in summer. The rainfall is very low. This is true of the southwest as well, where steppes, deserts and semi-deserts border on one another. Agriculture is only possible in Siberia without artificial irrigation today between 50° and 60° north. The climatic situation is responsible for the different biomes of the region. In the northernmost section, there is tundra with minimal vegetation. The largest part of Siberia, aside from the mountainous regions, is taiga, northern coniferous forests. In the southwest this becomes forested steppe, and even further south it transitions to grass steppes and the central Asian desert. Before the beginning of the Holocene about 12,000 years ago, the situation was different. During the Weichselian glaciation (from before 115,000 years ago until 15,000 years ago), the tundra extended much further south and an ice sheet covered the Urals and the area to the east of the lower Yenisei. Historical overview Paleolithic Late Paleolithic southern Siberians appear to be related to paleolithic Europeans and the paleolithic Jōmon people of Japan. Various scholars point out similarities between the Jōmon and paleolithic and Bronze Age Siberians. A genetic analyses of HLA I and HLA II genes as well as HLA-A, -B, and -DRB1 gene frequencies links the Ainu people and some Indigenous peoples of the Americas, especially populations on the Pacific Northwest Coast such as Tlingit, to paleolithic southern Siberians. Neolithic (until c. 2400 BC) Finds from the Lower Paleolithic appear to be attested between east Kazakhstan and Altai. The burial of a Neanderthal child found in 1938 shows similarities with the Mousterian of Iraq and Iran. In the Upper Palaeolithic, by contrast, most remains are found in the Urals, where, among other things, rock carvings depicting mammoths are found, in Altai, on the upper Yenissei, west of Lake Baikal and around 25,000 on the shore of the Laptev Sea, north of the arctic circle. The remains of huts have been found in the settlement of Mal'ta near Irkutsk. Sculptures of animals and women (Venus figurines) recall the European Upper Palaeolithic. The Siberian Palaeolithic continues well into the European Mesolithic. In the postglacial period, the taiga developed. Microliths, which are common elsewhere, have not been found. In North Asia, the Neolithic (c. 5500–3400 BC) is mostly a chronological term, since there is no evidence for agriculture or even pastoralism in Siberia during the central European Neolithic. However, the neolithic cultures of North Asia are