Williams Yvette M, Williams Stephen E, Alford Ross A, Waycott Michelle, Johnson Christopher N
School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia.
Biol Lett. 2006 Dec 22;2(4):532-5. doi: 10.1098/rsbl.2006.0541.
We investigated the relationship between diet specialization and geographical range in Cophixalus, a genus of microhylid frogs from the Wet Tropics of northern Queensland, Australia. The geographical ranges of these species vary from a few square kilometres in species restricted to a single mountain top to the entire region for the widespread species. Although macroecological theory predicts that species with broad niches should have the largest geographical ranges, we found the opposite: geographically rare species were diet generalists and widespread species were diet specialists. We argue that this pattern is a product of extinction filtering, whereby geographically rare and therefore extinction-prone species are more likely to persist if they are diet generalists.
我们研究了澳大利亚昆士兰州北部湿热带地区的姬蛙科蛙类——姬蛙属（Cophixalus）中，食性特化与地理分布范围之间的关系。这些物种的地理分布范围差异很大，有的物种仅限于单个山顶，分布范围只有几平方公里，而分布广泛的物种则覆盖了整个地区。尽管宏观生态学理论预测，生态位宽泛的物种应该具有最大的地理分布范围，但我们却发现了相反的情况：地理分布范围狭窄的物种是食性通才，而分布广泛的物种是食性特化物种。我们认为，这种模式是灭绝筛选的结果，即地理分布范围狭窄因而容易灭绝的物种，如果是食性通才，则更有可能存活下来。
