Southeast Asia was first reached by anatomically modern humans before 60,000 years ago, possibly before 70,000 years ago. The oldest anatomically modern human fossil from Southeast Asia was found in Callao Cave, near Peñablanca, Cagayan, dated to 67,000 years old in 2010. Anatomically modern humans reached Southeast Asia in the course of the Southern Dispersal migration before the formation of a separate East Asian clade, at around 40,000 years ago. The pre-Neolithic Negrito and Australo-Melanesian populations of Southeast Asia were largely replaced by the expansion of Austroasiatic and Austronesian populations, beginning about 5,000 years ago. The division of the Southern East Eurasian lineage of Southeast Asia, and the Northern East Eurasian lineage of East Asia, is made in physiological terms based on dentition, the distinction of "Sundadonty" vs. "Sinodonty". Sundadont dentition is found in the skeletal remains of Jōmon people of Japan, and in living populations of Taiwanese aborigines, Filipinos, Indonesians, Borneans and Malaysians. According to 2016 analysis by C.G Turner II, sundadonty is the paleo-East Eurasian dental morphology which is not connected to the Australo-Melanesian dental morphology. He also shows that sinodonty is predominant in Native Americans. In Asia, the most recent late archaic human fossils were found in China, the Philippines, Malaysia, and Sri Lanka. The artifacts from these sites include partial skeleton, crania, deep skull, and other related skeletons indicate that modern human migrated to Asia earlier than the western theory might have discussed. In 2009, archaeologists discovered the partial cranium and some teeth of a modern human at Tam Pa Ling in mainland Laos, which shed light on the understanding of anatomically modern human migration and evolution in the region during the Late Pleistocene Period. The site is located in Houaphanh Province, around 170 miles north of Vientiane, the capital city of modern Laos. Within this site, only human remains were found, and there is no evidence of human occupation or other artifacts. The radiocarbon dating of the charcoal and the sediment dating analyses identify the remains to date at least c. 56.5 ka, while the dental artifacts from the remains that analyzed by the isotope-ratio measurement indicate c. 63.6 ka. The analysis of the cranium and dentition of the remains suggest that these are the remains of early modern human populations in Southeast Asia. This date is older than the fossils that were found in Niah cave in Malaysia, which offers another explanation for human evolution in Southeast Asia. In addition to the discovery in Laos, there are also a number of human remains and related artifacts found across mainland Southeast Asia in which it suggests the new ideas of the regional Late Pleistocene development as well. More teeth and molars that were found in Thailand and Vietnam sites indicate transitions between H. erectus and H. sapiens. In fact, these remains might indicate the possible interbreeding between H. erectus and H. sapiens, such as the tooth at Wihan Nakin at Chaiyaphum province in Thailand.
