In July 2018, he was a co-author of a pioneering publication on ancient human prehistoric DNA from several sites in Southeast Asia. The result identified a series of population movements beginning with the arrival of anatomically modern humans over 50,000 years ago and involving at a later date, the expansion of rice farmers from the Yangtze Valley. He is now following this up, in conjunction with colleagues in Denmark, with the analysis of aDNA from his most recently excavated site at Non Ban Jak in Northeast Thailand.