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Nephrotic Syndrome I : Introduction
Published on: June 19, 2025
476
陆地植物根的逐步和独立的起源
Alexander J Hetherington1, Liam Dolan2
1Department of Plant Sciences, University of Oxford, Oxford, UK.
Nature
|August 24, 2018
概括
化石发现显示,古代植物根缺乏保护性根盖,这表明根逐渐演变出像帽子这样的复杂特征. 这一发现支持了多个根源进化起源的理论,而不是单一事件.
科学领域:
- 古植物学
- 进化生物学
- 植物解剖学
背景情况:
- 根是重要的血管植物器官,用于定和吸收营养/水.
- 根盖的进化起源,是现代根的定义特征,由于化石记录的局限性,仍然不清楚.
研究的目的:
- 调查血管植物中根髓和根盖的早期演变.
- 为了分析古老的虫Asteroxylon mackiei的生根器官的形态.
主要方法:
- 检查了4亿7千万年前的莱尼尼河的化石.
- 在Asteroxylon mackiei化石中微观分析体结构.
主要成果:
- 在Asteroxylon mackiei发现已知最古老的根干,可以追溯到4亿7千万年前.
- 这些古老的树根没有根盖,而是连续的表皮.
- 在已知的血管植物中,A. mackiei的植根器官是独一无二的.
结论:
- 在早期的白植物根中缺少根盖,支持根特征的逐步演变.
- 这一发现与根源多次独立进化 (融合进化) 的假设一致.
- 在植物进化过程中,Asteroxylon mackiei的过渡性植根器官提供了关于植根"组装"过程的见解.
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