The Ainu are indeed cold adapted. Ainuid Australoid types were widespread over much of Asia from 9,000-2,000 years. Some of them helped populate Australia (the Murrayans). Proto-Ainuids (Jomons) are in Thailand 16,000 years ago. They left by boat, moved through the Philippines and settled there, and then went up to the Ryuku Islands to settle in Japan 14,000 YBP or so where they form the Jomon People. The homeland of the Jomons is in Thailand.