Department of Biology, University of Nevada, Reno, NV 89557, USA.
J Evol Biol. 2010 Sep 1;23(9):1868-77. doi: 10.1111/j.1420-9101.2010.02053.x. Epub 2010 Aug 4.
The metabolic distinction between endotherms and ectotherms is profound. Whereas the ecology of metabolic rates is well studied, how endotherms evolved from their ectothermic ancestors remains unclear. The aerobic capacity model postulates that a genetic constraint between resting and maximal metabolism was essential for the evolution of endothermy. Using the multivariate breeders' equation, I illustrate how the (i) relative sizes of genetic variances and (ii) relative magnitudes of selection gradients for resting and maximal metabolism affect the genetic correlation needed for endothermy to have evolved via a correlated response to selection. If genetic variances in existing populations are representative of ancestral conditions, then the aerobic capacity model is viable even if the genetic correlation was modest. The analyses reveal how contemporary data on selection and genetic architecture can be used to test hypotheses about the evolution of endothermy, and they show the benefits of explicitly linking physiology and quantitative genetic theory.
温血动物和变温动物之间的代谢区别是深刻的。尽管代谢率的生态学已经得到了很好的研究，但温血动物如何从它们的变温动物祖先进化而来仍然不清楚。有氧能力模型假设，休息和最大代谢之间的遗传限制对于温血动物的进化是至关重要的。我使用多元育种者方程来说明，（i）遗传方差的相对大小，以及（ii）休息和最大代谢的选择梯度的相对大小如何影响通过对选择的相关反应进化为温血动物所需的遗传相关性。如果现有种群中的遗传方差代表了祖先条件，那么即使遗传相关性适中，有氧能力模型也是可行的。这些分析揭示了如何利用当代关于选择和遗传结构的数据来检验关于温血动物进化的假设，并且它们展示了明确将生理学和数量遗传理论联系起来的好处。
