Conflict between biotic and climatic selective pressures acting on an extended phenotype in a subarctic, but not temperate, environment
Conflict between biotic and climatic selective pressures acting on an extended phenotype in a subarctic, but not temperate, environment
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生物和气候选择压力之间的冲突作用于亚北极而非温带环境中的扩展表型
DOI：
10.1098/rspb.2015.1585
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Paul R Martin
中科院分区：
文献类型：
--
作者：
Vanya G. Rohwer;F. Bonier;Paul R Martin
气候选择压力被认为主导着高纬度地区的生物选择压力。然而，很少有研究通过实验测试这些选择压力如何在不同的纬度上对特征产生不同的作用，因为特征很少独立于自然界中的有机体而被操纵。我们通过使用扩展的表型-活跃的鸟巢-克服了这一挑战，并在相隔14°纬度的亚北极和温带地点之间进行了相互移植实验。在亚北极地区，生物选择压力(捕食)有利于较小的非本地温带巢穴，而气候选择压力(温度)有利于较大的本地巢穴，特别是在较冷的温度下。相比之下，在温带地区，气候和生物选择压力对温带和亚北极地区的巢穴起到了类似的作用。我们的结果说明了亚北极地区在生物和气候选择压力下有利于巢穴形态和气候有利于当地巢穴形态之间的功能权衡。然而，在我们的温带地点，用于筑巢的时间和精力的分配权衡有利于较小的本地巢穴。我们的发现说明了物种地理范围最北端的生物和气候选择压力之间的冲突，并表明特征功能和特征精化之间的权衡在不同纬度之间的作用不同，从而造成了广泛的地理差异。
Climatic selective pressures are thought to dominate biotic selective pressures at higher latitudes. However, few studies have experimentally tested how these selective pressures differentially act on traits across latitudes because traits can rarely be manipulated independently of the organism in nature. We overcame this challenge by using an extended phenotype—active bird nests—and conducted reciprocal transplant experiments between a subarctic and temperate site, separated by 14° of latitude. At the subarctic site, biotic selective pressures (nest predation) favoured smaller, non-local temperate nests, whereas climatic selective pressures (temperature) favoured larger local nests, particularly at colder temperatures. By contrast, at the temperate site, climatic and biotic selective pressures acted similarly on temperate and subarctic nests. Our results illustrate a functional trade-off in the subarctic between nest morphologies favoured by biotic versus climatic selective pressures, with climate favouring local nest morphologies. At our temperate site, however, allocative trade-offs in the time and effort devoted to nest construction favour smaller, local nests. Our findings illustrate a conflict between biotic and climatic selective pressures at the northern extremes of a species geographical range, and suggest that trade-offs between trait function and trait elaboration act differentially across latitude to create broad geographic variation in traits.