Radiation in sexual and parthenogenetic oribatid mites (Acari, Acariformes)

甲螨（阿卡里：蜱螨目）是最丰富和多样的陆生节肢动物之一。几个甲螨群可能辐射，尽管他们完全单性生殖模式（如Nanhermanniidae，Camisidae，Trhypochthonidae，Nothridae，Malaconothridae），并存活了很长一段时间。这两个发现都与性的进化和维持理论相矛盾。单性生殖谱系被认为是短命的和进化的死胡同。为了研究甲螨的辐射和多样性，我们打算调查三个主题：（1）我们打算评估是否有性类群比无性类群辐射快。因此，我们正在比较的遗传多样性（COI和HSP 82区）密切相关的无性类群与密切相关的性群体之间。(2)我们想利用延伸因子-1-aa来评估无气门目甲螨的系统发育位置。无气门（阿卡里：蜱螨目（Acariformes）是一个完全有性的类群，最近被假设是一个完全单性生殖的甲螨类群Trhypochthonidae的姐妹类群。如果这是真的，无气门纲是动物王国中唯一一个重新进化有性生殖，然后强烈辐射的分类单元（大约有10000种无气门纲被描述）。(3)我们要调查的假设，土壤中的通才捕食者减少土壤节肢动物（如甲螨）之间的生物相互作用，使大量的物种共存。此外，利用稳定同位素技术（15-N，13-C）甲螨的营养位置进行评估，以找出这些动物栖息在不同的营养位置在土壤食物网，从而表明营养生态位分化。

Oribatid mites (Acari: Acariformes) are among the most abundant and diverse terrestrial arthropods. Several oribatid mite groups probably radiated despite their exclusively parthenogenetic mode of reproduction (e.g. Nanhermanniidae, Camisidae, Trhypochthonidae, Nothridae, Malaconothridae) and survived long periods of time. Both findings contradict theories on the evolution and maintenance of sex. Parthenogenetic lineages are assumed to be short lived and evolutionary dead ends. To investigate the radiation and diversity of oribatid mites we intend to investigate three topics: (1) We intend to evaluate whether sexual taxa radiated faster than asexual taxa. We are therefore comparing the genetic diversity (COI and HSP82 region) between closely related asexual taxa with that of closely related sexual groups. (2) We want to evaluate the phylogenetic position of the Astigmata within the oribatid mites using the elongation factor-1-aa. The Astigmata (Acari: Acariformes) are an entirely sexual group which has recently been hypothesised to be the sister group of an entirely parthenogenetic group of oribatid mites, the Trhypochthonidae. If this is true, the Astigmata are the only taxon in the animal kingdom that re-evolved sexual reproduction and then intensively radiated (about 10000 species of Astigmata are described). (3) We want to investigate the hypothesis that generalist predators in soil reduce biotic interactions between soil arthropods (e.g. oribatid mites) and enable the coexistence of a large number of species. Furthermore, using stable isotope techniques (15-N, 13-C) the trophic position of oribatid mites is evaluated to find out if these animals inhabit different trophic positions in the soil food web thereby indicating trophic niche differentiation.