摘要环境胁迫是生物扩散的重要原因之一。同时,分散过程本身可以引起和/或增加分散个体对压力的敏感性。因此,原则上,压力既可以作为分散的原因,也可以作为分散的成本。我们使用果蝇研究了关键环境压力(干燥)的这些潜在对比作用。通过调节水和休息的可用性,我们询问(a)分散剂是否是更容易受到干燥压力的个体,(b)分散剂在降低对干燥应力的抵抗力方面付出了代价,(C)扩散演化改变了扩散的干燥成本,和(d)女性支付繁殖费用的传播。我们发现干燥是两性分散的明显原因,随着干燥持续时间的增加,男性和女性的扩散倾向都增加。然而,分散的干燥成本是男性偏见,不受扩散演化影响的趋势。相反,雌性付出了繁殖力分散的代价。我们讨论了干燥和分散之间的复杂关系,这可能导致积极和消极的关联。此外,这里强调的性别差异可能会转化为运动模式的差异,从而导致性别偏见的传播模式。
AbstractEnvironmental stress is one of the important causes of biological dispersal. At the same time, the process of dispersal itself can incur and/or increase susceptibility to stress for the dispersing individuals. Therefore, in principle, stress can serve as both a cause and a cost of dispersal. We studied these potentially contrasting roles of a key environmental stress (desiccation) using Drosophila melanogaster. By modulating water and rest availability, we asked whether (a) dispersers are individuals that are more susceptible to desiccation stress, (b) dispersers pay a cost in terms of reduced resistance to desiccation stress, (c) dispersal evolution alters the desiccation cost of dispersal, and (d) females pay a reproductive cost of dispersal. We found that desiccation was a clear cause of dispersal in both sexes, as both male and female dispersal propensity increased with increasing duration of desiccation. However, the desiccation cost of dispersal was male biased, a trend unaffected by dispersal evolution. Instead, females paid a fecundity cost of dispersal. We discuss the complex relationship between desiccation and dispersal, which can lead to both positive and negative associations. Furthermore, the sex differences highlighted here may translate into differences in movement patterns, thereby giving rise to sex-biased dispersal patterns.