人類の争いはいつから始まったか？

今週のNatureで発表された研究。定住していない狩猟採集民同士でも争いがあったことを示す人骨がケニアで見つかったようです。動画に出ている研究者はアルゼンチン生まれのようで若干なまりのある英語を話されています。このような従来の定説を覆すような発見は英検の好物でもありますね（笑）

Inter-group violence among early Holocene hunter-gatherers of West Turkana, Kenya
Nature 529, 394–398 (21 January 2016) doi:10.1038/nature16477
Received 31 July 2015 Accepted 23 November 2015 Published online 20 January 2016
The nature of inter-group relations among prehistoric hunter-gatherers remains disputed, with arguments in favour and against the existence of warfare before the development of sedentary societies1, 2. Here we report on a case of inter-group violence towards a group of hunter-gatherers from Nataruk, west of Lake Turkana, which during the late Pleistocene/early Holocene period extended about 30 km beyond its present-day shore3. Ten of the twelve articulated skeletons found at Nataruk show evidence of having died violently at the edge of a lagoon, into which some of the bodies fell. The remains from Nataruk are unique, preserved by the particular conditions of the lagoon with no evidence of deliberate burial. They offer a rare glimpse into the life and death of past foraging people, and evidence that warfare was part of the repertoire of inter-group relations among prehistoric hunter-gatherers.

残念ながらNatureの研究は無料では読めません。その代わりというか研究を発表した大学の方で丁寧な紹介記事をサイトで発表していました。人類最古の争いの証拠とあってか冒頭の動画も作成したりして広報に力をいれているようですね。ただ、こちらのサイトの説明は研究者向けなのかお堅い調子なので次に紹介するものを読んだ方が読みやすいと思います。

Evidence of a prehistoric massacre extends the history of warfare
Skeletal remains of a group of foragers massacred around 10,000 years ago on the shores of a lagoon is unique evidence of a violent encounter between clashing groups of ancient hunter-gatherers, and suggests the “presence of warfare” in late Stone Age foraging societies.

以下の方が専門的な記述が少ないので読みやすくなっています。研究者のMarta Mirazon Lahrさんが研究の意義などを説明してくださっています。they challenge our understanding of the roots of conflict（これらの発見は紛争の起源についての我々の理解に異議を唱えるものである）と動詞challengeが使われていることは英語学習者的には注目です。

Finding a hunter-gatherer massacre scene that may change history of human warfare
January 21, 2016 5.02am AEDT
Marta Mirazon Lahr

The area surrounding Lake Turkana in Kenya was lush and fertile 10,000 years ago, with thousands of animals – including elephants, giraffes and zebras – roaming around alongside groups of hunter gatherers. But it also had a dark side. We have discovered the oldest known case of violence between two groups of hunter gatherers took place there, with ten excavated skeletons showing evidence of having been killed with both sharp and blunt weapons.
The findings, published in Nature, are important because they challenge our understanding of the roots of conflict and suggest warfare may have a much older history than many researchers believe.

書き出し部分のところをもう少し詳しく展開してくれているのが以下の部分です。

We dated the remains and the site to between 10,500 and 9,500 years ago, making them the earliest scientifically dated case of a conflict between two groups of hunter-gatherers. Stones in the weapons include obsidian, a rare stone in the Nataruk area, suggesting the attackers came from a different place.

The (pre)history of warfare
Today we think of warfare, or inter-group conflict, as something that happens when one group of people wants the territory, resources or power held by another. But prehistoric societies were usually small groups of nomads moving from place to place – meaning they didn’t own land or have significant possessions. They typically didn’t have strong social hierarchies either. Therefore, many scholars have argued that warfare must have emerged after farming and more complex political systems arose.

Man with an obsidian bladelet embedded into the left side of his skull, and a projectile lesion (possibly of a sharpened arrow shaft) on the right side of the skull. Marta Mirazon Lahr
Naturuk therefore challenges our views about what the causes of conflict are. It is possible that human prehistoric societies simply responded antagonistically to chance encounters with another group. But this is not what seems to have happened at Nataruk. The group which attacked was carrying weapons that would not normally be carried while hunting and fishing. In addition, the lesions show that clubs of at least two sizes were used, making it likely that more than one of the attackers were carrying them.

土地や資源は定住者だけでなく狩猟採集民にとっても重要なものだったのではないかと紛争の原因を推測しています。

So why were the people of Nataruk attacked? We have to conclude that they had valuable resources that were worth fighting for – water, meat, fish, nuts, or indeed women and children. This suggests that two of the conditions associated with warfare among settled societies – territory and resources – were probably common among these hunter-gatherers, and that we have underestimated their role so far.

若干とってつけたような終わり方ですが、何も狩猟採集民が争い好きだと結論づけたかったわけではないようで、他人を思いやることもあっただろうとしています。

Evolution is about survival, and our species is no different from others in this respect. The injuries suffered by the people of Nataruk are merciless and shocking, but no different from those suffered in wars throughout much of our history – sadly even today. It may be human nature, but we should not forget that extraordinary acts of altruism, compassion and caring are also unique parts of who we are.

狩猟採集民を牧歌的に捉えたくなりますが、まあ人類は昔から大して変わっていないかもしれないのですね。