Testing allopatric and ecological speciation in a morphologically and genetically diverse species flock of viviparous freshwater gastropods (Mollusca: Cerithioidea: Pachychilidae) in the ancient lakes of Sulawesi, Indonesia

在印度尼西亚苏拉威西岛古湖泊中测试形态和遗传多样化的胎生淡水腹足动物（软体动物：Cerithioidea：Pachychilidae）物种群的异域和生态物种形成

• 批准号: 5362516
• 负责人: Professor Dr. Matthias Glaubrecht
• 金额: --
• 依托单位: Standort Hamburg
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5362516?language=en
• 关键词: Testing; allopatric; ecological; speciation; morphologically

Speciation in the context of a radiation is regarded as a key process in the creation of organismic diversity. Adaptive radiations in lakes provide almost perfect conditions to study the ecology of speciation, with freshwater gastropods being ideal model organisms. The ancient Malili lakes on Sulawesi, Indonesia, harbour an endemic species flock of about 16 species of viviparous freshwater snails. These snails show not only a high degree of inter- and intraspecific morphological differentiation, but also of molecular divergence. A mtDNA based molecular phylogeny reveals several old lineages which independently colonized the lakes, and within each clade bursts of very recent radiation with unresolved relationships on the population and species level. The rates of molecular and morphological evolution have been found to be highly divergent in lake species as opposed to widespread riverine taxa, pointing to strong selective pressures on certain traits associated with transition to a lacustrine environment and habitat use within the lakes. The proposed study therefore aims to test various alternative hypotheses of speciation factors and processes relevant for the evolution of the lake gastropod diversity in space by (1) uncovering patterns of gene flow and genealogical relationships within and among key populations of major clades and (2) getting base-line data on ecological differentiation for these populations in order to (3) quantify phenotype-environment correlations and (4) evaluate trait utility. The emerging speciation pattern for the gastropods shall be tested for congruence with those gained - in a cooperative approach with other researchers - from endemic fishes and crabs.

辐射背景下的物种形成被认为是创造生物多样性的关键过程。湖泊中的适应性辐射为研究物种形成的生态学提供了几乎完美的条件，淡水腹足类是理想的模式生物。印度尼西亚苏拉威西岛上古老的马利利湖拥有大约16种胎生淡水蜗牛的特有物种群。这些蜗牛不仅表现出高度的种间和种内形态分化，而且分子分歧。基于mtDNA的分子进化揭示了几个独立殖民湖泊的古老谱系，并且在每个进化枝中爆发了最近的辐射，在种群和物种水平上具有未解决的关系。分子和形态进化的速度已被发现是非常不同的湖泊物种，而不是广泛的河流类群，指向强大的选择压力与过渡到湖泊环境和栖息地使用的湖泊内的某些特征。因此，拟议的研究旨在通过以下方式测试与湖泊腹足类空间多样性演变相关的物种形成因素和过程的各种替代假设：（1）揭示主要分支关键种群内和之间的基因流和系谱关系模式，（2）获得这些种群生态分化的基线数据，以便（3）量化表型-环境相关性，（4）评估特质效用。应与其他研究人员合作，检验腹足类新出现的物种形成模式是否与从特有鱼类和螃蟹中获得的物种形成模式一致。