The collective action of humans - developing and paving over the landscape, clear-cutting forests, polluting rivers and streams, altering the atmosphere's protective ozone layer, and populating nearly every place imaginable - are bringing an end to the lives of creatures across the Earth. Extinction of biological species is not necessarily a phenomenon initiated by human activity, some argue. Although the specific role of extinction in the process of evolution is still being researched and debated, it is generally accepted that the demise of a ....