Newfound fossils from China suggest that complex animals were around millions of years earlier than thought, among them possibly our vertebrate ancestors.

In Northwest Alaska, a proposed mining road has become a flashpoint in a region already stressed by climate change. The 211-mile (340-kilometer) Ambler Access Road would cut through Gates of the Arctic National Park and cross 11 major rivers and thousands of streams relied on for salmon and caribou. The Trump administration approved the project this fall, setting off concerns over how the Inupiaq subsistence way of life can survive amid rapid environmental change.

"There is a lot to keep us busy."