Data from: No relationship between canalization and developmental stability in the skull of a natural population of Mastomys natalensis (Rodentia: Muridae)

The aim of the present work was to investigate the relationship between canalization and developmental stability under varying environmental conditions. Three different cohorts of Mastomys natalensis (Rodentia, Muridae), displaying different growth trajectories, were analyzed by means of Geometric morphometrics. A set of 23 landmarks was digitalized on the dorsal skull of 292 specimens from Morogoro (Tanzania). Patterns of among- and within-individual (measured as fluctuating asymmetry) variation were assessed and compared among and within the three groups in order to test for the presence of a common mechanism between canalization and developmental stability. Results showed that there was no congruence between canalization and developmental stability: 1) levels of FA and among-individual variation varied in a discordant fashion, 2) no correspondence between variance-covariance matrix of among- and within individual variation was found, 3) environmental effects were able to alter the covariance structure of among- individual variation living patterns associated with fluctuating asymmetry unaffected. These findings support the view of multiple mechanisms underlying developmental buffering of shape variation.

本研究旨在探究不同环境条件下发育渠化（canalization）与发育稳定性（developmental stability）之间的关联。本研究选取3个具有不同生长轨迹的Natal多乳鼠（Mastomys natalensis，啮齿目，鼠科）队列，采用几何形态测量学（Geometric morphometrics）方法开展分析。研究人员从坦桑尼亚莫罗戈罗地区的292份标本的背侧颅骨上，数字化采集了23个解剖地标点。本研究对个体间与个体内（以波动不对称（fluctuating asymmetry）作为衡量指标）的变异模式进行评估，并在3个组间及组内开展比较，以检验发育渠化与发育稳定性之间是否存在共同作用机制。结果表明，发育渠化与发育稳定性之间并不存在一致性：1）波动不对称水平与个体间变异的变化趋势不协调；2）未发现个体间变异与个体内变异的方差-协方差矩阵存在对应关系；3）环境效应能够改变个体间变异的协方差结构，但与波动不对称相关的模式未受影响。上述研究结果支持了「形态变异的发育缓冲存在多重机制」这一学术观点。