptations Locate, sneak up on & subdue preyLocate, sneak up on & subdue prey

Prey adaptationsPrey adaptations elude & defendelude & defend

spines, thorns, toxins

horns, speed, coloration

Symbiotic interactionsSymbiotic interactions

parasitismparasitism (-/+) (-/+) mutualismmutualism (+/+) (+/+)

lichens (algae & fungus)lichens (algae & fungus)

commensalismcommensalism (+/0) (+/0) barnacles attached barnacles attached

to whaleto whale

Fundamentalniches

Realizedniches

High tide

Low tide

Species 1

Species 2

Competition can affect nichesCompetition can affect niches

Chthamalus sp.

Semibalanus sp.

EcosystemsEcosystems

Two Necessities for Survival: Two Necessities for Survival: Energy Flow and Matter RecyclingEnergy Flow and Matter Recycling

Producers: Basic Source of All FoodProducers: Basic Source of All Food

Most Most producers (autotrophs)producers (autotrophs) capture sunlight to capture sunlight to produce carbohydrates by photosynthesis:produce carbohydrates by photosynthesis:

Consumers: Eating and Consumers: Eating and Recycling to SurviveRecycling to Survive

ConsumersConsumers get their food by eating or get their food by eating or breaking down all or parts of other organisms breaking down all or parts of other organisms or their remains.or their remains.Herbivores (primary consumers)Herbivores (primary consumers)CarnivoresCarnivoresOmnivoresOmnivores

Respiration: Getting Energy for SurvivalRespiration: Getting Energy for Survival

Organisms break down carbohydrates and other Organisms break down carbohydrates and other organic compounds in their cells to obtain the organic compounds in their cells to obtain the energy for internal reactions.energy for internal reactions.

This is done through This is done through aerobic respirationaerobic respiration or or anaerobic respirationanaerobic respiration..

Decomposers and DetrivoresDecomposers and Detrivores

Energy FlowEnergy Flow Energy flows through an ecosystemEnergy flows through an ecosystem

Route of energy flow is determined by an Route of energy flow is determined by an ecosystemecosystem’’s s trophic structure.trophic structure.

Trophic interactions move energy through an Trophic interactions move energy through an ecosystemecosystem

Simple example:

Humans can impact Humans can impact natural food websnatural food webs

Chemical pollutantsChemical pollutants

Invasive speciesInvasive species

OverhuntingOverhunting

~2 months

Energy Flow in an Ecosystem: Losing Energy Flow in an Ecosystem: Losing UsefulUseful Energy in Food Chains and Webs Energy in Food Chains and Webs

MATTER CYCLING IN MATTER CYCLING IN ECOSYSTEMSECOSYSTEMS

All organisms are made up of organic moleculesAll organisms are made up of organic molecules CarbohydratesCarbohydrates ProteinsProteins LipidsLipids Nucleic acidsNucleic acids

Essential nutrients are those that are required to make the Essential nutrients are those that are required to make the organic moleculesorganic molecules C, H, N, O, P, SC, H, N, O, P, S

Organic matter cycles within ecosystems (biogeochemical Organic matter cycles within ecosystems (biogeochemical cycles)cycles)

Both autotrophs and decomposers play vital rolesBoth autotrophs and decomposers play vital roles

Carbon Cycle:

The Nitrogen Cycle: The Nitrogen Cycle: Bacteria in ActionBacteria in Action

Phosphorus cycle