Science 9 Notes 1.6 Communities & Symbiosis PDF

Unit 1 Ecology Science 9 Mr. Yeo 2023-2024 Biology STATEMENT OF INQUIRY FOR UNIT 1 ▸ Human interactions with natural systems can have global consequences. KEY CONCEPT: Systems RELATED CONCEPTS: Interactions, Consequences GLOBAL CONTEXT: Globalization and Sustainability What is an ecological communit...

Unit 1 Ecology Science 9 Mr. Yeo 2023-2024 Biology STATEMENT OF INQUIRY FOR UNIT 1 ▸ Human interactions with natural systems can have global consequences. KEY CONCEPT: Systems RELATED CONCEPTS: Interactions, Consequences GLOBAL CONTEXT: Globalization and Sustainability What is an ecological community? Recall that a community is all of the populations that make up an ecosystem. Describe the community you might find in a tropical rainforest. Competition Because communities live in the same area, they need to compete. When two or more species use the same resources they participate in a biological interaction called competition. Resources for which species compete may include: food water shelter mates nesting sites sunlight soil Niche In order to understand how competition influences communities, it is important to understand an organism’s niche. A niche is the role that an organism plays within its ecosystem- how it affects the ecosystem and vice versa. Example) A jaguar’s niche Native to South America Diet- mice, frogs, fish, turtles, caiman, tapir, deer Reproduction- year round mating, multiple cubs stay with mom for up to 2 years Time of activity- diurnal All of the variables that contribute to how an organism affects its ecosystem makes up its niche. Symbiosis Symbiosis is a close, long-term relationship shared among species (meaning “living together”). There are 4 general types of symbiotic relationships: Predation Mutualism Commensalism Parasitism Predation- the act of one organism killing another for food. Example: bear + salmon Predator – Prey Relationship In many cases, they act to regulate each other E.g. If there are more predators, the population of prey will decrease. Mutualism- relationship in which both participating individuals benefit Examples: Bees & flowers Clownfish & anemones Lichens (algae & bacteria living with fungus) Commensalism- one individual benefits; the other is neither helped nor harmed. Example: cactus wren and cholla cactus Parasitism- symbiotic relationship in which one individual is harmed but the other is benefitted. Parasites usually do not kill their hosts! Example: ticks on a host animal like dogs Coevolution What is coevolution? Back and forth evolutionary adjustments between species. (example: clown fish’s immunity to anemone toxins) Coevolution can be used to explain some of the symbiotic relationships we see today! Coevolution produces a balance among communities – no species overpopulates or overpowers another because they have evolved in such a delicate way. If an entirely NEW species is introduced to a community, it can disrupt this special balance.