Rohner Patrick
Department of Ecology, Behavior, and Evolution, University of California San Diego, La Jolla, CA, USA.
Proc Biol Sci. 2025 Sep;292(2054):20251039. doi: 10.1098/rspb.2025.1039. Epub 2025 Sep 3.
Some phenotypic dimensions are more developmentally variable than others. Such developmental variability (or bias) is common and uncontroversial. However, how and at what time scales these biases constrain or facilitate the emergence of standing genetic variation, plastic responses, as well as adaptation remains contentious. To investigate the extent to which developmental variability shapes genetic variation, plasticity and evolution, we first quantify developmental variability in the shape of the dung beetle foreleg-a functional trait critical for the excavation of breeding tunnels. We do so by testing how random developmental perturbations, manifesting themselves in fluctuating asymmetry, shape standing genetic variation within populations. Next, we investigate whether such developmental variability is aligned with thermal plasticity and recently evolved latitudinal variation. We find that, while developmental variability is a strong predictor of standing genetic (co)variance (i.e. the -matrix), latitudinal population differentiation and thermal plasticity were unrelated to developmental variability. This suggests that, while developmental variability may shape standing genetic variation, it does not seem to constrain the evolution of putatively adaptive population differentiation and plastic responses. At least in this system, developmental biases do not seem to constrain morphological differentiation on ecological time scales.
一些表型维度在发育过程中的变异性比其他维度更大。这种发育变异性（或偏差）很常见且没有争议。然而，这些偏差如何以及在何种时间尺度上限制或促进固定遗传变异、可塑性反应以及适应性的出现，仍然存在争议。为了研究发育变异性在多大程度上塑造了遗传变异、可塑性和进化，我们首先量化了蜣螂前腿形状的发育变异性——这是挖掘繁殖隧道的关键功能性状。我们通过测试随机发育扰动如何在波动不对称中表现出来，从而塑造种群内的固定遗传变异来做到这一点。接下来，我们研究这种发育变异性是否与热可塑性以及最近进化出的纬度变异一致。我们发现，虽然发育变异性是固定遗传（协）方差（即G矩阵）的有力预测指标，但纬度种群分化和热可塑性与发育变异性无关。这表明，虽然发育变异性可能塑造固定遗传变异，但它似乎并不限制假定的适应性种群分化和可塑性反应的进化。至少在这个系统中，发育偏差似乎不会在生态时间尺度上限制形态分化。
