2023-06-06 ニューサウスウェールズ大学(UNSW)
◆新しい研究によると、最初の花を受粉させた最初の受粉媒介者はおそらく昆虫であったということがわかりました。この研究では、植物の進化の歴史をたどることで、花の多様な家族がどのように受粉されたのかを明らかにしました。
◆その結果、花の進化の過程で昆虫受粉が圧倒的に一般的であり、過去のほぼ86%の花の種は昆虫に依存していたことが分かりました。また、鳥やコウモリなどの脊椎動物による受粉や風による受粉も進化したことが示されています。最初の花を受粉した昆虫は正確には分かっていませんが、非常に小型の昆虫や昔から絶滅してしまった昆虫の可能性があります。
<関連情報>
- https://newsroom.unsw.edu.au/news/science-tech/world%E2%80%99s-first-flowers-were-pollinated-insects
- https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18993
被子植物の進化史の大半を昆虫受粉が占める Insect pollination for most of angiosperm evolutionary history
Ruby E. Stephens, Rachael V. Gallagher, Lily Dun, Will Cornwell, Hervé Sauquet
New Phytologist Published: 05 June 2023
DOI:https://doi.org/10.1111/nph.18993
Summary
- Most contemporary angiosperms (flowering plants) are insect pollinated, but pollination by wind, water or vertebrates occurs in many lineages. Though evidence suggests insect pollination may be ancestral in angiosperms, this is yet to be assessed across the full phylogeny. Here, we reconstruct the ancestral pollination mode of angiosperms and quantify the timing and environmental associations of pollination shifts.
- We use a robust, dated phylogeny and species-level sampling across all angiosperm families to model the evolution of pollination modes. Data on the pollination system or syndrome of 1160 species were collated from the primary literature.
- Angiosperms were ancestrally insect pollinated, and insects have pollinated angiosperms for c. 86% of angiosperm evolutionary history. Wind pollination evolved at least 42 times, with few reversals to animal pollination. Transitions between insect and vertebrate pollination were more frequent: vertebrate pollination evolved at least 39 times from an insect-pollinated ancestor with at least 26 reversals. The probability of wind pollination increases with habitat openness (measured by Leaf Area Index) and distance from the equator.
- Our reconstruction gives a clear overview of pollination macroevolution across angiosperms, highlighting the long history of interactions between insect pollinators and angiosperms still vital to biodiversity today.
