Schrader Matthew, Jarrett Benjamin J M, Rebar Darren, Kilner Rebecca M
Department of Biology, The University of the South, Sewanee, TN 37383, USA
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
Proc Biol Sci. 2017 Sep 13;284(1862). doi: 10.1098/rspb.2017.1295.
Cryptic evolution occurs when evolutionary change is masked by concurrent environmental change. In most cases, evolutionary changes in the phenotype are masked by changing abiotic factors. However, evolutionary change in one trait might also be masked by evolutionary change in another trait, a phenomenon referred to as evolutionary environmental deterioration. Nevertheless, detecting this second type of cryptic evolution is challenging and there are few compelling examples. Here, we describe a likely case of evolutionary environmental deterioration occurring in experimental burying beetle () populations that are adapting to a novel social environment that lacks post-hatching parental care. We found that populations rapidly adapted to the removal of post-hatching parental care. This adaptation involved clear increases in breeding success and larval density (number of dispersing larvae produced per gram of breeding carcass), which in turn masked a concurrent increase in the mean larval mass across generations. This cryptic increase in larval mass was accomplished through a change in the reaction norm that relates mean larval mass to larval density. Our results suggest that cryptic evolution might be commonplace in animal families, because evolving trophic and social interactions can potentially mask evolutionary change in other traits, like body size.
当进化变化被同时发生的环境变化所掩盖时，就会发生隐秘进化。在大多数情况下，表型的进化变化被不断变化的非生物因素所掩盖。然而，一个性状的进化变化也可能被另一个性状的进化变化所掩盖，这种现象被称为进化环境恶化。尽管如此，检测这种第二种类型的隐秘进化具有挑战性，而且几乎没有令人信服的例子。在这里，我们描述了一个可能发生在实验埋葬甲虫（）种群中的进化环境恶化案例，这些种群正在适应一种缺乏孵化后亲代照料的新型社会环境。我们发现，种群迅速适应了孵化后亲代照料的缺失。这种适应包括繁殖成功率和幼虫密度（每克繁殖尸体产生的扩散幼虫数量）明显增加，这反过来又掩盖了各代幼虫平均质量的同时增加。幼虫质量的这种隐秘增加是通过反应规范的变化实现的，该规范将幼虫平均质量与幼虫密度联系起来。我们的结果表明，隐秘进化在动物家族中可能很常见，因为不断进化的营养和社会相互作用可能会潜在地掩盖其他性状（如体型）的进化变化。
