Data from: Environmental effects on the detection of adaptation

Detecting adaptation involves comparing the performance of populations evolving in different environments. This detection may be confounded by effects due to the environment experienced by organisms prior to the test. We tested whether such confounding effects occur, using spider-mite selection lines on two novel hosts and one ancestral host, after 15 generations of selection. Mites were either sampled directly from the selection lines, or subjected to a common juvenile or to a common maternal environment, mimicking the most frequent environmental manipulations. These environments strongly affected all life-history traits. Moreover, the detection of adaptation and of correlated responses on the ancestral host was inconsistent among environments in almost 20% of the cases. Indeed, we did not detect responses unambiguously for any life-history trait. This inconsistency was due to differential environmental effects on lines from different selection regimes. Therefore the detection of adaptation requires a careful control of these environmental effects.

适应性（adaptation）检测需通过比较不同环境下演化种群的表现来实现。但该类检测可能会因受试生物在测试前经历的环境所带来的混杂效应，导致结果出现混淆。本研究以在两种新宿主与一种原始宿主上历经15代选择培育的叶螨（spider-mite）选择系为实验材料，检验了此类混杂效应是否存在。实验中，叶螨样本要么直接取自选择系，要么被置于统一幼期环境或统一母代环境中，以此模拟最常见的环境操控方式。上述环境对所有生活史性状（life-history traits）均产生了显著影响。此外，在近20%的案例中，针对原始宿主的适应性检测与相关响应检测在不同环境间的结果并不一致。实际上，我们并未在任何生活史性状中明确检测到响应结果。这种不一致性源于不同环境效应对不同选择培育系的影响存在差异。因此，适应性检测需对这类环境效应进行严格管控。