The debate over COVID-19's origin is focused on two theories, that humans were first infected by a wild animal or that the virus leaked from a lab. Scientists say the natural transmission theory has been strengthened by new genetic evidence from the market in Wuhan, China, where there was a big COVID outbreak in December 2019. John Yang discussed the report with Katherine Wu of The Atlantic. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok: https://www.tiktok.com/@pbsnews Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe