经济学人下载:人类进化史-似曾相识

Human evolution
人类进化史

You look familiar
似曾相识

Another piece of humanity’s family tree is fitted into place
南方古猿sediba的发现填补了人类家族谱系的关键空白

Sep 10th 2011 | from the print edition

THE opening scene of Mel Brooks’s film “History of the World: Part One” dispenses with human origins in one line: “And the ape stood, and became man.” Would that it were that easy for palaeontologists to sort out. The transition to humanity is generally agreed to have occurred between Australopithecus, a genus of small-brained, bipedal primates whose most famous member is a fossil nicknamed “Lucy”, and the big-brained species Homo erectus. But pinning down when precisely this took place, and which of the various australopithecine species were involved, has been challenging. Now the most human-like australopithecine found to date is clarifying things—and staking a claim to be the species from which early humans evolved.

梅尔·布鲁克斯执导的电影“世界史：序幕”开场仅用一句话就概括了人类起源：“类人猿直立起来，变成了人类。” 要是古生物学家也能如此轻而易举地阐释人类进化的奥秘就好了。人们普遍认为人类是由南方古猿和直立人之间的某个物种演化而来。南方古猿头部较小，属双足灵长类动物，其最有名的家族成员是一具被称做“露西”的化石，比较而言，直立人的头部就大多了。不过，要想确定确切的人类演化时间和哪些南方古猿物种参与了演化，仍是极具挑战性的课题。目前，迄今为止发现的与人类最为相似的南方古猿正逐渐解开这团迷雾——它阐明了早期人类是由哪个物种演化而来的。

Fossils of the new species, Australopithecus sediba, were discovered in 2008 in a cave in South Africa. Initial research, led by Lee Berger of the University of the Witwatersrand, in Johannesburg, concluded that the species came too late in the fossil record to be the ancestor of the Homo lineage. This week, however, a range of new research into sediba, again led by Dr Berger, has been published in Science. These studies conclude that sediba did in fact predate Homo erectus and, moreover, that parts of its anatomy are surprisingly similar to modern man.

2008年在南非一个洞穴内发现一个新物种化石，称做南方古猿sediba。约翰内斯堡金山大学的李·伯格尔领导的最初研究结果表明南方古猿sediba在化石记录中出现的年份过晚而无法被认定为人类的祖先。然而本周，李·伯格尔博士领导的一系列关于sediba的最新研究成果在《科学》杂志上发表。这些研究结果表明，南方古猿sediba确实早于直立人存在，并且它的一些骨骼结构与现代人类有着惊人的相似之处。