Isotopes and red herrings: comments on Milner et al. and Lidén et al.
Isotopes and red herrings: comments on Milner et al. and Lidén et al.
复制标题
同位素和转移注意力：对 Milner 等人和 Lidén 等人的评论。
作者：
R. Hedges
这些评论主要是对米尔纳等人的论文的回应，他们主张对中石器时代-新石器时代过渡时期人骨胶原同位素组成的同位素数据主体进行不太明确的解释，并且，如果根据当前假设应用解释，则对主要饮食来源给出更谨慎的概括。这一论点是由同位素证据和实地挖掘数据估计主要饮食资源之间的差异引起的。然而，除非在同一地点可以获得不同种类的证据，否则很难记录这些差异。例如，在新石器时代的贝壳土丘和/或捕鱼证据非常清楚的地方，几乎没有与海洋饮食资源相冲突的人类同位素数据。此外，人们根本不清楚如何根据幸存的鱼骨或土丘中的贝壳的数量等证据来评估海洋资源（为论证起见，定义为膳食蛋白质的比例）的贡献。此外，米尔纳等人的论点主要基于波罗的海和北海周围的情况，而他们讨论的同位素证据主要来自英国西部的遗址。然而，这些同位素结果可以扩展到包括来自海峡群岛、布列塔尼和法国西海岸的数据，可以说是葡萄牙海岸，事实上，同样的情况也适用于在地中海研究的新石器时代遗址，例如（理查兹等人，2001年; Papathanasiou，2003年）。然而，我的主要目的是反思对来自人骨的同位素证据的解释。米尔纳等人的部分论点是基于人类个体结果太少，无法确定地概括。这只能在非常详细的水平上进行反驳-但事实是，来自欧洲海岸线非常广泛的数十个沿海遗址的数十块新石器时代人类骨骼无一例外地含有陆地价值同位素胶原蛋白。可以相当肯定地说，与公认的陆地值相比，中石器时代的人骨经常显示出富含C的胶原同位素组成，正如米尔纳等人所解释的那样，这可以解释为由于消耗了25%至90%的海洋来源蛋白质--这取决于测量的值，但通常在更高的范围内。相比之下，所有新石器时代的人骨，迄今为止测量，从沿海网站，虽然比较少见，表现出胶原蛋白同位素组成，并没有显着不同，从陆地值。在米尔纳等人的研究中，关于海洋资源丰富的结果没有争议。在非同位素证据的情况下，明显消耗了大量的海洋蛋白质，但没有记录为人类骨胶原中可检测到的δC富集，这一点才是问题的关键。
These comments are primarily in response to the paper by Milner et al. who argue in favour of a far less clear cut interpretation of the body of isotopic data of human bone collagen isotopic composition at the Mesolithic – Neolithic transition, and, if applying the interpretation according to current assumptions, to give more cautious generalisations about the main dietary sources. The argument is driven by perceived discrepancies between estimating the major dietary resource from isotopic evidence and from field excavation data. However, it is difficult to document the discrepancies unless the different kinds of evidence are available in the same place. For example, where Neolithic shell mounds and/or evidence for fishing are very clear, there are virtually no human isotopic data available that conflicts with a marine dietary resource. Furthermore it is not at all clear how one might assess the contribution of marine resources (defined as fraction of dietary protein, for the sake of argument) from such evidence as the quantity of surviving fish bones, or shells in mounds. Moreover, Milner et al’s argument is based most strongly on the situation around the Baltic and North Sea, while the isotopic evidence they discuss is from sites mainly in the western UK. However, those isotopic results could be expanded to include data from the Channel Islands, Brittany and the W coast of France, arguably the coast of Portugal, and in fact the same picture is also applicable to those Neolithic sites studied in the Mediterranean e.g. (Richards et al. 2001; Papathanasiou 2003). My main purpose, however, is to reflect on the interpretation of the isotopic evidence from human bone. Part of the argument of Milner et al is based on there being too few human individual results from which to generalise with certainty. This can only be countered at a very detailed level – but the fact is that scores of human Neolithic bones from dozens of coastal sites over a very wide range of European coastline contain, without exception, terrestrialvalue isotopic collagen. It is quite safe to assert that Mesolithic human bone frequently exhibits collagen isotopic composition enriched in C compared to accepted terrestrial values, which can be interpreted, as explained by Milner et al, as due to the consumption of between 25 and 90 per cent protein – depending on the value measured but often in the higher range – from marine sources. In contrast, all Neolithicperiod human bone so far measured, from coastal sites, although comparatively uncommon, exhibits collagen isotopic composition which does not significantly differ from terrestrial values. There is no dispute in Milner et al concerning results which exhibit high marine resources. The problem really arises for the situation where, on non-isotopic evidence, significant marine protein is apparently consumed, but is not registered as a detectable enrichment of δC in human bone collagen, and it is this point which is the crux of the matter.