Bacigalupe Leonardo D, Nespolo Roberto F, Bustamante Diego M, Bozinovic Francisco
Center for Advanced Studies in Ecology and Biodiversity, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 6513677 Santiago, Chile.
Evolution. 2004 Feb;58(2):421-9.
We explored how morphological and physiological traits associated with energy expenditure over long periods of cold exposure would be integrated in a potential response to natural selection in a wild mammal, Phyllotis danwini. In particular, we studied sustained energy expenditure (SusMR), the rate of expenditure fueled by concurrent energy intake, basal metabolic rate (BMR), and sustained metabolic scope (SusMS = SusMR/BMR), a measure of the reserve for sustained work. We included the masses of different central processing organs as an underlying factor that could have a mechanistic link with whole animal traits. Only the liver had heritability statistically different from zero (0.73). Physiological and morphological traits had high levels of specific environmental variance (average 70%) and postnatal common environmental variance (average 30%) which could explain the low heritabilities estimates. Our results, (1) are in accordance with previous studies in mammals that report low heritabilities for metabolic traits (SusMR, BMR, SusMS), (2) but not completely with previous ones that report high heritabilities for morphological traits (masses of central organs), and (3) provide important evidence of the relevance of postnatal common environmental variance to sustained energy expenditure.
我们探究了在长时间寒冷暴露过程中，与能量消耗相关的形态和生理特征如何在野生哺乳动物丹氏叶耳蝠（Phyllotis danwini）对自然选择的潜在响应中整合。具体而言，我们研究了持续能量消耗（SusMR）、由同时摄入的能量所驱动的消耗速率、基础代谢率（BMR）以及持续代谢范围（SusMS = SusMR/BMR，一种衡量持续工作储备的指标）。我们将不同中央处理器官的质量作为一个可能与整体动物特征存在机制联系的潜在因素纳入研究。只有肝脏的遗传力在统计学上显著不为零（0.73）。生理和形态特征具有高水平的特定环境方差（平均70%）和出生后共同环境方差（平均30%），这可以解释遗传力估计值较低的原因。我们的结果，（1）与之前关于哺乳动物代谢特征（SusMR、BMR、SusMS）遗传力较低的研究一致，（2）但与之前关于形态特征（中央器官质量）遗传力较高的研究并不完全一致，（3）为出生后共同环境方差与持续能量消耗的相关性提供了重要证据。
