Department of Biology, Wesleyan University, Middletown, Connecticut 06457.
Genetics. 1979 Apr;91(4):743-53. doi: 10.1093/genetics/91.4.743.
Heritabilities (from parent-offspring regression) and intraclass correlations of full sibs for a variety of traits were estimated from 225 litters of a heterogeneous stock (HS/Ibg) of laboratory mice. Initial variance partitioning suggested different adaptive functions for physiological, morphological and behavioral adjustments with respect to their thermoregulatory significance. Metabolic heat-production mechanisms appear to have reached their genetic limits, with little additive genetic variance remaining. This study provided no genetic evidence that body size has a close directional association with fitness in cold environments, since heritability estimates for weight gain and adult weight were similar and high, whether or not the animals were exposed to cold. Behavioral heat conservation mechanisms also displayed considerable amounts of genetic variability. However, due to strong evidence from numerous other studies that behavior serves an important adaptive role for temperature regulation in small mammals, we suggest that fluctuating selection pressures may have acted to maintain heritable variation in these traits.
从 225 窝异质种群（HS/Ibg）实验室老鼠的亲子回归中，估计了各种性状的全同胞遗传力（heritabilities）和同卵双生子相关系数（intraclass correlations）。初步的方差分解表明，生理、形态和行为调整对于其体温调节意义具有不同的适应功能。代谢产热机制似乎已经达到了其遗传极限，几乎没有剩余的加性遗传方差。这项研究没有提供遗传证据表明，在寒冷环境中，体型大小与适应性有密切的定向关联，因为体重增加和成年体重的遗传力估计值相似且较高，无论动物是否暴露于寒冷环境中。行为性热保护机制也表现出相当大的遗传变异性。然而，由于来自许多其他研究的有力证据表明，行为对于小型哺乳动物的体温调节具有重要的适应性作用，我们认为，波动的选择压力可能导致这些性状的可遗传变异得以维持。
