Ardipithecus ramidus and the Paleobiology of Early Hominids
Ardipithecus ramidus and the Paleobiology of Early Hominids
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DOI：
10.1126/science.1175802
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发表时间：
2009-10
期刊：
影响因子：
56.9
通讯作者：
T. White;B. Asfaw;Y. Beyene;Y. Haile-Selassie;C. Lovejoy;G. Suwa;G. Woldegabriel
中科院分区：
文献类型：
--
作者：
T. White;B. Asfaw;Y. Beyene;Y. Haile-Selassie;C. Lovejoy;G. Suwa;G. Woldegabriel
早于南方古猿出现的人科化石稀少而不完整。因此，在我们与黑猩猩最后一个共同祖先之后，我们的血统进化仍然不清楚。在埃塞俄比亚阿法尔裂谷的生态和时间上解决的背景下恢复的Ardipithecus ramidus，现在阐明了早期原始人古生物学和现存非洲猿进化的各个方面。从440万年前的沉积物中发现的110多个标本包括一个部分骨骼，包括头骨、手、脚、四肢和骨盆的大部分。这种人科动物兼有树栖的掌行攀爬和谨慎的攀爬，还有一种比南方古猿更原始的陆生两足动物。Ar. ramidus有一个减少的犬齿/前臼齿复合体和一个小衍生的颅形态，并消耗了主要的C3植物为基础的饮食（植物使用C3光合途径）。它的生态栖息地似乎主要集中在林地。Ar. ramidus缺乏任何典型的悬挂，垂直攀爬，或指关节行走的特征。Ar. ramidus指出，尽管现存的人类和黑猩猩的基因相似，但我们最后共同的祖先可能与任何现存的非洲猿都有很大的不同。原始人和现存的非洲猿都是通过非常不同的进化途径变得高度专业化的。这一证据还阐明了最早人科的直立行走、两足行走、生态、饮食和社会行为的起源，并有助于定义原始人科的基础适应，从而强调了南方古猿的衍生性质。
Hominid fossils predating the emergence of Australopithecus have been sparse and fragmentary. The evolution of our lineage after the last common ancestor we shared with chimpanzees has therefore remained unclear. Ardipithecus ramidus, recovered in ecologically and temporally resolved contexts in Ethiopia’s Afar Rift, now illuminates earlier hominid paleobiology and aspects of extant African ape evolution. More than 110 specimens recovered from 4.4-million-year-old sediments include a partial skeleton with much of the skull, hands, feet, limbs, and pelvis. This hominid combined arboreal palmigrade clambering and careful climbing with a form of terrestrial bipedality more primitive than that of Australopithecus. Ar. ramidus had a reduced canine/premolar complex and a little-derived cranial morphology and consumed a predominantly C3 plant–based diet (plants using the C3 photosynthetic pathway). Its ecological habitat appears to have been largely woodland-focused. Ar. ramidus lacks any characters typical of suspension, vertical climbing, or knuckle-walking. Ar. ramidus indicates that despite the genetic similarities of living humans and chimpanzees, the ancestor we last shared probably differed substantially from any extant African ape. Hominids and extant African apes have each become highly specialized through very different evolutionary pathways. This evidence also illuminates the origins of orthogrady, bipedality, ecology, diet, and social behavior in earliest Hominidae and helps to define the basal hominid adaptation, thereby accentuating the derived nature of Australopithecus.