Dissertation Research: Phylogenetics of Derived Leptosporangiate Ferns: A Reassessment of the Polypodiaceae S. L.

论文研究：衍生细孢子蕨类植物的系统发育：水龙骨科 S. L. 的重新评估

• 批准号: 0073036
• 负责人: Rudolf Schmid
• 金额: $ 1万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073036&HistoricalAwards=false
• 关键词: Dissertation; Research; Phylogenetics; Derived; Leptosporangiate

0073036Schmid, Smith, and Cranfill Graduate student Raymond Cranfill, under the direction of Drs. Rudolf Schmid and Alan Smith, proposes to study the evolutionary history of derived leptosporangiate ferns, the Polypodiales, through use of both molecular sequence data and morphology. The Polypodiales comprise most of the ferns living today and number about 8,000-10,000 species. They are a conspicuous and diverse element of almost every ecosystem in the wetter tropics and subtropics, as well as some temperate ecosystems. Although we now know that this group is monophyletic (that is, with a single presumed ancestry), our understanding of interrelationships within the Polypodiales is poor and unreliable. This is particularly true for the least specialized or basal groups that were the first to evolve. The evolutionary radiation of the Polypodiales probably occurred over a very short time in the Cretaceous Period, which occurred 140-65 million years ago. Because the diversification apparently was rapid at a relatively distant geological time, we will need to examine several different genes from the chloroplast, mitochondrion, and nucleus, as well as morphological features, in order to define the deeper relationships between these ferns. An understanding of the explicit evolutionary relationships of the Polypodiales is important for several reasons. (1) Because this is the most diverse group of extant ferns, an understanding of these relationships promises to shed light on a range of different and interesting topics in evolutionary and structural biology, from macroevolutionary processes to evolutionarytransformations in morphological characters. (2) A fresh understanding of the latter is particularly important to developmental biologists who are interested in the genetic control of developmental processes in plants. (3) This research is also important to our understanding of the evolution of modern terrestrial and epiphytic (non-terrestrial) ecosystems. It appears that the Polypodialesmay have radiated contemporaneously with the flowering plants and perhaps in response to habitat diversification that occurred as the flowering plants radiated into a wide variety of habitats and began to form communities of greater ecological complexity than may have existed before. Comparable processes appear to be shaping similar patterns of diversity. Therefore, what we learn from ferns may contribute significantly to an understanding of the early evolution and development of plant communities that we see today.

0073036 Schmid，Smith，and Cranfill研究生Raymond Cranfill在Rudolf Schmid和Alan Smith博士的指导下，提出通过使用分子序列数据和形态学来研究衍生的细孢子囊蕨类植物（水龙骨科）的进化历史。水龙骨科包括了现今生活的大多数蕨类植物，约有8，000 - 10，000种。它们是湿润的热带和亚热带以及一些温带生态系统中几乎每一个生态系统的显著和多样的元素。虽然我们现在知道这个类群是单系的（也就是说，有一个假定的祖先），但我们对水龙骨科内相互关系的理解是贫乏和不可靠的。对于最先进化的最不专业或基础群体来说，这一点尤其如此。水龙骨科的演化辐射可能发生在白垩纪的一个很短的时间内，发生在1.4亿至6500万年前。由于在相对遥远的地质时期，这种多样性显然是迅速的，因此我们需要检查叶绿体、叶绿体和细胞核中的几种不同基因以及形态特征，以确定这些蕨类植物之间更深层次的关系。理解水龙骨科明确的进化关系是重要的，原因有几个。(1)因为这是现存蕨类植物中最多样化的一组，对这些关系的理解有望阐明进化和结构生物学中一系列不同的有趣主题，从宏观进化过程到形态特征的进化转化。(2)对于那些对植物发育过程的遗传控制感兴趣的发育生物学家来说，对后者有一个新的认识是特别重要的。(3)这项研究对于我们理解现代陆地和附生（非陆地）生态系统的演变也很重要。看来，Polypodialesmay辐射同期开花植物，也许是为了响应栖息地的多样化，发生了开花植物辐射到各种各样的栖息地，并开始形成社区的生态复杂性比以前可能存在。类似的进程似乎正在形成类似的多样性模式。因此，我们从蕨类植物中学到的东西可能会对我们今天看到的植物群落的早期进化和发展有很大的帮助。