研究指出，遍布美国佛罗里达州的两种外来青蛙之所以能漂洋过海，从古巴来到佛州，它们搭乘的交通工具可能是漂流物。
据悉，两栖动物专家长久以来一直在争辩温室蟾及古巴树蛙到底从哪里来。这两种青蛙在加勒比海地区分布很广，但直到19世纪中叶，科学家才首度在佛罗里达岛礁发现它们的踪迹。100年后，这两种青蛙开始在美国本土站稳脚跟，并无止尽地繁衍到美国各地。直至今日，温室蟾的栖地北至亚拉巴马州，古巴树蛙则广布于佛罗里达南部沿岸地区。
宾州州立大学赫吉兹的科学团队相信，这两种青蛙数千年前就已来到佛州。可能的方法是攀附在植物上，漂流渡过狭窄的佛州海峡。
“搭乘漂流物飘洋过海的例子很多，甚至可跨越海洋。这些青蛙、特别是古巴树蛙，栖息于加勒比海许多无人岛上，它们很显然能四处迁移。除搭乘漂流物外，没其它办法抵达这些岛屿。”（生物谷Bioon.com）
生物谷推荐原文出处：
Biol. Lett. doi: 10.1098/rsbl.2010.1131
Origin of invasive Florida frogs traced to Cuba
Matthew P. Heinicke1,?, Luis M. Diaz2 and S. Blair Hedges1,*
Abstract
Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent.
