Testing for non-adaptive radiations in European spring snails

最近，人们对辐射的研究越来越感兴趣。然而，虽然一种形式的辐射自适应辐射已经被广泛研究，但另一种形式的非自适应辐射却被讨论得很有争议且知之甚少。事实上，一些工作者拒绝接受非适应性辐射的概念(即多样化而不是适应于不同的生态位，并导致一组异地物种)。虽然已经为这种辐射提出了具体和可测试的标准，但它们从未以全面和严格的统计方式进行过测试，部分原因是大陆动物群体中的许多辐射(特别是在欧洲)在很大程度上受到人类影响。一个可能的例外是欧洲春季蜗牛属Bysinella；这是一个大型单系类群，具有几个拟议的辐射，分布在整个大陆，但仅受人类影响很小。此外，它假定缺乏形态和生态位分化，使其成为研究非适应性辐射的理想候选者。基于大量的形态、遗传和生态数据，当前项目的目标是识别辐射，测试先前提出的非适应性辐射的标准，并测试适应性和非适应性辐射之间潜在的渐变差异。

Recently, there has been an increased interest in the study of radiations. However, whereas one form of radiation ¿ adaptive radiation ¿ has been studied extensively, another form ¿ non-adaptive radiation ¿ is discussed controversially and poorly understood. In fact, the concept of non-adaptive radiation (i.e., diversification not accompanied by adaptation into various niches and resulting in a group of allopatric species) is rejected by some workers. Although specific and testable criteria have been proposed for this radiation, they have never been tested in a comprehensive and rigorous statistical fashion, partly because many radiations in continental animal groups (particularly in Europe) have been largely affected by human impact. A possible exception is the European spring snail genus Bythinella; a large monophyletic group with several proposed radiations that is distributed throughout the continent, yet only little affected by human impact. Moreover, its presumed lack of morphological and niche differentiation makes it an ideal candidate for studying non-adaptive radiations. Based on extensive morphological, genetic, and ecological data, the goals of the current projects are to identify radiations, to test the previously proposed criteria for nonadaptive radiation and to test for potential gradual differences between adaptive and nonadaptive radiations.