Phylogenetic Relationships and Skeletomuscular Evolution of the Arachnids

节肢动物（蜘蛛、螃蟹、昆虫及其近亲）有着漫长而复杂的历史（系统发育），是所有动物类群中形状和形态多样性最大的。为了更好地理解这些复杂的、通常在经济上很重要的动物是如何工作的，了解它们是如何组合在一起的是很重要的；尤其重要的是要知道肌肉是如何附着在每种动物坚硬的外表面（外骨骼）上，形成骨骼肌肉复合物，使动物能够移动、进食和繁殖。某些骨骼肌复合体在节肢动物的历史中可能只出现过一次；另一些看起来相似，功能相似的，可能出现在节肢动物系统发育树上的几个不同的地方。然而，由于尚未获得足够的信息来确定节肢动物群体的真正系统发育，目前很难评估特定的骨骼肌复合物在节肢动物历史中是否出现过一次或不止一次。在这项研究中，杰弗里·w·舒尔茨将研究节肢动物中一个主要群体——蛛形纲动物（蜘蛛、蝎子、螨虫和它们的亲戚）——骨骼肌肉复杂结构的细节。他将使用骨骼肌特征，无论是单独的还是结合分子序列数据，来重建蛛形纲动物的系统发育，然后使用系统发育来估计特定的骨骼肌复合物在蛛形纲动物中出现的时间、方式和频率，以及这些复合物在这些动物的整个历史中在形式和功能上是如何变化的。预计这一分析将解决长期存在的一个重要节肢动物类群的系统发育和进化形态学问题。

9615526 SHULTZ Arthropods (spiders, crabs, insects and their relatives) have a long and complex history (phylogeny), and the greatest diversity in shape and form of all the animal groups. In order to better understand how these complex, and often economically important, animals actually work, it is important to know how they are put together; it is especially important to know how muscles are attached to the hardened outer surface (exoskeleton) of each animal, forming Oskeletomuscular complexesO that permit the animals to move, feed, and reproduce. Certain skeletomuscular complexes may have occurred only once in the histories of arthropods; others, which may look alike and function in a similar way, may have appeared in several different places in the arthropod phylogenetic tree. However, since not enough information has yet been obtained to determine the true phylogeny of arthropod groups, it is, at present, difficult to assess whether particular skeletomuscular complexes appeared once or more than once in arthropod history. In this study, Jeffrey W. Schultz will examine the details of skeletomuscular complex structures in a major group of arthropods, the arachnids (spiders, scorpions, mites and their relatives). He will use skeletomuscular characters, both alone and with molecular sequence data, to reconstruct the phylogeny of the arachnids, and will then use the phylogeny to estimate when, how, and how often particular skeletomuscular complexes appeared in arachnids, and how these complexes changed, in form and function, throughout the history of these animals. It is expected that this analysis will solve long-standing problems in the phylogeny and evolutionary morphology of an important group of arthropods.