世界最古、４万５５００年以上前の洞窟壁画　インドネシア洞窟で発見

【ワシントンＡＦＰ＝時事】インドネシア・スラウェシ島の洞窟で少なくとも4万5500年前に描かれた等身大のイノシシの壁画が見つかり、これまで発見された中では世界最古の洞窟壁画だとする研究結果が13日、米科学誌サイエンス・アドバンシスに発表された。この地域に人類が定住していたことを示す最も古い証拠だ。（写真はインドネシア・スラウェシ島の洞窟で見つかった、4万5500年以上前に描かれた等身大のイノシシの壁画）
　論文を共同執筆した豪グリフィス大学の研究者マキシム・オーバート氏がＡＦＰに語ったところによると、この洞窟壁画は２０１７年、同大研究チームがインドネシア当局と共同で行った調査で、博士課程の学生バスラン・ブルハン氏が発見した。
　洞窟は、最も近い道路からでも徒歩で約１時間かかる人里離れた谷間にある。切り立った石灰岩の断崖に囲まれていて、乾期にしか行けない。現地の孤立先住民ブギスの人々によると、これまで欧米人が目にしたことはなかった。
　縦５４センチ、横１３６センチのイノシシの絵は暗い赤色の土性顔料を用いて描かれ、短い毛が逆立ったたてがみや、スラウェシ島固有種のイノシシの成体の雄に特徴的な顔から角のように生えた一対のいぼが確認できる。臀部（でんぶ）の近くには、２つの手形が押されている。
　このイノシシと向かい合うような位置には、部分的にしか残っていない別の２匹のイノシシの壁画もあり、論文共著者のアダム・ブラム氏は「２匹の闘いか交流を、もう１匹が観察しているように見える」と述べている。
　スラウェシ島では人類が数万年前からイノシシの狩猟を行っていたことが分かっており、狩猟の様子は先史時代の洞窟壁画の主な特徴となっている。
　オーバート氏は、壁画の上に付着した方解石堆積物の放射年代測定を行い、４万５５００年前のものだと突き止めた。これにより、壁画が４万５５００年以上前に描かれたことは確かだとしている。
　これまで確認されていた世界最古の洞窟壁画は、少なくとも４万３９００年前に描かれた狩人と動物の壁画で、同じグリフィス大の研究チームがスラウェシ島で発見したものだった。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2021/01/14-12:21）

Archaeologists have discovered the world's oldest known cave painting: a life-sized picture of a wild pig that was made at least 45,500 years ago in Indonesia.
The finding described in the journal Science Advances on Wednesday provides the earliest evidence of human settlement of the region.
Co-author Maxime Aubert of Australia's Griffith University told AFP it was found on the island of Sulawesi in 2017 by doctoral student Basran Burhan, as part of surveys the team was carrying out with Indonesian authorities.
The Leang Tedongnge cave is located in a remote valley enclosed by sheer limestone cliffs, about an hour's walk from the nearest road.
It is only accessible during the dry season because of flooding during the wet season -- and members of the isolated Bugis community told the team it had never before been seen by Westerners.
Measuring 136 by 54 centimeters (53 by 21 inches) the Sulawesi warty pig was painted using dark red ochre pigment and has a short crest of upright hair, as well as a pair of horn-like facial warts characteristic of adult males of the species.
There are two hand prints above the pig's hindquarters, and it appears to be facing two other pigs that are only partially preserved, as part of a narrative scene.
The pig appears to be observing a fight or social interaction between two other warty pigs, said co-author Adam Brumm.
Humans have hunted Sulawesi warty pigs for tens of thousands of years, and they are a key feature of the region's prehistoric artwork, particularly during the Ice Age.
- Early human migration -
Aubert, a dating specialist, identified a calcite deposit that had formed on top of the painting, then used Uranium-series isotope dating to confidently say the deposit was 45,500 years old.
This makes the painting at least that age, but it could be much older because the dating that we're using only dates the calcite on top of it, he explained.
The people who made it were fully modern, they were just like us, they had all of the capacity and the tools to do any painting that they liked, he added.
The previously oldest dated rock art painting was found by the same team in Sulawesi. It depicted a group of part-human, part-animal figures hunting mammals, and was found to be at least 43,900 years old.
Cave paintings such as these also help fill in gaps about our understanding of early human migrations.
It's known that people reached Australia 65,000 years ago, but they would probably have had to cross the islands of Indonesia, known as Wallacea.
This site now represents the oldest evidence of humans in Wallacea, but it's hoped further research will help show people were in the region much earlier, which would resolve the Australia settlement puzzle.
The team believes the artwork was made by Homo sapiens, as opposed to now extinct human species like Denisovans, but cannot say this for certain.
To make handprints, the artists would have had to place their hands on a surface then spit pigment over it, and the team are hoping to try to extract DNA samples from residual saliva.