There is some evidence that modern humans left Africa at least 125,000 years ago using two different routes: through the Nile Valley heading to the Middle East, at least into modern Palestine (Qafzeh: 120,000–100,000 years ago); and a second route through the present-day Bab-el-Mandeb Strait on the Red Sea (at that time, with a much lower sea level and narrower extension), crossing to the Arabian Peninsula and settling in places like the present-day United Arab Emirates (125,000 years ago) and Oman (106,000 years ago), and possibly reaching the Indian Subcontinent (Jwalapuram: 75,000 years ago). Although no human remains have yet been found in these three places, the apparent similarities between the stone tools found at Jebel Faya, those from Jwalapuram and some from Africa suggest that their creators were all modern humans. These findings might give some support to the claim that modern humans from Africa arrived at southern China about 100,000 years ago (Zhiren Cave, Zhirendong, Chongzuo City: 100,000 years ago; and the Liujiang hominid (Liujiang County): controversially dated at 139,000–111,000 years ago ). Dating results of the Lunadong (Bubing Basin, Guangxi, southern China) teeth, which include a right upper second molar and a left lower second molar, indicate that the molars may be as old as 126,000 years. Since these previous exits from Africa did not leave traces in the results of genetic analyses based on the Y chromosome and on MtDNA (which represent only a small part of the human genetic material), it seems that those modern humans did not survive in large numbers and were assimilated by our major antecessors. An explanation for their extinction (or small genetic imprint) may be the Toba eruption (74,000 years ago), though some argue it scarcely impacted human population.