Data from: Direct and indirect genetic effects in life history traits of flour beetles (Tribolium castaneum)

Indirect genetic effects (IGEs) are the basis of social interactions among conspecifics, and can affect genetic variation of non-social as well as social traits. We used flour beetles (Tribolium castaneum) of two phenotypically distinguishable populations to estimate genetic (co)variances and the effect of IGEs on three life-history traits: development time (DT), growth rate (GR), and pupal body mass (BM). We found that GR was strongly affected by social environment with IGEs accounting for 18% of the heritable variation. We also discovered a sex-specific social effect: male ratio in a group significantly affected both GR and BM. That is, beetles grew larger and faster in male-biased social environments. Such sex-specific IGEs have not previously been demonstrated in a non-social insect. Our results show that beetles that achieve a higher BM do so via a slower GR in response to social environment. Existing models of evolution in age-structured or stage-structured populations do not account for IGEs of social cohorts. It is likely that such IGEs have played a key role in the evolution of developmental plasticity shown by Tenebrionid larvae in response to density. Our results document an important source of genetic variation for GR, often overlooked in life-history theory.间接遗传效应（Indirect genetic effects，IGEs）是同种个体间社会互动的基础，可同时影响非社会与社会性状的遗传变异。本研究以两个表型可区分种群的赤拟谷盗（*Tribolium castaneum*）为实验材料，估算了遗传（共）方差，并解析了间接遗传效应对3种生活史性状的影响：发育时间（development time, DT）、生长速率（growth rate, GR）及蛹体质量（pupal body mass, BM）。 研究结果显示，生长速率受社会环境的影响极为显著，间接遗传效应可解释18%的遗传变异。此外，本研究还发现了性别特异性的社会效应：种群内的雄性比例会显著影响生长速率与蛹体质量。具体而言，在偏雄性的社会环境中，赤拟谷盗的生长速度更快、个体体型更大。这类性别特异性的间接遗传效应此前从未在非社会性昆虫中被证实。 本研究结果表明，在特定社会环境下，最终获得更高蛹体质量的赤拟谷盗，其生长速率反而更慢。现有针对年龄结构或阶段结构种群的进化模型，均未纳入社会集群的间接遗传效应。此类间接遗传效应很可能在拟步甲科幼虫对种群密度的发育可塑性进化过程中发挥了关键作用。本研究明确了生长速率遗传变异的一个重要来源，而这一来源在生活史理论中常被忽视。