A predator returns - and reverses decades of aspen decline.
A digital landscape of the American Southwest.
How have humans altered Earth's land surface? See it via satellite.
An "extended family" once lived by Kenya's Lake Turkana.
Athens copes with the aftermath of a devastating fire.
An innovative new technique to harvest stem cells dispenses with sperm.
Impacts from the IPCC's 2007 report.
A recent genomic study reveals how humans first settled the Americas.
Did surviving an ancient primate virus leave humans open to HIV?
The southeastern U.S. burned repeatedly in this season's extreme drought.