Freshwater planarians may have a wide geographical range despite their assumed low vagility. Found across four continents, Dugesia may have either an ancient origin on a large palaeo landmass, followed by colonisation in different regions before continental fragmentation, or a more recent origin and subsequent transoceanic dispersal. We seek to resolve between these two hypotheses.

中文翻译：

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走出非洲的三种传播路线：淡水涡虫令人费解的生物地理历史

淡水涡虫可能具有广泛的地理范围，尽管它们被假定为低流动性。发现于四大洲的杜格西亚可能有一个古老的起源于一个巨大的古陆块，然后在大陆分裂之前在不同地区进行殖民化，或者一个更新的起源和随后的跨洋扩散。我们寻求解决这两个假设之间的问题。