found) and ecological changes brought about by Homo led to the further expansion of the brain in the areas of problem-solving, memory etc., ultimately leading to the great behavioral flexibility, highly efficient communication, and ecological dominance of humanity. The biological pre-adaptations of the great apes and earlier primates allowed the brain to expand threefold within just 2 to 2.3 million years of the Pleistocene, in response to increasingly complex societies and changing habitats. Middle Pleistocene The appearance of Homo heidelbergensis about 600,000 years ago heralds a number of other new varieties, such as Homo rhodesiensis and Homo cepranensis about 400,000 years ago. Homo heidelbergensis is a candidate for first developing an early form of symbolic language. Whether control of fire and earliest burials date to this period or only appear during the Middle Paleolithic is an open question. Also, in Europe, a type of human appeared that was intermediate between Homo erectus and Homo sapiens, sometimes summarized under archaic Homo sapiens, typified by such fossils as those found at Swanscombe, Steinheim, Tautavel, and Vertesszollos (Homo palaeohungaricus). The hand-axe tradition originates in the same period. The intermediate may have been Homo heidelbergensis, held responsible for the manufacture of improved Mode 2 Acheulean tool types, in Africa, after 600,000 years ago. Flakes and axes coexisted in Europe, sometimes at the same site. The axe tradition, however, spread to a different range in the east. It appears in Arabia and India, but more importantly, it does not appear in southeast Asia. Transition to the Middle Paleolithic From about 300,000 years ago, technology, social structures and behaviour appear to grow more complex, with prepared-core technique lithics, earliest instances of burial and changes to hunting-gathering patterns of subsistence. Homo sapiens first appeared about 300,000 years ago, as evidenced by fossils found at Jebel Irhoud in Morocco. Lower Paleolithic era by region India Guy Ellcock Pilgrim, a British geologist and palaeontologist, discovered 1.5 million-year-old prehistoric human teeth and part of a jaw indicating that ancient people, intelligent hominins dating as far back as 1,500,000 ybp Acheulean period, lived in the Pinjore region near Chandigarh. Quartzite tools of the lower Paleolithic period were excavated in this region extending from Pinjore in Haryana to Nalagarh (Solan district in Himachal Pradesh). The lands of Gujarat has been continuously inhabited from the Lower Paleolithic (c. 200,000 BP) period. Several sites of stone age are discovered in riverbeds of Sabarmati, Mahi