Phylogeny and Evolution of Caesalpinioid Legumes

豆科植物（或Fabaceae-豆科或豆类）是开花植物的第三大家族，也是经济上第二重要的家族。 豆科植物的范围从巨大的雨林树木到沙漠栖息地的小型草本一年生植物。 在传统上公认的三个亚科中，Caesalpinioideae，Mimosoideae和Papilionoideae，Caesalpinioideae是最鲜为人知的，因为它主要局限于热带栖息地。因此，caesalpinioid豆科植物之间的进化关系知之甚少，特定属的识别往往存在争议。 Herendall博士和他在加拿大和英国的同事以前的工作已经为Caesalpinioideae建立了一个一般的系统发育框架，这将用于进一步研究形态学，分类学和系统发育。 目前的形态学和分子生物学数据表明，几个caesalpinioid谱系有更多的基础位置比含羞草亚科或蝶亚科。 因此，一个基于进化关系的科分类系统不会将苏木类视为一个单一的自然单位，而是作为几个早期分支的谱系。 有多少种不同的云实豆科植物谱系，相对于含羞草和蝶形花科植物，它们应该在什么水平上被识别，云实属之间的关系是什么，我们能辨别出什么样的形态进化模式？ 这些问题构成了研究的核心。这项研究的主要目标是产生一个分类，包括所有的CA。根据形态学和DNA序列数据分析，将160个属划分为云实科豆科植物。 为了实现这一目标，将在马达加斯加、南美洲和东南亚进行实地考察，以获得尽可能多的缺失属的材料。 调查人员还将研究标本馆的收藏品，并准备解剖样本，对分子数据集中包括的所有物种的形态特征进行评分。 他们将使用系统发育的结果，以产生一个修订的分类和识别关键的亚科，族，属的所有caesalpinioid豆类。有了一个强大的基因组和一个基于基因组的形态数据集，他们将能够探索基因组与形态进化模式的影响。 此外，各种豆类化石的数据将与结果相结合。这些化石可以用来记录分支的最小年龄，也可以作为地理学研究的历史数据点。 此外，分子钟技术将被用来估计年龄的分支。 在这项研究中产生的数据将使Legumatum一个理想的群体，在其中实验的新方法估计年龄的分支和评估率的分类多样化和分子进化。

The Leguminosae (or Fabaceae - the legume or bean family) is the third largest family of flowering plants, and the second most important family economically. Legumes range from giant rain forest trees to tiny herbaceous annuals of desert habitats. Of the three traditionally recognized subfamilies, Caesalpinioideae, Mimosoideae, and Papilionoideae, the Caesalpinioideae is the most poorly known because it is largely confined to tropical habitats. As a consequence, evolutionary relationships among caesalpinioid legumes are poorly known and the recognition of particular genera is often in dispute. Previous work by Dr. Herendeen and his colleagues in Canada and England has developed a general phylogenetic framework for Caesalpinioideae, which will be used to further research on morphology, taxonomy, and phylogeny. Current morphological and molecular data show that several caesalpinioid lineages have more basal positions than either the Mimosoideae or Papilionoideae. Thus a classification system for the family based on evolutionary relationships would not recognize the caesalpinioids as a single natural unit but as several early-branching lineages. How many distinct lineages of caesalpinioid legumes are there, at what level should they be recognized relative to mimosoids and papilionoids, what are the relationships among caesalpinioid genera, and what can we discern about patterns of morphological evolution? These questions form the core of the study. The primary goal of this research is to produce a classification that includes all ca. 160 genera of caesalpinioid legumes based on analyses of data from morphology and DNA sequence data. To achieve this, field work will be conducted in Madagascar, South America, and SE Asia to obtain material of as many of the missing genera as possible. The investigators will also study collections in herbaria and prepare anatomical samples to score morphological characters for all species included in the molecular data set. They will use the phylogenetic results to produce a revised classification and identification key to subfamilies, tribes, and genera for all caesalpinioid legumes. With a robust phylogeny and a specimen-based morphological data set, they will be able to explore the implications of the phylogeny with respect to patterns of morphological evolution. In addition, data on a diverse array of fossil legumes will be integrated with the results. The fossils may be used in documenting minimum ages of clades and as historical data points for biogeographic studies. In addition, molecular clock techniques will be used to estimate ages of clades. The data generated in this study will make the Leguminosae an ideal group in which to experiment with new methods in estimating ages of clades and assessing rates of taxonomic diversification and molecular evolution.