This resource, authored by David Morrison, contains the National Aeronautics and Space Administration's Astrobiology Institute news story on new evidence of a 251-million year-old impact crater off the western coast of...

This outline of a presentation on extinction reviews the various catastrophic events that could lead to extinction and lists the five great mass extinctions. Climate change is identified as the linking factor and...

What, some ask, was the "last extinction?" It's a fair query indeed, and it happens to be understood as the period approximately 13,000 years ago when large animals were killed off across the North American continent....