Department of Physical Anthropology, The Cleveland Museum of Natural History, 1 Wade Oval Drive, Cleveland, OH 44106, USA.
Philos Trans R Soc Lond B Biol Sci. 2010 Oct 27;365(1556):3323-31. doi: 10.1098/rstb.2010.0064.
The earliest evidence of Australopithecus goes back to ca 4.2 Ma with the first recorded appearance of Australopithecus 'anamensis' at Kanapoi, Kenya. Australopithecus afarensis is well documented between 3.6 and 3.0 Ma mainly from deposits at Laetoli (Tanzania) and Hadar (Ethiopia). The phylogenetic relationship of these two 'species' is hypothesized as ancestor-descendant. However, the lack of fossil evidence from the time between 3.6 and 3.9 Ma has been one of its weakest points. Recent fieldwork in the Woranso-Mille study area in the Afar region of Ethiopia has yielded fossil hominids dated between 3.6 and 3.8 Ma. These new fossils play a significant role in testing the proposed relationship between Au. anamensis and Au. afarensis. The Woranso-Mille hominids (3.6-3.8 Ma) show a mosaic of primitive, predominantly Au. anamensis-like, and some derived (Au. afarensis-like) dentognathic features. Furthermore, they show that, as currently known, there are no discrete and functionally significant anatomical differences between Au. anamensis and Au. afarensis. Based on the currently available evidence, it appears that there is no compelling evidence to falsify the hypothesis of 'chronospecies pair' or ancestor-descendant relationship between Au. anamensis and Au. afarensis. Most importantly, however, the temporally and morphologically intermediate Woranso-Mille hominids indicate that the species names Au. afarensis and Au. anamensis do not refer to two real species, but rather to earlier and later representatives of a single phyletically evolving lineage. However, if retaining these two names is necessary for communication purposes, the Woranso-Mille hominids are best referred to as Au. anamensis based on new dentognathic evidence.
南方古猿最早的证据可以追溯到 420 万年前，肯尼亚卡纳波伊首次记录到南方古猿“能人”。南方古猿阿法种在 360 万至 300 万年前有很好的记录，主要来自坦桑尼亚的莱托利和埃塞俄比亚的哈达尔的沉积物。这两个“物种”的系统发育关系被假设为祖先-后代。然而，360 万至 390 万年之间缺乏化石证据一直是其最薄弱的环节之一。最近在埃塞俄比亚阿法尔地区沃兰索-米尔研究区的野外工作中发现了一些化石人类，其年代在 360 万至 380 万年之间。这些新化石在检验“能人”和“阿法南方古猿”之间提出的关系方面发挥了重要作用。沃兰索-米尔人类（36-38 万年）表现出原始的镶嵌特征，主要类似于“能人”，还有一些衍生的（类似于“阿法南方古猿”）齿和颌特征。此外，它们表明，就目前所知，“能人”和“阿法南方古猿”之间没有明显的、功能上有意义的解剖差异。根据目前的证据，似乎没有令人信服的证据来否定“能人”和“阿法南方古猿”之间的“时间种对”或祖先-后代关系的假说。然而，最重要的是，沃兰索-米尔人类在时间和形态上处于中间位置，这表明“阿法南方古猿”和“能人”这两个名称并不是指两个真正的物种，而是指一个单一的进化谱系中更早和更晚的代表。然而，如果为了交流目的保留这两个名称是必要的，那么根据新的齿和颌证据，沃兰索-米尔人类最好被称为“能人”。
