A recent U.S. Forest Service study estimated that the trees planted along California streets provide a billion dollars’ worth of human benefit each year.¹ And that benefit comes cheap. This analysis reveals five tree-related benefits that identify where trees fit in the origins controversy.

After investing so much time and effort to understand how body parts interact, scientists keep turning up new and unforeseen connections—often when they ask the right questions. New and strange developments inspired a team to ask wacky questions about a unique white blood cell called Ly6C^hi. And they found some profound answers.