アマゾンでは1万年前には農耕が行われていた―らしい

　アマゾン地域には、なにやら洪水時にも水面上に出る「森の島」があるんだそうだ。4700個ほどもあるのだとか。まるで水田地帯のなかの円墳のようだが、これは純粋に自然な存在ではなく、人間活動の堆積物を基礎としつつ形成されたものらしく、こうした「森の島」を調査すると―

BBC Crops were cultivated in regions of the Amazon '10,000 years ago' 8 Apr 2020 By Matt McGrath

　―例のシリカのビーズ、phytolithが発見される。この年代を調べると、キャッサバやトウモロコシや…がすでに10000年前ころから栽培されていたらしいことが分かるのだという。

「Far from being a pristine wilderness, some regions of the Amazon have been profoundly altered by humans dating back 10,000 years, say researchers.

An international team found that during this period, crops were being cultivated in a remote location in what is now northern Bolivia.

The scientists believe that the humans who lived here were planting squash, cassava and maize.

The inhabitants also created thousands of artificial islands in the forest.」

　四大文明などというが、その前段階、中華地方の米、中東の小麦、中央アメリカ・メキシコのトウモロコシのほか、アマゾン地域（いまのボリビアあたり）でも農耕が行われていたとは、これは大発見というべきだ。

「Perhaps the most important of these was that early civilisations began to move away from living as hunter-gatherers and started to cultivate crops for food.

Researchers have previously unearthed evidence that crops were domesticated at four important locations around the world.

So China saw the cultivation of rice, while in the Middle East it was grains, in Central America and Mexico it was maize, while potatoes and quinoa emerged in the Andes.

Now scientists say that the Llanos de Moxos region of southwestern Amazonia should be seen as a fifth key region.

The area is a savannah but is dotted with raised areas of land now covered with trees.」

「The area floods for part of the year but these "forest islands" remain above the waters.

Some 4,700 of these small mounds were developed by humans over time, in a very mundane way.」

　4700個の島々のうち、30個について調査したものとのこと。

「The researchers examined some 30 of these islands for evidence of crop planting.

They discovered tiny fragments of silica called phytoliths, described as tiny pieces of glass that form inside the cells of plants.」

　キャッサバの類が10350年前、かぼちゃの類が10250年前、トウモロコシが6850年前。アマゾン地域はついこのあいだ文明化された手つかずの大地だとわりとそう思いがちだが、すでに知られた諸文明以前の初期農耕、それも最古級のそれがなされていた―そしてそのこと自体が地形を構成・改変していた―という、大変興味深いお話。

「The researchers were able to identify evidence of manioc (cassava, yuca) that were grown 10,350 years ago. Squash appears 10,250 years ago, and maize more recently - just 6,850 years ago.」

「"This is Amazonia, this is one of these places that a few years ago we thought to be like a virgin forest, an untouched environment."

"Now we're finding this evidence that people were living there 10,500 years ago, and they started practising cultivation."」

　純粋にすごいな。
　こんな分野の研究してたら、もう面白くてたまらんだろう。
　…私もまあなあ、いまやっているのは、世間的には受けがよいだろうが…時間の取れない職業の、この合間に面白くパズルで楽しめるという条件で選んだテーマではあるしなあ…。