顕微鏡で見た、端に化石菌が定着したライニー化石植物の小片。 クレジット: Loron 他
最先端のテクノロジーにより、世界的に有名な化石の宝庫に関する新たな洞察が明らかになり、地球上の初期生命に関する重要な証拠が得られる可能性があります。
スコットランドの北東部の遠隔地で発見された4億年前の化石埋蔵地を調査している科学者らは、その結果、これらの化石における分子の保存レベルが以前の予想より高いことを示したと報告している。
アバディーンシャーの精巧に保存された宝物庫を新たに精査した結果、科学者たちはその中にあるさまざまな生物の化学的指紋を特定することができました。
ロゼッタ ストーンがエジプト学者の象形文字の翻訳に役立ったのと同じように、研究チームは、これらの化学暗号が、他のより曖昧な化石が表す生命体の正体についてさらに解読するのに役立つことを期待しています。
アバディーンシャーのライニー村近くの壮大な化石生態系は 1912 年に発見され、鉱物化され、シリカで構成された硬い岩石であるチャートに包まれていました。 ライニー チャートとして知られるこのチャートは、約 4 億 700 万年前のデボン紀初期に起源を持ち、科学者による地球上の生命の理解において重要な役割を果たしています。
研究者たちは、最新の非破壊イメージングとデータ分析を組み合わせ、[{” attribute=””>machine learning to analyze fossils from collections held by National Museums Scotland and the Universities of Aberdeen and Oxford. Scientists from the University of Edinburgh were able to probe deeper than has previously been possible, which they say could reveal new insights about less well-preserved samples.
Employing a technique known as FTIR spectroscopy – in which infrared light is used to collect high-resolution data – researchers found impressive preservation of molecular information within the cells, tissues, and organisms in the rock.
Since they already knew which organisms most of the fossils represented, the team was able to discover molecular fingerprints that reliably discriminate between fungi, bacteria, and other groups.
These fingerprints were then used to identify some of the more mysterious members of the Rhynie ecosystem, including two specimens of an enigmatic tubular “nematophyte”.
These strange organisms, which are found in Devonian – and later Silurian – sediments have both algal and fungal characteristics and were previously hard to place in either category. The new findings indicate that they were unlikely to have been either lichens or fungi.
Dr. Sean McMahon, Chancellor’s Fellow from the University of Edinburgh’s School of Physics and Astronomy and School of GeoSciences, said: “We have shown how a quick, non-invasive method can be used to discriminate between different lifeforms, and this opens a unique window on the diversity of early life on Earth.”
The team fed their data into a machine learning algorithm that was able to classify the different organisms, providing the potential for sorting other datasets from other fossil-bearing rocks.
The study, published in Nature Communications, was funded by The Royal Society, Wallonia–Brussels International, and the National Council of Science and Technology of Mexico.
Dr Corentin Loron, Royal Society Newton International Fellow from the University of Edinburgh’s School of Physics and Astronomy said the study shows the value of bridging paleontology with physics and chemistry to create new insights into early life.
“Our work highlights the unique scientific importance of some of Scotland’s spectacular natural heritage and provides us with a tool for studying life in trickier, more ambiguous remnants,” Dr. Loron said.
Dr. Nick Fraser, Keeper of Natural Sciences at National Museums Scotland, believes the value of museum collections for understanding our world should never be underestimated.
He said: “The continued development of analytical techniques provides new avenues to explore the past. Our new study provides one more way of peering ever deeper into the fossil record.”
Reference: “Molecular fingerprints resolve affinities of Rhynie chert organic fossils” by C. C. Loron, E. Rodriguez Dzul, P. J. Orr, A. V. Gromov, N. C. Fraser and S. McMahon, 13 March 2023, Nature Communications.
DOI: 10.1038/s41467-023-37047-1