He admitted the fabrication in an interview with the newspaper. The Japanese Archaeological Association disaffiliated Fujimura from its members. A special investigation team of the Association revealed that almost all the artifacts which he had found were his fabrication. Since the discovery of the hoax, only a few sites can tentatively date human activity in Japan to 40,000–50,000 BC, and the first widely accepted date of human presence on the archipelago can be reliably dated circa 35,000 BC. The Japanese Paleolithic is unique in that it incorporates one of the earliest known sets of ground stone and polished stone tools in the world, although older ground stone tools have been discovered in Australia. The tools, which have been dated to around 30,000 BC, are a technology associated in the rest of the world with the beginning of the Neolithic around 10,000 BC. It is not known why such tools were created so early in Japan. Because of this originality, the Japanese Paleolithic period in Japan does not exactly match the traditional definition of Paleolithic based on stone technology (chipped stone tools). Japanese Paleolithic tool implements thus display Mesolithic and Neolithic traits as early as 30,000 BC. The Paleolithic populations of Japan, as well as the later Jōmon populations, appear to relate to an ancient Paleo-Asian group which occupied large parts of Asia before the expansion of the populations characteristic of today's people of China, Korea, and Japan. During much of this period, Japan was connected to the Asian continent by land bridges due to lower sea levels. Skeletal characteristics point to many similarities with other aboriginal people of the Asian continent. Dental structures are distinct but generally closer to the Sundadont than to the Sinodont group, which points to an origin among groups in Southeast Asia or the islands south of the mainland. Skull features tend to be stronger, with comparatively recessed eyes. According to “"Jōmon culture and the peopling of the Japanese archipelago"” by Schmidt and Seguchi, the prehistoric Jōmon people descended from a paleolithic populations of Siberia (in the area of the Altai Mountains). Other cited scholars point out similarities between the Jōmon and various paleolithic and Bronze Age Siberians. There were likely multiple migrations into ancient Japan. According to the Jōmon people were an admixture of two distinct ethnic groups: A more ancient group (carriers of Y chromosome D1a) that were present in Japan since more than 30,000 years ago and a more recent group (carriers of Y chromosome C1a) that migrated to Japan about 13,000 years ago.