Being in the right place at the right time, like living in the same college dorm, is a strong predictor of friendship. iStockphoto.com hide caption

itoggle caption iStockphoto.com

These healthy newborn monkeys, Mito and Tracker, developed from embryos containing transplanted DNA. They are named after the dye "mitotracker" used for imaging mitochondria in cells. Oregon National Primate Research Center at OHSU hide caption

itoggle caption Oregon National Primate Research Center at OHSU