1. Ecological Interactions

2. What are some ecological interactions?
Population – group of individuals of the same species living in the same area, potentially interacting
Community – group of populations of different species living in the same area, potentially interacting
What are some ecological interactions?

3. Why are ecological interactions important?
Interactions can affect distribution & abundance.
Interactions can influence evolution.
Think about how the following interactions can affect
distribution, abundance, and evolution.

4. Types of Ecological Interactions
competition
predation
parasitism
mutualism
commensalism
symbiosis

6. Competition – two species share a requirement for a
limited resource  reduces fitness of one or both species

7. Predation – one species feeds on another  enhances fitness of predator but reduces fitness of prey
herbivory is a form of
predation

8. Parasitism – one species feeds on another  enhances fitness of parasite but reduces fitness of host

9. Mutualism – two species provide resources or services
to each other  enhances fitness of both species

10. Commensalism – one species receives a benefit from another species  enhances fitness of one species; no effect on fitness of the other species

11. Symbiosis – two species live together  can include
parasitism, mutualism, and commensalism

12. Organizing Ecological Interactions
effect on species 1
predation
herbivory
parasitism + -
commensalism
mutualism
effect on
species 2
competition