Diversification in space and time across land and sea - a land snail genus conquering continents and islands

大洋岛屿在理解进化方面发挥了重要作用。加那利群岛栖息地多样，地质历史记载充分，为研究多样性和物种形成提供了特殊的先决条件。基于分子数据，我们将研究陆地蜗牛属Theba的多样性，该属的多样性中心位于加那利群岛，但最有可能起源于西北非洲，最近的14个物种中有5个出现在那里。总体而言，由于蜗牛扩散的潜力有限，蜗牛倾向于在较长的时间内保持分布模式，但Theba代表了物种形成研究的一个特别有趣的案例。在这些岛屿上有很好的化石记录，这将补充基于现存物种系统发育分析的推断。结合分子、古生物学和形态测量数据，将有助于在分子和形态水平上估计进化速度。非洲大陆和加那利群岛的分布提供了理想的分布对比，为多样化提供了不同的环境，物种和假定的亚种出现在同种、准或共生环境中，从而可以测试不同的多样化情景。因此，THEBA是一个令人兴奋的新模型系统，有望从经验的角度对进化过程进行极其深刻的洞察。

Oceanic islands have played an important role in understanding evolution. The Canary Islands offer exceptional preconditions to study diversification and speciation because of their habitat diversity and well documented geological history. Based on molecular data, we will study the diversification of the land snail genus Theba, which has its centre of diversity on the Canary Islands, but most likely originated in North West Africa, where five of the 14 recent species occur. In general, snails tend to preserve distribution patterns over longer periods of time due to their limited potential for dispersal, but Theba represents a particularly interesting case for studies of speciation. There is an excellent fossil record on the islands, which will complement the inferences based on the phylogenetic analyses of the extant species. In combination, molecular, paleontological and morphometric data will serve to estimate evolutionary rates on both the molecular and the morphological level. The distribution on the continent and the Canary Islands provides an ideal distributional contrast providing different settings for diversification, and species and putative subspecies occur in allo-, para- or sympatry allowing to test different scenarios of diversification. Theba thus is an exciting, new model system promising exceptionally deep insights in evolutionary processes from an empirical point of view.