Ecology and Evolution: Key Concepts in Population Interactions

Commensalism

One organism benefits and the other is unaffected

Competition

Organisms compete for the same limited resource

Consumers

Organisms that eat other organisms

Differential Reproduction

Organisms with good traits have more offspring

Evolution

A change in a population over time

Genetic Variation

Differences between individuals in a population

Heterotroph

An organism that must eat other organisms

Inherited Variation

Traits passed from parents to offspring

Mutualism

Both organisms benefit

Parasitism

One organism benefits and the other is harmed

Predation

One organism kills and eats another

Producers

Organisms that make their own food

Autotroph

An organism that makes its own food

Decomposers

Organisms that break down dead organisms

Herbivore

An organism that eats plants

Natural Selection

Organisms with helpful traits survive and reproduce

Overproduction of offspring

Many offspring leads to variation and competition

Inherited variation and survival

Helpful traits are passed on

Struggle to survive

Only some organisms survive due to limited resources

Survival of the fittest

Best adapted organisms survive and reproduce

Predation vs parasitism

Predation kills parasitism usually does not

Importance of symbiotic relationships

Helps maintain ecosystem balance

Most important symbiotic relationship

Predation controls populations

Largest population in a food web

Producers

Smallest population in a food web

Apex predators

Most impactful organism in a food web

Producers because they supply energy