澳大利亚南十字星大学的Renaud Joannes-Boyau团队合作分析了非洲南方古猿牙齿的元素特征，并揭示了其所面临的季节性饮食压力。这一研究成果发表在2019年8月1日出版的国际学术期刊《自然》上。

研究人员使用高分辨率痕量元素分析研究了两个来自Sterkfontein Member (南非)的非洲南方古猿样本，其追溯到2.6-2.1百万年前。元素信号表明非洲南方古猿婴儿在出生后第一年主要食用母乳。与当代野生灵长类动物和其他哺乳动物中观察到的季节性饮食信号相比，在哺乳期后观察到的周期性元素模式表明其不规律的食物供应。这些结果由同位素证据所支持，该地理范围内主要是营养失调的区域。非洲南方古猿牙齿中锂的周期性积累也证实了其变化的范围是由于波动的食物来源导致，并且它们具有对这种不稳定性的生理性适应。这项研究揭示了非洲南方古猿对食物供应的饮食周期和生态行为，这包括面临营养缺乏时母乳摄入的周期性恢复（这也在现代野生猩猩中观察到）。这些牙齿的地球化学发现加强了非洲南方古猿在化石史中的独特地位，并提示这些样本中的饮食压力可以追溯到200万年前南非南方古猿灭绝不久前。

研究人员表示，重建灭绝古人类的具体饮食习惯具有挑战性，特别是对于非洲南方古猿而言，因为其多变的牙齿形貌表明饮食类型广泛。灭绝古人类的饮食如何响应食物供应的季节性波动还知之甚少，看护行为则更甚；目前大多数已知的直接信息来源于对智人（包括现代和化石）、尼安德特人以及现代猿的高分辨率痕量地球化学分析。

附：英文原文

Title: Elemental signatures of Australopithecus africanus teeth reveal seasonal dietary stress

Author: Renaud Joannes-Boyau, Justin W. Adams, Christine Austin, Manish Arora, Ian Moffat

Issue&Volume: Volume 572 Issue 7767

Abstract: Reconstructing the detailed dietary behaviour of extinct hominins is challengingparticularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution trace-element geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis and living apes. Here we apply high-resolution trace-element analysis to two A. africanus specimens from Sterkfontein Member 4 (South Africa), dated to 2.62.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequencecomparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammalsindicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.

DOI: 10.1038/s41586-019-1370-5

Source: https://www.nature.com/articles/s41586-019-1370-5