1. Chapter 2: Living Things in Ecosystems
Section 2.2 – How Species Interact With Each Other
Section 2.3 – Adapting to the Environment

2. Ecosystems are made up of abiotic and biotic factors; as well, biotic components can affect each other in various relationships.

3. In predation, one organism kills and eats another.

4. The organism that is eaten is called the prey, and the one that does the eating is called the predator.

5. Predators tend to feed on young and weak individuals and often limit the size of the prey population.
As populations of prey begin to decline, the predators either switch food sources or die off themselves.

6. COMPETITION
Competition occurs when two or more organisms of the same or different species attempt to use the same limited resource.

7. Species can compete even if they never come into contact with each other.

8. PARASITISM
Parasitism is when an organism lives in or on another organism and feeding on it without immediately killing it.

9. Parasites are the organisms which do the feeding, while the host is the organism being fed off.

10. Mutualism
Mutualism is the cooperative partnership between two species in which both species benefits.

11. Commensalism
Commensalism is the relationship in which one species benefits and the other is neither helped nor harmed.

12. Organisms tend to be well suited for their environment.

13. Kangaroo rats are well suited to the deserts of southwestern U. S
Kangaroo rats are well suited to the deserts of southwestern U.S. – where there is very little water
Eliminate very little water in their feces and urine.
They do not sweat.
Their active at night, when it is cooler.

14. Darwin described this close relationship as Natural Selection.
How does this close match between organisms and their environment come about?
Darwin described this close relationship as Natural Selection.

15. Darwin proposed that over may generations natural selection causes the characteristics of populations to change.

16. This change is known as evolution.

17. With each generation, an organism develops better adaptations – inherited traits that increases an organisms chance of survival.