Studying the Web of Life

1. Studying the Web of Life • Ecology – the study of the interactions between organisms and their environment • Environments have 2 parts: • Biotic – living things in environment • Abiotic – physical factors of environment (water, soil, light, temperature, etc.)

2. Levels of Environmental Organization Organism – single individual

3. Levels of Environmental Organization 2. Population – group of individuals of the same species that live together in the same area at the same time - individuals in a population compete with one another for food, nesting space, and mates

4. Levels of Environmental Organization 3. Community – consists of all the populations of different species that live and interact in an area - different populations in a community depend on each other for food, shelter, and many other things

5. Levels of Environmental Organization 4. Ecosystem – community and its abiotic environment.

6. Levels of Environmental Organization 5. Biosphere – part of the Earth where life exist

7. Living Things Need Energy • All living things need energy to survive. • Organisms can be divided into 3 groups based on how they obtain energy: • Producers – organisms that use sunlight directly to make food • Consumers – organisms that eat producers or other organisms • Decomposers – organisms that get energy by breaking down dead or decaying organisms

8. Producers Use photosynthesis Mostly plants, but also algae and some bacteria

9. Consumers Cannot use sun’s energy directly Herbivore – eats plants Carnivore – eats animals Omnivore – eat both plants and animals Scavengers – feed on bodies of dead animals

10. Decomposers Bacteria and fungi Extract the last bit of energy from dead organisms and produce simpler materials Nature’s recyclers

11. Food Chains Food Chains – represents how the energy in food molecules flows from one organism to the next

12. Food Webs • Food Web – many energy pathways between organisms

13. The loss of energy at each level of the food chain can be represented by an energy pyramid Each level uses 90% of the energy it obtains, so only 10% of the energy is passed along to the next level Energy Pyramid

14. Habitat and Niche • Habitat – the environment in which an organism lives • Niche – an organism’s way of life within an ecosystem • Includes its habitat, food, predators, organisms with which it competes, how the organism affects and is affected by abiotic factors in its environment

15. Interactions with the Environment • An organism interacts with biotic or abiotic factors in its environment that can control the size of its population • Limiting Factors – factors that influence how large a population can grow to • Ex: food, water, living space, other natural resources • Carrying Capacity – the largest population that a given environment can support over a long period of time

16. Interactions Among Organisms • 4 main ways that species and individuals affect each other: • Competition • Predators and Prey • Symbiotic relationships • Coevolution

17. Competition When 2 or more individuals or populations try to use the same limited resource (ex: food, water, shelter, space, sunlight, etc.) Can occur among individuals within a population Can occur between populations of different species

18. Prey – organism that is eaten Predator – organism that eats the prey Predator Adaptations – Canines Claws Camouflage Speed Prey Adaptations – Chemical combatCamouflageSpeedTrickery: false features and mimicry Predators and Prey

19. Symbiosis • Close, long-term association between two or more species • 3 Main Groups • Mutualism • Commensalism • Parasitism

20. Symbiotic relationship in which both organisms benefit Examples: You and a species of bacteria in your intestines Coral and algae Mutualism

21. Symbiotic relationship in which one organism benefits and the other organism is unaffected Examples: Sharks and remoras Commensalism

22. Parasitism • Symbiotic relationship in which one organism benefits while the other organism is harmed • Parasite – organism that benefits • Host – organism that is harmed • Example: • Tomato hornworm and wasps

23. Coevolution Flowers and their Pollinators Acacia Trees and Acacia Ants Long-term change that takes place in two species because of their close interactions with one another Yucca Moth and Yucca Plants