Environmental

Recent Posts

Was humankind's first exit from Africa a failed activity?
Posted on 12 Mar 2011 by Thomas H. Clarke, Jr.

Prior posts have noted that the accepted wisdom is that some humans left Africa about 60 thousand years ago, and thereafter migrated all over the world. Now, researchers have found stone tools at a site in the Arabian Peninsula that suggests movement... Read More

Why did the early Earth not freeze when the Sun was up to 30% fainter?
Posted on 23 Jun 2010 by Thomas H. Clarke, Jr.

Many prior posts have reviewed the evolution of life on Earth, and the conflicting evidence that can be identified regarding when oxygen began to be present in significant quantities in the atmosphere. Be that as it may, one critical question has remained... Read More