Comparative Quantitative Genetics of the Pelvis in Four-Species of Rodents and the Conservation of Genetic Covariance and Correlation Structure
Comparative Quantitative Genetics of the Pelvis in Four-Species of Rodents and the Conservation of Genetic Covariance and Correlation Structure
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DOI：
10.1007/s11692-022-09559-z
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发表时间：
2022-02-21
影响因子：
2.5
通讯作者：
Steppan，Scott J.
中科院分区：
文献类型：
--
作者：
Saltzberg，Carl J.;Walker，Laura;Steppan，Scott J.
数量遗传学是在微进化尺度上预测表型进化的有力工具。这种预测能力主要来自Lande方程（Δz =Gβ），这是育种者方程的多变量扩展，其中表型变化（Δz）由遗传协方差（G）和选择（β）预测。进化生物学家提出，如果预测扩展到更长的时间尺度，数量遗传学可以在微观和宏观进化模式之间架起桥梁。虽然在数学上是可能的，但跨代或跨物种进行定量遗传预测是有争议的，主要是假设G矩阵的长期稳定性。在这里，我们通过对来自南美洲的两种乙状齿啮齿动物（叶耳鼠Phyllotis vaccarum和P.）进行全同胞和半同胞繁殖计划，测试了宏观进化时间尺度上的稳定性。Darwini和估计了八个骨盆特征的G矩阵。为了扩大我们的系统发育广度，我们纳入了两个额外的G矩阵测量相同的性状，从科恩和阿奇利的1988年的研究鼠啮齿动物小家鼠和褐家鼠。使用系统发育的比较框架和四个单独的矩阵的分歧或相似性的指标，我们发现物种G矩阵和时间之间的进化分歧之间没有显着的关联，支持的假设，至少有一些结构的稳定性。然而，系统发育的样本量必然很小。我们认为，协方差结构的小波动可以迅速发生，但潜在的发展调节，防止显着的分歧在宏观进化尺度，类似于一个Ornstein-Uhlenbeck模式。需要扩大分类学取样来检验这一建议。
Quantitative genetics is a powerful tool for predicting phenotypic evolution on a microevolutionary scale. This predictive power primarily comes from the Lande equation (Δz̅=Gβ), a multivariate expansion of the breeder’s equation, where phenotypic change (Δz̅) is predicted from the genetic covariances (G) and selection (β). Typically restricted to generational change, evolutionary biologists have proposed that quantitative genetics could bridge micro- and macroevolutionary patterns if predictions were expanded to longer timescales. While mathematically possible, making quantitative genetic predictions across generations or species is contentiously debated, principally in assuming long-term stability of theG-matrix. Here we tested stability at a macroevolutionary timescale by conducting full- and half-sib breeding programs in two species of sigmodontine rodents from South America, the leaf-eared micePhyllotis vaccarumandP. darwiniand estimated theG-matrices for eight pelvic traits. To expand our phylogenetic breadth, we incorporated two additionalG-matrices measured for the same traits from Kohn & Atchley’s 1988 study of the murine rodentsMus musculusandRattus norvegicus. Using a phylogenetic comparative framework and four separate metrics of matrix divergence or similarity, we found no significant association between evolutionary divergence among speciesG-matrices and time, supporting the assumption of stability for at least some structures. However, the phylogenetic sample size is necessarily small. We suggest that small fluctuations in covariance structure can occur rapidly, but underlying developmental regulation prevents significant divergence at macroevolutionary scales, analogous to an Ornstein–Uhlenbeck pattern. Expanded taxonomic sampling will be needed to test this suggestion.