Character evolution in pleurocarpous mosses: a phylogenetic study focusing on the Lembophyllaceae/Neckeraceae - clade

附生侧果苔藓的形态多样性及其近期的快速辐射是苔藓学中最具挑战性的问题之一。由于目前关于性状进化的概念在很大程度上具有误导性，需要结合分子和形态数据进行彻底的系统发育分析，这对于理解侧果苔藓的进化至关重要。在这项研究中，我们将集中在两个密切相关的科，莲科和莲科。这项研究的目的是：1)利用形态和DNA序列数据重建这些科的系统发育；2)确定锦鸡科/香茅科的祖先支系；3)研究该类群内形态特征的进化。系统发育分析将包括最新的方法，如最大似然法、贝叶斯推理以及基于简约的方法。系统发育分析将a)在DNA/RNA二级结构计算和分子模式分析的指导下，对人工比对的序列数据进行，以及b)应用直接优化-基于简约的新算法。这些深入的分析将为鲤鱼分子进化的模式和速度提供新的见解，提出一个新的研究小组的系统发育概念，并鉴定形态突触。我们将阐明目前使用的诊断性形态性状的进化是否是独立适应性进化的结果，特别是对附生生境的进化，这种进化在样本谱系中独立发生了几次，也许在通常的丰果苔藓中也是如此。

The morphological diversity of epiphytic pleurocarpous mosses and their recent rapid radiation is one of the most challenging problems in bryology. As current concepts of character evolution are largely misleading, thorough phylogenetic analyses combining molecular and morphological data are needed and crucial for understanding the evolution of pleurocarpous mosses. In this study we will focus on two closely related families, Lembophyllaceae and Neckeraceae. Aims of this study are: 1) to reconstruct well supported phylogenies of the families using both morphological and DNA sequence data 2) to pinpoint the ancestral clades of the Neckeraceae/Lembophyllaceae within pleurocarps, and 3) to study the evolution of morphological characters within this group. The phylogenetic analyses will comprise state of the art approaches such as maximum likelihood, Bayesian inference as well as parsimony-based methods. Phylogenetic analyses will be performed a) on manually aligned sequence data, guided by DNA/RNA secondary structure calculations and analyses of molecular patterns, and b) applying direct optimization a novel parsimony-based algorithm. The thorough analyses will provide new insights into the modes and rates of molecular evolution in pleurocarps, present a new phylogenetic concept of the study group and identify morphological synapomorphies. We will clarify if the evolution of the currently used diagnostic morphological traits is a result of an independent adaptive evolution, especially to epiphytic habitats that occurred several times independently in the sampled lineages and perhaps in pleuocarpous mosses in general.