But they have spent ten thousand years crossing them with unknown bacteria: http://www.npr.org/sections/goatsandsoda/2015/05/05/404198552/natural-gmo-sweet-pot

But they have spent ten thousand years crossing them with unknown bacteria: http://www.npr.org/sections/goatsandsoda/2015/05/05/404198552/natural-gmo-sweet-potato-genetically-modified-8-000-years-ago http://www.npr.org/sections/goatsandsoda/2015/05/05/40419855...