Gigantopithecus cf. G. blacki and Homo tsaichangensis have similar tooth morphology, suggesting related dietary choices and similar geographical range extensions. The discoveries of Gigantopithecus cf. G. blacki and Homo tsaichangensis also revealed that they both inhabited the Tegal-Penghu Biogeographic Province around 250 kya. McMenamin then forms the conclusion that because they lived in the same province and had access to the same food sources, they both had to adapt to a diet rich in bamboo and other surrounding vegetation to survive. McMenamin agrees with a potential explanation provided by Chang, that the Penghu 1 specimen represents a hominin which evolved from a gracile-jawed Homo erectus to better suit its environment, thus affording it to be classified as a separate species called Homo tsaichangensis. Chinese anthropologists Xinzhi Wu and Haowen Tong are not so eager in the adoption of a new species, tentatively assigning the mandible to archaic Homo sapiens, leaving open the possibility of elevating it to a distinct species should more fossils be discovered. In a 2015 paper, Lelo Suvad accepted the validity of the new species H. tsaichangensis.
