REVSYS: Revisionary Systematics of Hawaiian Mecyclothorax Beetles (Coleoptera: Carabidae)

康奈尔大学的詹姆斯·利勃海尔博士获得了一项拨款，用于对夏威夷步甲物种进行分类修改。这一群体表现出极快的物种形成速度；目前的估计表明，近200个物种是从不到200万年前殖民毛伊岛或莫洛凯岛的单一祖先进化而来的，物种形成速度是相关大陆物种的16-40倍。这些物种中有一半以上是未被描述的，其中许多是在过去12年的野外工作中由PI和同事新收集的。对五个以前未被研究过的湿林区进行两次实地考察，将提高该种群物种抽样的地理覆盖率。将对形态特征进行研究，以产生该物种的系统发育假说。分析将包括来自西南太平洋的许多麦环胸鱼物种，从而能够发现夏威夷辐射的来源。这一假说将作为研究推动快速物种形成的进化力量的框架。这些特征还将构成识别关键字的基础--基于网络和印刷出版--使科学家和资源管理人员能够识别单个标本。由于小环胸鱼物种表现出栖息地的特殊性--例如，对特定植物物种、微生境或生命区域的限制--准确的识别将增强在面对不断增加的外来物种引进时监测此类生态状况的能力。PI将比较麦环胸甲虫和独立的夏威夷步甲虫辐射的系统发育模式--黑本尼亚的131个物种--以测试分支生物地理范式的有效性。夏威夷群岛的已知年代在这项测试中提供了强大的时间限制，使夏威夷系统成为进行这项调查的理想地点。系统发育假说还将有助于阐明生态偏好在这种辐射的演化过程中是如何变化的。

A grant has been awarded to Dr. James Liebherr at Cornell University to taxonomically revise Hawaiian carabid beetle species in the genus Mecyclothorax. This group demonstrates extremely rapid speciation; current estimates suggest that the nearly 200 species have evolved from a single ancestor that colonized either Maui or Molokai less than 2 million years ago, a speciation rate 16-40 times more rapid that related mainland species. More than half of these species are undescribed, many having been newly collected by the PI and colleagues during field work over the past 12 years. Two field expeditions to five previously unstudied wet-forest areas will improve geographic coverage for species sampling of the group. Morphological characters will be studied in order to produce a phylogenetic hypothesis of the species. The analysis will include numerous Mecyclothorax species from across the southwest Pacific Ocean, allowing the source for the Hawaiian radiation to be discovered. This hypothesis will serve as the framework within which evolutionary forces driving rapid speciation will be studied. These characters will also form the basis for identification keys-both web-based and print-published-that will enable scientists and resource managers to identify individual specimens.Because Mecyclothorax species exhibit habitat specificity-e.g., restriction to particular plant species, microhabitats, or life zones-accurate identification will enhance the ability to monitor such ecological situations in the face of ever-increasing alien species introductions. The PI will compare phylogenetic patterns in Mecyclothorax with those in an independent Hawaiian carabid beetle radiation-the 131-species of Blackburnia-to test the validity of the cladistic biogeographic paradigm. Known ages of the Hawaiian Islands provide powerful chronological constraints in this test, making the Hawaiian system an ideal venue for carrying out this investigation. The phylogenetic hypothesis will also permit elucidation of how ecological preferences have changed during evolution of this radiation.