The appropriate answer is habitat destruction. Human activities such as clearing forests are examples of habitat destruction. Adaptive evolution occurs when an organisms features changes to be better suited to its environment. An example of this can be seen by studying Darwin's Finches on the Galapagos Islands. A mass extinction occurs when a large percentage of organism die from a particular region. For example the Permian Extinction saw the demise of over 90 percent of the organisms on earth.
