community interactions community: many species interacting in the same environment three types of...
TRANSCRIPT
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 hardware store when…
We see this in the world of business too
…Home Depot opens a few blocks away?
Elephant Seals: Competition for mates
Beachmaster Challenger
Elephant Seals: Competition for mates
resource
resource
resource
resource
Only the beachmaster earns the right to mate with every
female is his territory. A typical harem is around 50-
100 females.
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• Ex: Lichens (fungus and Algae)
Fungus:Obtains nutrients from the algae
Algae:Grows among the cells of the fungus (home)
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
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)
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
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
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
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
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
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
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?