Data from: Causes of discordance between allometries at and above species-level: an example with aquatic beetles

Covariation among organismal traits is nearly universal, occurring both within and among species (static and evolutionary allometry, respectively). If conserved developmental processes produce similarity in static and evolutionary allometry, then when species differ in development, it should be expressed in discordance between allometries. Here, we investigate whether rapidly evolving developmental processes result in discordant static and evolutionary allometries attributable to trade-offs in resource acquisition, allocation, or growth across 30 species of aquatic beetles. The highly divergent sperm phenotypes of these beetles might be an important contributor to allometric evolution of testis and accessory gland mass through altered requirements for the production of sperm and seminal fluids. We documented extensive discordance between static and evolutionary allometries, indicating that allometric relationships are flexibly modified over short time periods but subject to constraint over longer time spans. Among species, sperm phenotype did not influence relative investment in accessory glands but was weakly associated with investment in testes. Furthermore, except when sperm were long and simple, sperm phenotype was not associated with species-specific modification of the allometry of testis/accessory gland mass and body size. Our results demonstrate the utility of allometric discordance to infer species differences in the provisioning and growth of concurrently developing traits.

生物性状间的协变现象几乎普遍存在，既存在于物种内部，也存在于物种种间，二者分别对应静态异速生长（static allometry）与进化异速生长（evolutionary allometry）。若保守的发育过程使得静态异速生长与进化异速生长呈现相似性，那么当不同物种的发育进程存在差异时，这种差异应体现为两类异速生长间的不一致性。本研究以30种水生甲虫为研究对象，探讨快速演化的发育过程是否会导致静态与进化异速生长出现不一致性，而这种不一致性可归因于资源获取、分配或生长过程中的权衡效应。这些甲虫高度分化的精子表型，可能通过改变精子与精液的生产需求，对睾丸及副腺质量的异速生长演化产生重要影响。本研究记录了静态与进化异速生长间广泛存在的不一致性，表明异速生长关系可在短时间尺度内被灵活调整，但在更长的时间跨度下仍受演化约束。在物种种间水平，精子表型对副腺的相对投入无显著影响，但与睾丸的投入存在微弱关联。此外，除精子呈长而简单形态的类群外，精子表型与物种特有的睾丸/副腺质量异速生长及体型的调控模式均无关联。本研究结果证实，利用异速生长不一致性可推断同步发育性状在资源供给与生长过程中的物种间差异。