Ecosystems

Charles Darwin and Alfred Wallace

• Developed the Theory of Natural Selection
• Key points:
  • Organisms make adaptations for survival
  • "All species branch off of common ancestors"

Adaptations

• Definition: Changes in organisms that enhance survival in their environment.

Symbiosis

• Definition: A close relationship between different species.
• Types:
  • Mutualism: Both species benefit.
  • Commensalism: One species benefits, the other is unaffected.
  • Parasitism: One species benefits at the expense of the other.

Limiting Factors

• Types:
  • Abiotic (Non-living):
  • Examples: Sunlight, Temperature, Water (humidity, rainfall), Air (gases), Soil (nutrients, type, pH), Minerals, Wind, Climate, Fire, Atmospheric pressure, Salinity
  • Biotic (Living):
  • Examples: Plants (trees, grasses), Animals (insects, mammals), Bacteria, Fungi, Protists, Dead organisms, Waste products

Carrying Capacity

• Definition: Maximum population size that an environment can sustain.

Growth Types

• Exponential Growth: Rapid increase without limits.
• Logistic Growth: Growth that levels off as it approaches carrying capacity.

Trophic Levels

• Herbivores: Only obtain energy from plants.
• Carnivores: Only obtain energy from animals.
• Omnivores: Obtain energy from both plants and animals.

Producers and Consumers

• Producers: Organisms that create their energy (e.g., plants).
• Consumers: Organisms that obtain energy from other living things.

Food Chain and Rule of 10%

• Food Chain: Illustrates the energy flow in an ecosystem.
• Rule of 10%: Only 10% of energy is passed to the next trophic level in the energy pyramid.