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

巴塔哥尼亚冰原自末次盛冰期以来的演变不仅对古气候研究有意义，因为它们是目前极地地区以外最大的冰原，而且对南美洲南锥体的人口也有意义。虽然现有的数据表明，在末次盛冰期冰盖的西部延伸不知何故离岸海岸，有一些证据表明，它并不像一般认为的那样均匀。沿着西部边缘沿着可能存在无冰区域，这些区域可能深深地嵌入末次冰期冰盖。一方面，这些地区可能是人们乘船向南迁移到火之地的地方，另一方面，这些地区也是某些生物的避难所。这一假设将通过一种新的方法进行测试，使用分子标记，包括AFLP指纹的窄范围和低流动性的陆地腹足类是现存的沿着智利南部太平洋海岸。通过这种方法，可以显示某些腹足动物种群是否在LGM期间持续存在，或者它们是否在冰消退后迁移到现代栖息地。将在生物地理和古环境调查的背景下评估所获得的数据。将进一步发展在此采用的综合办法，以便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.