Data from: Functional traits in red flour beetles: the dispersal phenotype is associated with leg length but not body size nor metabolic rate

1. Individuals vary in their ability to disperse. Much of this variation can be described by covarying phenotypic traits that are related to dispersal (constituting the ‘dispersal phenotype’ or ‘dispersal syndrome’), but the nature of the associations among these traits is not well understood. Unravelling the associations among traits that potentially constitute the dispersal phenotype provides a foundation for understanding evolutionary trade-offs due to variation in dispersal. 2. Here, we tested five predictions pertaining to the relationships among physiological, morphological and movement traits that are associated with dispersal, using a species with a long history as a laboratory model for studying ecological phenomena, red flour beetles (Tribolium castaneum). 3. We identified a dominant axis of movement ability that describes variation in dispersal-related movement traits. Individuals that scored positively on this axis moved at higher speed, travelled longer distances, had lower movement intermittency and dispersed quicker to a specified area. 4. Relative leg length, but not body size nor routine metabolic rate related positively with movement ability, indicating a likely mechanistic relationship between increased stride length and movement ability. 5. Our data suggest that the dispersal phenotype may be more strongly linked to morphological traits than physiological ones. We demonstrate that associations among many functional traits do not necessarily conform to a priori expectations, and predict that the substantial intraspecific variation in trait values may be important for selection. Movement is a complex behavioural trait, but it has a mechanistic basis in locomotor morphology that warrants further exploration.

1. 个体的扩散能力存在个体差异。这类差异大多可通过与扩散相关的协变表型性状来表征，此类性状共同构成「扩散表型（dispersal phenotype）」或「扩散综合征（dispersal syndrome）」，但这些性状间关联的本质仍未被充分阐明。解析潜在构成扩散表型的各类性状间的关联，是理解扩散变异所引发的进化权衡的基础。2. 本研究以长期作为生态学现象研究实验室模型物种的赤拟谷盗（Tribolium castaneum）为研究对象，针对与扩散相关的生理性状、形态性状及运动性状间的关联提出5项预测并开展验证。3. 本研究识别出一条主导运动能力的主轴，可用于阐释与扩散相关的运动性状的变异：在该主轴上得分较高的个体，运动速度更快、移动距离更长、运动间歇性更低，且能更快抵达指定区域。4. 相对腿长与运动能力呈正相关，而体型与常规代谢率则无此关联，这提示步幅提升与运动能力增强之间存在潜在的机制性关联。5. 本研究数据表明，扩散表型与形态性状的关联可能较其与生理性状的关联更为紧密。我们证实，诸多功能性状间的关联未必符合先验预期，并推测性状值存在的显著种内变异可能对选择作用至关重要。运动是一类复杂的行为性状，但其运动形态学层面存在机制性基础，这一研究方向值得进一步探索。