Phylogeographical analyses of Patagonian terrestrial gastropods as a tool for understanding regional late Quaterary glacial dynamics

巴塔哥尼亚冰场自末次冰盛期(LGM)以来的演变不仅对古气候研究感兴趣，因为这些冰场目前是极地以外最大的冰场，而且对于南美洲南部锥体的人口也是如此。尽管现有数据表明，末次冰盖期间冰盖的西部延伸不知何故在近海，但有一些证据表明，它并不像人们普遍认为的那样均匀。西部边缘有可能存在无冰区，可能在冰盖上有相当深的凹陷。一方面，这些地区可以被乘船迁徙到火之地的人们使用，另一方面，这些地区也代表着某些生物的避难所。这一假设将通过一种新的方法进行验证，该方法使用分子标记，包括对智利南太平洋海岸现存的狭窄范围和低流动性的陆生腹足类进行AFLP指纹分析。通过这种方法，可以显示某些腹足类种群是否在末次冰期期间持续存在，或者它们是否在冰川消退后迁徙到现代栖息地。将在生物地理和古环境调查的背景下对将获得的数据进行评估。将进一步发展将在这里应用的综合方法，以获得更高的空间和时间分辨率。

The evolution of the Patagonian ice fields since the Last Glacial Maximum (LGM) is not only of interest in respect of palaeoclimate research, as these are presently the largest outside the polar regions, but also with regard to the peopling of the southern cone of South America. Although existing data indicate that the western extension of the ice sheets during LGM was somehow off shore, there is some evidence that it was not as homogeneous as generally believed. It is possible that ice free areas along the western edge existed, possibly quite deeply indented into the LGM ice sheets. On the one hand, these areas could have been used by people migrating by boats as far south as the Land of Fire, and on the other hand represented refugia for certain organisms. This hypothesis shall be tested by a new approach using molecular markers including AFLP fingerprinting on narrow-range and low mobility terrestrial gastropods being extant along the southern Chilean Pacific coast. With this approach, it can be shown whether certain gastropod populations sustained during the LGM or if they migrated to their modern habitats after the ice had retreated. The data to be obtained will be evaluated in the context of bio-geographical and palaeoenvironmental investigations. The combined approach to be applied here will be further developed in order to receive higher spatial and temporal resolutions.