The history of Eurasia is the collective history of a continental area with several distinct peripheral coastal regions: the Middle East, South Asia, East Asia, Southeast Asia, and Western Europe, linked by the interior mass of the Eurasian steppe of Central Asia and Eastern Europe. Perhaps beginning with the Steppe Route trade, the early Silk Road, the Eurasian view of history seeks establishing genetic, cultural, and linguistic links between Eurasian cultures of antiquity. Much interest in this area lies with the presumed origin of the speakers of the Proto-Indo-European language and chariot warfare in Central Eurasia. Prehistory Lower Paleolithic Fossilized remains of Homo ergaster and Homo erectus between 1.8 and 1.0 million years old have been found in Europe (Georgia (Dmanisi), Spain), Indonesia (e.g., Sangiran and Trinil), Vietnam, and China (e.g., Shaanxi). (See also:Multiregional hypothesis.) The first remains are of Olduwan culture, later of Acheulean and Clactonian culture. Finds of later fossils, such as Homo cepranensis, are local in nature, so the extent of human residence in Eurasia during 1,000,000 - 300,000 ybp remains a mystery. Middle Paleolithic Geologic temperature records indicate two intense ice ages dated around 650000 ybp and 450000 ybp. These would have presented any humans outside the tropics unprecedented difficulties. Indeed, fossils from this period are very few, and little can be said of human habitats in Eurasia during this period. The few finds are of Homo antecessor and Homo heidelbergensis, and Lantian Man in China. After this, Homo neanderthalensis, with his Mousterian technology, emerged, in areas from Europe to western Asia and continued to be the dominant group of humans in Europe and the Middle East up until 40000-28000 ybp. Peking man has also been dated to this period. During the Eemian Stage, humans probably (e.g. Wolf Cave) spread wherever their technology and skills allowed. The Sahara dried up, forming a difficult area for peoples to cross. The birth of the first modern humans (Homo sapiens idaltu) has been dated between 200000 and 130000 ybp (see:Mitochondrial Eve, Single-origin hypothesis), that is, to the coldest phase of the Riss glaciation. Remains of Aterian culture appear in the archaeological evidence. Population bottleneck In the beginning of the last ice age a supervolcano erupted in Indonesia. Theory states the effects of the eruption caused global climatic changes for many years, effectively obliterating most of the earlier cultures. Y-chromosomal Adam (90000 - 60000 BP, dated data) was initially dated