Miura Osamu, Urabe Misako, Nishimura Tomohiro, Nakai Katsuki, Chiba Satoshi
Faculty of Agriculture and Marine Science Kochi University 200 Monobe Nankoku Kochi 783-8502 Japan.
Department of Ecosystem Studies, School of Environmental Science The University of Shiga Prefecture 2500 Hassaka-cho Hikone, Shiga 522-8533 Japan.
Evol Lett. 2018 Nov 30;3(1):43-54. doi: 10.1002/evl3.92. eCollection 2019 Feb.
Lake expansion that leads to the formation of new habitats has potential to drive intralacustrine diversification. The ancient Lake Biwa in central Japan has historically experienced substantial changes in the lake size, and it provides a useful system for evaluating the role of lake-size fluctuations in the diversification of endemic fauna. Here, we used genome-wide DNA analyses and reconstructed the diversification history of the endemic freshwater snails belonging to the subgenus with respect to the geological history of Lake Biwa. We found that two genetically distinct snail lineages independently colonized Lake Biwa and they concurrently and rapidly radiated into 15 extant species. A combination of paleontological evidence and molecular dating technique demonstrated that the radiation of was tightly linked to the latest enlargement of the lake about 0.4 million years ago and suggested that increased ecological opportunity associated with the lake expansion drove the rapid adaptive radiation. We propose that the snails in Lake Biwa offer a promising new system for understanding the association between the geological history of the lake and rapid intralacustrine diversification.
湖泊扩张导致新栖息地形成，这有可能推动湖内生物多样性的分化。日本中部的琵琶湖历史上经历了湖域大小的显著变化，它为评估湖域大小波动在特有动物群分化中的作用提供了一个有用的系统。在这里，我们利用全基因组DNA分析，结合琵琶湖的地质历史，重建了属于该亚属的特有淡水蜗牛的分化历史。我们发现，两个基因不同的蜗牛谱系独立地定殖于琵琶湖，并且它们同时迅速辐射分化为15个现存物种。古生物学证据和分子定年技术相结合表明，该蜗牛的辐射分化与约40万年前湖泊的最新扩张紧密相关，并表明与湖泊扩张相关的生态机会增加推动了快速适应性辐射。我们认为，琵琶湖中的该蜗牛为理解湖泊地质历史与湖内快速生物多样性分化之间的关联提供了一个很有前景的新系统。
