1. Ecology: Communities

2. Organizational Hierarchy of Life Most Complex Least Complex sub-atomic particles atom molecule macromolecule organelle cell tissue organ organ system organism population community ecosystem biosphere Non-living Living

3. TermDefinition Population Individuals of one species that occupy a given environment Community All populations in a common environment Ecosystem Organisms in community plus nonliving factors Biosphere Zones of air, land and water at earth’s surface occupied by living things

5. Interactions in Communities -Competition -Competition -Predation -Predation -Symbiosis -Symbiosis

6. Competition Relates to Niche Overlap Degree of competition is proportional to the overlap in ecological niches of competing species Ecological niche = total way of life of all members of a species --Habitat --Physiological needs such as temperature, moisture, nutrients --Behavior --Interactions with other species

7. Outcomes of Competition Competitive Exclusion = One species eliminates the other Grown in Separate Flasks Grown in the Same Flask

8. Outcomes of Competition Resource Partitioning: Use of small differences in environment to fulfill needs

9. Outcomes of Competition Character Displacement: Through natural selection, two species diverge in characteristics that overlap

10. Theoretical vs. Actual Niche Theoretical Niche Defined by Physiological Limits: needs for food, water, temperature Actual Niche Portion of Theoretical Niche that is used, limited by competition

11. Competition Between Two Species of Barnacles for Region Near the Ocean Surface Barnacle C, theoretical niche Barnacle C, Actual niche Barnacle B, theoretical and actual niche

12. Effects of Predation Predation = eating of live organisms Eliminates old and weak individualsEliminates old and weak individuals Regulates numbers of both predators and preyRegulates numbers of both predators and prey Coevolution of predator and preyCoevolution of predator and prey Regulates diversity of populations in communityRegulates diversity of populations in community The sea star Pisaster is a keystone species in aquatic communities in the Pacific Northwest.

13. Population Cycles in Predators and Prey

14. Coevolution of Predator and Prey Camouflage hides prey

15. Symbiosis Close Interaction Between Species Parasitism One helped, other harmed

16. Symbiosis Mutualism Both helped

17. Symbiosis Commensalism One helped, other neither helped nor harmed

18. Will the Monarch Butterfly be affected by the development of herbicide resistant crops?