On this week’s show: Companion animals such as dogs occupy the same environment we do, which can make them good sentinels for human health, and DNA gives clues to ancient Maya rituals and malaria’s global spread Contributing Correspondent Andrew Curry joins host Sarah Crespi to discuss two very different studies that used DNA to dig into our past. One study reveals details of child sacrifices in an ancient Maya city. The other story is on the surprising historical reach of malaria, from Belgium to the Himalayas to South America.   Next on the show, using our canine companions to track human health. Courtney Sexton, a postdoctoral research fellow in the Department of Population Health Sciences at the Virginia-Maryland College of Veterinary Medicine, talks about what we can learn from these furry friends that tend to be exposed to many of the same things we are such as pesticides and cleaning chemicals.   Finally, in a sponsored segment from the Science/AAAS Custom Publishing Office, Jackie Oberst, associate editor of custom publishing, interviews professors Miriam Merad and Brian Brown about the evolution of immunology in health care. This segment is sponsored by the Icahn School of Medicine at Mount Sinai.   This week’s episode was produced with help from Podigy.   About the Science Podcast   Authors: Sarah Crespi; Andrew Curry   Episode page: https://www.science.org/doi/10.1126/science.zxgwbqo Learn more about your ad choices. Visit megaphone.fm/adchoices