Edited by Jamie (ScienceAid Editor), Administrator, Taylor (ScienceAid Editor)
In an environment, there are many resources which all living things in it want. They must struggle to gain these resources and this is called competition. It is this that drives natural selection, as organisms must constantly adapt if they are to successfully compete against other species.
The most common resource that animals compete for is food, as this is where they get their energy. Predation is a form of gaining food that involves one organism consuming another. This produces another struggle between the predator and the prey: the predator is attempting to eat as much as possible, while the prey is trying to avoid being eaten. This relationship is dynamic (constantly moving) and can be represented on a predator-prey graph - as is shown below.
This graph shows what is called the predator - prey cycle where the numbers of predator and prey are closely related. And here is why the graph looks as it does:
- 1If the prey population increases, there is more food for the predators so their numbers increase.Advertisement
- 2More prey are eaten, and so their numbers decrease.
- 3Predator numbers fall because there is less food.
- 4If the predator numbers are falling, the prey will become more numerous because they are not as many of them being eaten.
- 5And the cycle continuesAdvertisement
Because of competition, organisms must adapt in order to survive in their habitat. Adaptation comes about through evolution
You can find out how some living things have adapted by look at adaptation This cyclical pattern is also seen between hosts and parasites, because in many ways, you can think about a parasite as a sort of predator.
- If you have problems with any of these steps, ask a question for more help, or post in the comments section below.
Categories : Ecology
Recent edits by: Administrator, Jamie (ScienceAid Editor)