Coddled puppies don’t do as well in school, some trees make their own rain, and the Americas were probably first populated by ancient mariners

This week we hear stories on new satellite measurements that suggest the Amazon makes its own rain for part of the year, puppies raised with less smothering moms do better in guide dog school, and what DNA can tell us about ancient Greeks’ near mythical origins with Online News Editor David Grimm. Sarah Crespi talks to Lizzie Wade about coastal and underwater evidence of a watery route for the Americas’ first people. Listen to previous podcasts. [Image: Lizzie Wade; Music: Jeffrey Cook] Learn more about your ad choices. Visit megaphone.fm/adchoices