Data from: Is the enhanced dispersal rate seen at invasion fronts a behaviourally plastic response to encountering novel ecological conditions?

As a population expands into novel areas (as occurs in biological invasions), the range edge becomes dominated by rapidly dispersing individuals—thereby accelerating the rate of population spread. That acceleration has been attributed to evolutionary processes (natural selection and spatial sorting), to which we add a third complementary process: behavioural plasticity. Encountering environmental novelty may directly elicit an increased rate of dispersal. When we reciprocally translocated cane toads (Rhinella marina) among study sites in southern Australia, the transported animals massively increased dispersal rates relative to residents (to an extent similar to the evolved increase between range-core versus invasion-front toad populations in Australia). The responses of these translocated toads show that even range-core toads are capable of the long-distance dispersal rates of invasion-front conspecifics and suggest that rapid dispersal (rather than evolving de novo) has simply been expanded from facultative to constitutive expression.当种群向新区域扩张时（正如生物入侵中发生的情形），其分布范围的边缘会被快速扩散的个体主导，进而加速种群的整体扩散速率。此前，这种扩散加速现象被归因于自然选择（natural selection）与空间分选（spatial sorting）两类进化过程，而我们在此提出第三种互补过程：行为可塑性（behavioural plasticity）。遭遇环境新异条件可直接引发扩散速率的提升。我们在澳大利亚南部的多个研究样地之间对蔗蟾（Rhinella marina）开展了互易移植实验，结果显示，被移植的个体相较于本地定居个体，扩散速率大幅提升——这一幅度与澳大利亚境内分布范围核心区（range-core）与入侵前沿（invasion-front）蔗蟾种群间的演化增幅相近。这些被移植蔗蟾的反应表明，即便是分布核心区的蔗蟾，也具备入侵前沿同种个体（conspecifics）的长距离扩散能力；同时该结果提示，快速扩散能力并非从头演化（evolving de novo）而来，而是从兼性表达拓展为了组成型表达。