Ancient skull from China may shake up timeline of human evolution
中国出土的远古头骨或改写人类进化时间线
Sept 25 (Reuters) – In 1990, an ancient human skull was unearthed in China’s Hubei Province that was so badly deformed during fossilization that it was hard to gauge its significance. A new analysis now indicates that the skull belongs to an early branch of a sister lineage to our species in a finding that may shake up the understanding of how human evolution unfolded over the past million years or so.
路透社 9 月 25 日电 – 1990 年，中国湖北省出土了一具远古人类头骨，因化石化过程中严重变形而难以评估其价值。最新分析显示，该头骨属于我们物种姊妹谱系的一个早期分支，这一发现可能颠覆对人类近百万年来演化历程的现有认知。
Researchers used sophisticated scanning and digital reconstruction techniques to determine the original shape of the skull, which is between 940,000 and 1.1 million years old, and compared it to more than 100 other human fossils. They said it appears to be the oldest-known member of an evolutionary lineage that included the enigmatic Denisovans who later roamed a wide swathe of Asia and interbred with our species Homo sapiens.
研究人员采用精密扫描与数字重建技术，还原了这具距今 94 万至 110 万年的头骨原貌，并将其与 100 多件其他人类化石进行比对。他们表示，这可能是已知最古老的某个演化谱系成员，该谱系包含后来广泛分布于亚洲并与我们智人杂交的神秘丹尼索瓦人。
The skull, called Yunxian 2, appears to be that of a man possibly 30 to 40 years old, according to paleoanthropologist Xijun Ni of Fudan University and the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, who led the study published on Thursday in the journal Science, opens new tab.
据领导这项研究的复旦大学及中科院古脊椎动物与古人类研究所古人类学家倪喜军介绍，这具名为”郧县 2 号”的头骨属于一名可能 30 至 40 岁的男性。该研究周四发表于《科学》期刊。
Species in the human evolutionary line are called hominins. The skull previously was tentatively classified as belonging to the hominin species Homo erectus, which had body proportions resembling our own but a smaller brain size and different facial features. The researchers said the new analysis showed that the skull exhibited features that indicate it was not Homo erectus.
人类进化谱系中的物种被称为人族。该头骨先前被初步归类为属于人族物种直立人，其身体比例与我们相似，但脑容量较小且面部特征不同。研究人员表示，最新分析显示该头骨呈现的特征表明它并非直立人。
“It has a long, low skull and receding forehead behind a strong browridge, but the estimated brain size is the largest so far for any hominin of that age. The face is big but with flat and forward-facing cheekbones, and a large nose with a projecting nasal bridge, but without the midfacial prominence we find in Neanderthals,” anthropologist and study co-author Chris Stringer of the Natural History Museum in London said.
“它拥有长而低平的头骨，在粗壮眉脊后方是向后倾斜的前额，但其预估脑容量是迄今发现同年代人族中最大的。面部宽大但颧骨扁平朝前，鼻梁突出的宽大鼻子，却缺少我们在尼安德特人中发现的面中部隆起特征，”伦敦自然历史博物馆人类学家、本研究合著者克里斯·斯特林格表示。
The skull had been partially crushed and its shape distorted from pressure and movement in the ground over many years during and after the fossilization process.
该头骨在化石化过程及之后多年间，因地下压力和移动影响而部分碎裂，形状发生扭曲。
The researchers placed the skull in an Asia-centered hominin lineage that includes the species Homo longi, known from fossils including a skull discovered near the Chinese city of Harbin, as well as the Denisovans.
研究人员将该头骨归入以亚洲为中心的人族谱系，该谱系包含由哈尔滨附近发现的头骨等化石所知的龙人，以及丹尼索瓦人。
The skull, Ni said, shares features with the other members of this lineage such as a broad and massive roof of the mouth, flat and low cheekbones, an expanded region at the back of the head and some features of the ear region.
