スカンジナビア北部の北極樹の氷河期の生存
Laura Parducci1, Tina Jørgensen, Mari Mette Tollefsrud
1Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
まとめ
コニファール樹は,最後の氷河期中にスカンジナビアで生き残り,氷床が撤退した後に再植民されたという説に異議を唱えました. ノルウェーの湖の堆積物の中に,古代の木のDNAが発見され,氷の無い避難所で生き残ったことを示している.
科学分野:
- パレオボタニーは古植物学です.
- クォーターナリー・パリノロジー
- 分子生態学 分子生態学
背景:
- 支配的な見解では,スカンジナビアは最後の氷河期に樹木がなく,再植民地化は約9000年前に起こったとされています.
- 最後の氷河期におけるスカンジナビアの氷のない避難所は仮説だが,直接的な植物学的な証拠がない.
研究 の 目的:
- 最後の氷河期におけるスカンジナビアの針葉の木の存在と生存を調査する.
- スカンジナビア半島における氷河期後の森林再植民地化の確立されたタイムラインに挑戦するために.
主な方法:
- スプルースの希少なミトコンドリアDNA (mtDNA) ハプロタイプの分析.
- 湖の堆積物と花粉から抽出した古代DNAの放射性炭素年代測定法.
- 塩基板DNAの識別 沈殿体内における松やスプルースのDNAの識別.
主要な成果:
- ノルウェー西部で高い頻度で独特のスカンジナビアスプレース mtDNAハプロタイプを発見.
- トロンデラグ湖の堆積物の中で,このスプルースハプロタイプのDNAが検出され,約10,300年前までさかのぼります.
- ノルウェーの北西部の堆積物における松と杉のDNAの特定は,それぞれ約2万2000年前と1万7700年前,Andøya refugiumの近くまでさかのぼります.
結論:
- 松やスプレースを含むコニファーの木は,スカンジナビアの氷のない避難所の中で最後の氷河期を生き延びました.
- これらの発見は,過去の気候変動への対応として,樹木の生存と分散パターンに関する現在のモデルの見直しを必要としています.
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