Human earth shapers/ETHS101/Ecology and Evolution/Respone to Environmental Change

=The Four ways=

The key ideas are:


 * The "four ways" explain how species and organisms respond to environmental change


 * Species can tolerate change in situ if the change is within their niches. Species can have broad niches in one dimension but narrow niches in another, which means that a big change for one species might be small for another species. Species may also tolerate some conditions outside their niches, but only for a short period.


 * Species can move to areas with suitable habitat. Species have different capacities to disperse. Some kinds of landscape (e.g. hilly ones) can make it easier to disperse.


 * Species can evolve (adapt) to be able to tolerate the change. Evolution is slow, and the rate depends on how much genetic variation there is and some other things.


 * Species can go extinct if they can't tolerate, migrate or adapt. Chance also plays a part because species usually become rare before they go extinct.

The future of life on earth really depends on which combination of the four ways each species follows!

Evironmental change
In this Learning Pathway, we ask the question: what happens to organisms if the environment changes. This mini lecture explores the basic ideas that explain how species and organisms respond to environmental change (such as current climate change).