Community Interactions

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

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

Competitive Exclusion in Paramecia

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

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

Elephant Seals: Competition for mates Beachmaster Challenger

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

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

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

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)

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

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

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

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

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

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

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

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

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?