Ecological Niches

Introduction

• Ecology: Study of relationships between organisms and their environment.
• The Earth has diverse environments (e.g., urban areas, oceans, deserts), each with organisms adapted to those conditions.
• Key terms: species, population, community, ecosystem.

Key Concepts

Species

• A group of organisms that can interbreed and produce fertile offspring.

Population

• A group of organisms of the same species living in the same area at the same time.

Community

• A group of different populations living and interacting in an area.

Ecosystem

• A community and its abiotic (non-living) environment.

Niches

• Ecological Niche: Unique role and habitat of a species in a community.
• Two components of a niche:
  • Role: Job or function of the organism.
  • Habitat: Where the organism lives, including biotic and abiotic factors.

Types of Niches

• Fundamental Niche: Potential area an organism could occupy.
• Realized Niche: Actual area occupied due to competition and other factors.

Competitive Exclusion Principle

• No two species can occupy the same niche.

Feeding and Nutrition

Types of Organisms

• Eukaryotes, Archaea, Prokaryotes (bacteria).

Feeding Strategies

• Autotrophs: Produce own food (photosynthesis or chemosynthesis).
• Heterotrophs: Consume other organisms for food.
  • Types: Herbivores, Carnivores, Omnivores, Detritivores, Saprotrophs.
• Mixotrophs: Capable of both self-feeding and consuming others.

Dentition and Diet

Human Dentition

• Incisors: Cutting
• Canines: Tearing
• Premolars: Crushing
• Molars: Grinding

Diets

• Herbivores: Large incisors, wide premolars.
• Carnivores: Sharp incisors and canines, serrated premolars.
• Omnivores: Mix of herbivore and carnivore features.

Great Apes and Diets

• Great Apes: Orangutans, Gorillas, Chimpanzees, Bonobos, Humans.
• Diets vary: Frugivores, Folivores, Omnivores.

Adaptations

Predator Adaptations

• Physical: Sight, claws, teeth, movement, sense.
• Behavioral: Ambush, pack hunting, pursuit (speed, persistence).
• Chemical: Venom, pheromones.

Prey Adaptations

• Physical: Camouflage, shells, spines.
• Behavioral: Avoidance, group formation.
• Chemical: Bad taste, poison.

Plant Adaptations

• Light Harvesting: Canopy vs. forest floor strategies.
• Defense Against Herbivores: Thick bark, thorns, chemical irritants.

Herbivore Adaptations

• Long necks, tough tongues, sharp mandibles, regurgitation (ruminants), symbiotic bacteria.

Aerobic and Anaerobic Organisms

Types

• Obligate Aerobes: Require oxygen.
• Obligate Anaerobes: Cannot tolerate oxygen.
• Facultative Anaerobes: Can survive with or without oxygen.

Summary

• Reviewed key concepts of ecology, ecological niches, types of nutrition, and adaptations.
• Examined the relationship between predators and prey, and how plants and herbivores adapt to their environment.
• Explored the classification and dietary habits of great apes and the physiological and chemical strategies plants use to deter herbivores.