倪称，该头骨具有这一谱系其他成员的特征，如宽阔厚重的上颚、扁平低矮的颧骨、后脑勺扩张区域以及耳部区域的某些特征。
The existence of Denisovans was unknown until researchers in 2010 announced the discovery of their remains in Denisova Cave in Siberia, with fossils later unearthed elsewhere in Asia. Both Denisovans and Neanderthals experienced significant interactions with Homo sapiens, including interbreeding, before vanishing soon after for reasons not fully understood. Because of the ancient interbreeding, many people today from Asia and some other places carry DNA from Denisovans.
直到 2010 年研究人员宣布在西伯利亚丹尼索瓦洞穴发现丹尼索瓦人遗骸前，这一人种的存在一直不为人知，随后在亚洲其他地区也出土了相关化石。丹尼索瓦人和尼安德特人在消亡前都与智人发生过重要互动，包括混血繁衍，但其突然消失的原因至今未明。由于远古时期的基因交融，如今许多亚洲及其他地区人群仍携带丹尼索瓦人的 DNA。
The findings may change the understanding of the path taken by human evolution in the past million years or so involving members of the genus – a group of closely related species – called Homo.
这些发现可能会改变人们对过去百万年间人属（一组密切相关的物种）进化路径的理解。
The researchers proposed that five major branches, or clades, of large-brained humans in Africa, Europe and Asia began diverging from each other more than a million years ago. These branches led to Homo sapiens; Homo longi and the Denisovans; the Neanderthals (Homo neanderthalensis); Homo heidelbergensis, first known from a jawbone found in Germany; and Homo erectus.
研究人员提出，在非洲、欧洲和亚洲存在五大智人分支（或称演化支），它们早在一百多万年前就开始分化。这些分支最终演化成智人、龙人及丹尼索瓦人、尼安德特人、海德堡人（最早通过德国出土的下颌骨确认）以及直立人。
“The Homo longi clade was quite successful in Asia, occupying a very large area with diverse environments for more than one million years. They probably lived in small, isolated groups and had little interaction with other groups. Consequently, they exhibit considerable morphological diversity,” Ni said.
“龙人支系在亚洲相当成功，在超过一百万年的时间里占据了环境多样的大片区域。他们可能以小规模孤立群体的形式生活，与其他群体交流甚少。因此，他们展现出相当显著的形态多样性，”倪喜军表示。
The researchers said the Yunxian 2 skull provides evidence that the process of divergence among the human lineages occurred earlier than previously suggested.
研究人员指出，郧县 2 号头骨为人类谱系分化过程发生时间早于先前推测提供了证据。
“Based on our new discovery, we challenged the old timelines of human evolution,” Ni said.
“基于我们的新发现，我们对人类进化的传统时间线提出了挑战，”倪喜军说道。
The oldest-known Homo sapiens fossils date to roughly 300,000 years ago in Africa. But the researchers proposed that the lineage that led to our species peeled off from the other hominin lineages hundreds of thousands of years earlier – possibly more than a million years ago.
目前已知最古老的智人化石可追溯至约 30 万年前的非洲。但研究人员提出，导致我们这一物种的谱系从其他人族谱系中分离出来的时间要早数十万年——可能超过一百万年前。
Stringer said the skull may help resolve a dilemma called the “Muddle in the Middle,” the perplexing array of human fossils between 300,000 and one million years old.
斯特林格表示，这个头骨可能有助于解决名为”中间期混乱”的难题，即距今 30 万至 100 万年间令人困惑的人类化石序列。
If the Yunxian 2 skull sits close to the origins of both the Homo longi/Denisovan and Homo sapiens lineages, Stringer added, “it may represent one of the most important windows yet into the evolutionary processes that shaped our genus around one million years ago.”
如果云县 2 号头骨确实接近龙人/丹尼索瓦人和智人族系的共同起源点，斯特林格补充道，”它可能代表了迄今为止最重要的窗口之一，让我们得以窥见约一百万年前塑造我们人属的进化过程。”