Long before going to Europe, humans ventured east to Asia

Modern humans reached southern China at least 35,000 years before setting foot in Europe, new fossil finds suggest.

These discoveries provide the best evidence to date that Homo sapiens took its first major strides out of Africa deep in the Stone Age and headed east, staying within relatively warm regions similar to those of its East African homeland.

Excavations in southern China’s Fuyan Cave produced 47 human teeth dating to between 80,000 and 120,000 years ago, paleoanthropologists report October 14 in Nature. The presence of Neandertals in Europe may have helped deter humans’ migration to that continent until around 45,000 years ago, when Neandertal populations started to shrink, says a team led by Wu Liu and Xiu-jie Wu of the Chinese Academy of Sciences in Beijing and María Martinón-Torres of University College London.

Along with harsh European winters unsuited to a species that evolved in tropical Africa, “Neandertals were at least an additional barrier to modern humans’ entrance into Europe,” Martinón-Torres says.

An early H. sapiens presence in China challenges a prominent idea that modern humans began moving eastward out of Africa about 60,000 years ago. It now appears more likely that African H. sapiens dispersed east and south, from the Arabian Peninsula or the eastern Mediterranean, as early as 120,000 years ago, writes archaeologist Robin Dennell of the University of Exeter, England, also in Nature.

A hominid lower jaw previously found at southern China’s Zhiren Cave dates to between 55,000 and 110,000 years ago. Researchers disagree about whether that find comes from a modern human or Homo erectus, a hominid with far older roots in East Asia.

It’s not yet clear whether human teeth from Fuyan Cave represent a variant of H. sapiens that included jaw bones such as the one found in Zhiren Cave, says paleoanthropologist Erik Trinkaus of Washington University in St. Louis. Trinkaus, who coauthored a report on the Zhiren Cave find (SN: 8/25/12, p. 22), suspects ancient humans interbred with other Homo species on the way from Africa to East Asia. As a result, those populations would have displayed some unusual physical traits once they reached China.

Until now, the oldest well-accepted H. sapiens remains in East Asia, dating to 50,000 to 60,000 years ago, came from northern Laos (SN: 5/19/12, p.14). Aside from the Fuyan Cave discoveries, the earliest Chinese H. sapiens fossils come from a northern cave and date to about 40,000 years ago.

Liu and his colleagues dated a stalagmite that formed just above fossil-bearing soil to about 80,000 years ago. That estimate rests on measurements of two radioactive decay products in the stalagmite. Nonhuman animal bones found with the H. sapiens teeth, including remains of extinct predatory cats, have previously been dated at other sites to no more than around 120,000 years ago.

All 47 modern human teeth from Fuyan Cave are relatively small, much like teeth of European H. sapiens from later in the Stone Age and present-day people, the researchers say. Fuyan teeth are shaped more like those of living human populations than like teeth of Neandertals or Asian H. erectus.

Modern humans took southern routes across Asia while other hominids followed northern paths, Liu’s team proposes. When H. sapiens inhabited the Fuyan Cave region in southern China, Neandertal-like hominids dubbed Denisovans lived in northern China (SN: 12/28/13, p. 8).