Competitive Displacement: The Role of Reproductive Mode and Parasitism

一个大范围的生物地理模式表明，家壁虎，半爪虎，在被引入整个太平洋岛屿后，至少取代了其他三个物种。这一轨迹至少在三个群岛上得到了复制：瓦努阿图、夏威夷和斐济。被转移的物种中有两种是无性孤雌原虫：加尔蒂尼半爪龙和羽翼龙。这项研究将确定造成这种置换的生态机制和繁殖模式所起的作用。潜在的机制分为两类：竞争和“明显的竞争”。在竞争的标题下，该项目将结合操纵性田间实验和圈养实验来检验关于剥削和干扰竞争的假说。在“表观竞争”类别中，将通过筛选每个物种的肠道、肺部和血液寄生虫来检查寄生虫在群落动态中的潜在作用。沿着同样的路线，无性物种的克隆多样性将在斐济和太平洋彼岸，通过一种被称为混合淋巴细胞反应(MLR)的免疫学技术来实现。不同无性系的分布范围将被绘制出来，并与寄生虫负担的克隆差异相关联。将维持有性繁殖归因于生态原因的几个模型，关键取决于无性物种中具有生态意义的克隆的数量。

A wide-scale biogeographic pattern shows that a house gecko, Hemidactylus frenatus, upon introduction to islands throughout the Pacific, replaces at least three other species. This trajectory has been replicated in at least three archipelagoes: Vanuatu, Hawaii and Fiji. Two of the species that are displaced are asexual parthenogens: Hemidactylus garnotii and Lepidodactylus lugubris. This research will determine the ecological mechanism responsible for the displacement and the role played by the mode of reproduction. Potential mechanisms fall into two categories: competition and "apparent competition". Under the heading of competition, the project will examine hypotheses concerning exploitation and interference competition with a combination of manipulative field experiments and captive experiments. In the "apparent competition" category, the potential role of parasites in the community dynamics will be examined by screening each species for gut, lung and blood parasites. Along those same lines, the clonal diversity of the asexual species will be both in Fiji and across the Pacific, with an immunological technique known as the mixed lymphocyte reaction (MLR). Distributional ranges of different clones will be mapped and associated with clonal differences in parasite burdens. Several models attributing ecological reasons for the maintenance of sexual reproduction hinge critically on the number of ecologically significant clones in the asexual species.