The shrinking of an immense swath of Antarctic ice threatens to raise sea level and there may be no stopping it
Ice entombed our planet hundreds of millions of years ago, and complex animals evolved in the greenhouse heat wave that followed
As the U.S. turns over the canal, Panama prepares for visitors
In almost all other species, especially primates, baring one's teeth is a threat or a show of potential force. Are there any cultures in which smiling is not considered friendly?