Data from: Resource allocation during ontogeny is influenced by genetic, developmental, and ecological factors in the horned beetle, Onthophagus taurus

Resource allocation trade-offs arise when developing organs are in competition for a limited pool of resources to sustain growth and differentiation. Such competition may constrain the maximal size to which structures can grow and may force a situation in which the evolutionary elaboration of one structure may only be possible at the expense of another. However, recent studies have called into question both the consistency and evolutionary importance of resource allocation trade-offs. This study focuses on a well-described trade-off between the horns and eyes of Onthophagus beetles and assesses the degree to which it is influenced by genetic, developmental and ecological conditions. Contrary to expectations, we observed that trade-off signatures (i) were mostly absent within natural populations, (ii) mostly failed to match naturally evolved divergences in horn investment among populations, (iii) were subject to differential changes in F1 populations derived from divergent field populations and (iv) remained largely unaffected by developmental genetic manipulations of horn investment. Collectively, our results demonstrate that populations subject to different ecological conditions exhibit different patterns of, and differential plasticity in, resource allocation. Further, variation in ecological conditions, rather than canalized developmental mechanisms, may determine whether and to what degree morphological structures engage in resource allocation trade-offs.

当发育中的器官为维持生长与分化而争夺有限资源时，便会产生资源分配权衡（resource allocation trade-off）。此类竞争可能会限制各结构的最大生长尺寸，甚至催生一种局面：某一结构的进化细化仅能以牺牲另一结构为代价。然而，近期研究对资源分配权衡的一致性及其进化重要性均提出了质疑。本研究聚焦于嗡蜣螂属（Onthophagus）甲虫的角与眼部之间已被充分阐释的权衡关系，并评估了遗传、发育及生态条件对该权衡关系的影响程度。与预期相悖的是，我们观察到权衡特征（trade-off signatures）呈现如下特点：(i) 在自然种群中大多缺失；(ii) 大多与种群间自然演化出的角投入差异不匹配；(iii) 源自不同野外种群的子一代（F1）种群会发生差异化变化；(iv) 基本不受角发育遗传操控的影响。综合而言，我们的研究结果表明，处于不同生态条件下的种群，其资源分配模式与可塑性均存在差异。此外，决定形态结构是否发生以及在多大程度上发生资源分配权衡的，或许是生态条件的变异，而非稳态化的发育机制。