Do molecules bear the key to solving a complex taxonomic problem? The Western Palearctic jewel leaf beetles in the genus Cryptocephalus Müller (Coleoptera, Chrysomelidae)

使用分子来解决分类问题(例如，DNA分类学、DNA条形码)如今被认为是回答地球上有多少物种这一问题的最有前途的方法。这一策略是作为由专家驱动的基于形态的传统分类法的替代方案提出的，旨在克服后一种方法的一些局限性。然而，这种基于DNA的还原方法论提出了其他同样令人担忧的问题，在处理最近形成的和/或没有发展出强大的隔离机制的生物群时，这些问题变得更加明显，如物种复合体。遗传变异的不完全谱系分类或基因流介导的导入可能导致错误的生物多样性评估。欧洲隐头虫(鞘翅目，叶甲科)是一个物种复合体，可以用这些替代方法来研究关于物种多样性的答案的一致性。基于成虫形态和雄性生殖器的分析，物种假说有一个坚实的框架，提出了20个分类单元。然而，也有证据表明，在两个或更多分类群重叠的地理区域(例如阿尔卑斯山)，中间形式的谱系是不完全隔离的。在这项建议中，我们计划分别使用系统发育和系统地理学方法(后者作为初步研究)来研究Sericeus复合体和一个隶属的复合体--C.subchaeridis复合体。在这两种情况下，将使用两个独立的遗传标记(mtDNA细胞色素氧化酶1和核rRNA内转录间隔区2)，根据之前对类似生物的研究，我们预计它们之间以及与形态的不一致，每个分类标记显示不同的地理模式。这些结果将被用来提供关于这些物种复合体的多样化模式和导致该集团目前的物种多样性的基本过程的信息。它们还将被用来警告使用单标记方法进行分类推断(DNA条形码)。

The use of molecules to address taxonomic questions (e.g., DNA taxonomy, DNA barcoding) is perceived nowadays as the most promising approach to answer the question of how many species there are on the planet. The strategy is presented as alternative to traditional morphology-based taxonomy driven by specialists and intends to overcome some of the limitations of the latter approach. However, such a reductionist DNA-based methodology poses other equally worrying problems which become more apparent when dealing with groups of organisms which have speciated recently and/or have not developed strong isolation mechanisms, as species complexes. Incomplete lineage sorting of genetic variants or gene-flow mediated introgression can lead to erroneous biodiversity assessment. The European Cryptocephalus sericeus (Coleoptera, Chrysomelidae) is a species complex amenable to study the congruence of answers about species diversity using these alternative approaches. There is a solid framework for species hypotheses based on the analysis of adult morphology and male genitalia, proposing 20 taxa. However, there is also evidence pointing towards incomplete isolation of lineages with intermediate forms in geographical areas of overlap of two or more taxa (e.g., the Alps). In this proposal we plan to study the C. sericeus complex and a subordinated complex, the C. hypochaeridis complex, using phylogenetic and phylogeographic methods, respectively (the latter as a pilot study). In both cases, two independent genetic markers (mtDNA cytochrome oxidase 1 and nuclear rRNA internal transcribed spacer 2) will be used and, based on previous studies on similar organisms, we expect incongruence among them and with morphology, each taxonomic marker showing different geographical patterns. These results will be used to provide information about both the patterns of diversification in these species complexes and the underlying processes leading to the current species diversity in the group. They will also be used to caution about the use of single marker approaches for taxonomic inference (DNA barcoding).