  We review recent work aimed at modeling species extinction over geological
time. We discuss a number of models which, rather than dealing with the direct
causes of particular extinction events, attempt to predict overall statistical
trends, such as the relative frequencies of large and small extinctions, or the
distribution of the lifetimes of species, genera or higher taxa. We also
describe the available fossil and other data, and compare the trends visible in
these data with the predictions of the models.
