250 million years ago, rising greenhouse-gas levels set off catastrophic changes.
Starting Nov. 20, undocumented Cubans found in Mexico will face immediate deportation.
Tens of thousands protested drug violence this weekend. Many blame the president.
The ancient arachnid is on the rebound – so why isn’t the bird that depends upon it?
Anthropologist Brian Fagan uses Earth’s distant past to predict the crises that may lie in its future.