2. Community Interactions

3. Community: Many species interacting in the same environment Three types of interactions: – Competition – Predation – Symbiosis

4. Competition Defined: challenge for resources – Examples: water, nutrients, light, food Occurs when resources are limited Competitive exclusion principle: no two species can occupy the same niche in the same habitat at the same time

5. Competitive Exclusion in Paramecia

6. We see this in the world of business too What happens to the small neighborhood hardware store when…

7. We see this in the world of business too …Home Depot opens a few blocks away?

8. Elephant Seals: Competition for mates BeachmasterChallenger

9. Elephant Seals: Competition for mates resource Only the beachmaster earns the right to mate with every female is his territory. A typical harem is around 50- 100 females.

10. Predation Defined: when an organism captures and feeds on another organism Predator: hunter Prey: hunted

11. Symbiosis Symbiosis: relationship where two species live closely together Three types – Mutualism – Commensalism – Parasitism

12. Mutualism Mutualism: both species benefit from the relationship Ex: Lichens (fungus and Algae) Fungus: Obtains nutrients from the algae Algae: Grows among the cells of the fungus (home)

13. Mutualism Mutualism: both species benefit from the relationship. Ex: Lichens (fungus and Algae) Ex: Clown fish and anemones Clown fish: Obtains a home and protection Anemone: Eat undigested food scraps

14. Mutualism Mutualism: both species benefit from the relationship. Ex: Lichens (fungus and Algae) Ex: Clown fish and anemones Ex: Cleaner birds and crocodiles Bird: Eat parasites from inside the crocodile’s mouth Crocodile: Gets teeth cleaned (small parasites are eaten by the bird)

15. Commensalism Commensalism – One member of a symbiotic relationship benefits and the other is neither helped or harmed Ex: Cattle and Birds – Birds eat insects stirred up by the cattle Birds: obtain food Cattle: no benefit

16. Commensalism Commensalism – One member of a symbiotic relationship benefits and the other is neither helped or harmed Ex: Cattle and Birds – Birds eat insects stirred up by the cattle Ex: Barnacles and whales – Barnacles grow on whale Barnacle: obtains a home Whale: no benefit; no harm

17. Parasitism Parasitism: One organism benefits and the other is harmed Ex: Tapeworm feeds in a humans intestines absorbing his/her nutrients Tapeworm: obtains nutrients and a home Host: loses nutrients to the tapeworm; nausea, diarrhea, fatugue

18. Parasitism Parasitism: One organism benefits and the other is harmed Ex: Tapeworm feeds in a humans intestines absorbing his/her nutrients Ex: Ticks can pass disease when they bite Ticks: eat the blood of their host Host: Fever, aches, rash

19. Parasitism Parasitism: One organism benefits and the other is harmed Ex: Tapeworm feeds in a humans intestines absorbing his/her nutrients Ex: Ticks can pass disease when they bite Ticks: eat the blood of their host Host: Fever, aches, rash Rocky Mountain Spotted Fever

20. Parasitism Parasitism: One organism benefits and the other is harmed Ex: Tapeworm feeds in a humans intestines absorbing his/her nutrients Ex: Ticks can pass disease when they bite Ticks: eat the blood of their host Host: Fever, aches, rash Lyme disease

21. Review 1)What is a community? 2)Name the 3 types of community interactions. 3)When do organisms usually compete? 4)How do predators and prey interact? 5)Name the 3 types of symbiosis. 6)How does mutualism, commensalism, and parasitism differ? 7)How does predation differ from parasitism?