Science Books Understanding Horizontal Gene Transfer In 'The Tangled Tree' 8:19am August 11, 2018 Science Books Author Interviews Humans Share URL copied to clipboard! Copyright 2018 NPR. To see more, visit http://www.npr.org/. 300x250 Ad More Weekend Edition Saturday World News Chileans weigh a new constitution by Scott Simon Sports Saturday sports: Serena Williams' dramatic U.S. Open by Tom Goldman 300x250 Ad Support quality journalism, like the story above, with your gift right now. Donate