1. Community Interactions

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

3. 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

4. Competitive Exclusion in Paramecia

5. We see this in the world of business too
What happens to the small neighborhood coffee shop store when…

6. We see this in the world of business too
…Starbucks opens a few blocks away?

7. Elephant Seals: Competition for mates
Beachmaster
Challenger

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

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

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

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

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

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

14. Commensalism
Birds: obtain food
Cattle: no benefit
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

15. Commensalism
Barnacle: obtains a home
Whale: no benefit; no harm
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

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

17. 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
Parasitism
Ticks: eat the blood of their host
Host: Fever, aches, rash

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
Parasitism
Ticks: eat the blood of their host
Rocky Mountain Spotted Fever
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
Parasitism
Ticks: eat the blood of their host
Lyme disease
Host: Fever, aches, rash

20. Review What is a community?
Name the 3 types of community interactions.
When do organisms usually compete?
How do predators and prey interact?
Name the 3 types of symbiosis.
How does mutualism, commensalism, and parasitism differ?
How does predation differ from parasitism?