据10月2日的《科学》杂志报道说,科学家们已经发现了由原始植物所产生的琥珀,这些原始植物生活的年代比开花植物出现的年代要早许多,而开花植物是最出名的产生琥珀的来源。
琥珀是树脂所形成的化石,它通常是在应对某种损伤的时候而产生的。 大多数的琥珀是中生代或新生代的产物,其年代可回溯到远至2亿5000年前,它们是由被子植物所产生的。
Sargent Bray及其同僚现在在石炭纪沉积物中发现了琥珀,该时期可回溯到3亿多年以前。 这一时期中的优势植物被称作裸子植物。 令人惊诧的是,这一琥珀与来自被子植物的琥珀具有相似的化学成分,从而提示,产生复杂的琥珀的生物合成机制在出现开花植物之前就已经演化成了。 一则相关的Perspective对这些发现进行了详细的说明。(生物谷bioon.com)
生物谷国庆献礼:新中国生命科学60年
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Science 2 October 2009:DOI: 10.1126/science.1177539
Identification of Carboniferous (320 Million Years Old) Class Ic Amber
P. Sargent Bray* and Ken B. Anderson
The presence of amber, the fossil form of the resins produced by many types of higher plants, has been reported from many localities in Mesozoic and Cenozoic rocks. We have found Class I (polylabdanoid) amber in Carboniferous sediments dating to ~320 million years ago. This result demonstrates that preconifer gymnosperms evolved the biosynthetic mechanisms to produce complex polyterpenoid resins earlier than previously believed and that the biosynthetic pathways leading to the types of polylabdanoid resins that are now typically found in conifers and those now typically found in angiosperms had already diverged by the Carboniferous.
Department of Geology, Southern Illinois University Carbondale, Carbondale, IL 62901, USA.