Are offspring begging levels exaggerated beyond the parental optimum? Evidence from a bidirectional selection experiment

Parental care involves elaborate behavioural interactions between parents and their offspring, with offspring stimulating their parents via begging to provision resources. Thus, begging has direct fitness benefits as it enhances offspring growth and survival. It is nevertheless subject to a complex evolutionary trajectory, because begging may serve as a means for the offspring to manipulate parents in the context of evolutionary conflicts of interest. Furthermore, it has been hypothesized that begging is coadapted and potentially genetically correlated with parental care traits as a result of social selection. Further experiments on the causal processes that shape the evolution of begging are therefore essential. We applied bidirectional artificial selection on begging behaviour, using canaries (Serinus canaria) as a model species. We measured the response to selection, the consequences for offspring development, changes in parental care traits, here the rate of parental provisioning, a...亲本抚育（parental care）指亲本与子代之间复杂精细的行为互动，子代通过乞食行为（begging）刺激亲本为其提供资源。因此，乞食行为可通过提升子代的生长与存活概率，使其获得直接的适合度收益。然而，乞食行为的演化轨迹却十分复杂，因为在演化利益冲突的背景下，乞食可能成为子代操控亲本的手段。此外，有假说提出，受社会选择作用影响，乞食行为可能与亲本抚育性状发生共适应，并潜在存在遗传相关性。因此，针对塑造乞食行为演化的因果过程开展进一步实验至关重要。 本研究以金丝雀（Serinus canaria）为模式物种，对乞食行为开展双向人工选择。我们测定了选择响应、对子代发育的影响以及亲本抚育性状的变化——此处指亲本供食速率，以及……