Koteja P, Swallow J G, Carter P A, Garland T
Department of Zoology, 430 Lincoln Drive, University of Wisconsin-Madison, Madison, Wisconsin 53706-1381.
Physiol Biochem Zool. 1999 Mar-Apr;72(2):238-49. doi: 10.1086/316653.
Laboratory house mice (Mus domesticus) that had experienced 10 generations of artificial selection for high levels of voluntary wheel running ran about 70% more total revolutions per day than did mice from random-bred control lines. The difference resulted primarily from increased average velocities rather than from increased time spent running. Within all eight lines (four selected, four control), females ran more than males. Average daily running distances ranged from 4.4 km in control males to 11.6 km in selected females. Whole-animal food consumption was statistically indistinguishable in the selected and control lines. However, mice from selected lines averaged approximately 10% smaller in body mass, and mass-adjusted food consumption was 4% higher in selected lines than in controls. The incremental cost of locomotion (grams food/revolution), computed as the partial regression slope of food consumption on revolutions run per day, did not differ between selected and control mice. On a 24-h basis, the total incremental cost of running (covering a distance) amounted to only 4.4% of food consumption in the control lines and 7.5% in the selected ones. However, the daily incremental cost of time active is higher (15.4% and 13.1% of total food consumption in selected and control lines, respectively). If wheel running in the selected lines continues to increase mainly by increases in velocity, then constraints related to energy acquisition are unlikely to be an important factor limiting further selective gain. More generally, our results suggest that, in small mammals, a substantial evolutionary increase in daily movement distances can be achieved by increasing running speed, without remarkable increases in total energy expenditure.
经历了十代高水平自愿轮转跑步人工选择的实验用家鼠（小家鼠），每天的总转数比随机繁殖对照组品系的小鼠多约70%。这种差异主要源于平均速度的提高，而非跑步时间的增加。在所有八个品系（四个选择品系、四个对照品系）中，雌性比雄性跑得更多。平均每日跑步距离从对照雄性的4.4千米到选择雌性的11.6千米不等。选择品系和对照品系的全动物食物消耗量在统计学上无显著差异。然而，选择品系的小鼠平均体重约小10%，且选择品系的体重校正食物消耗量比对照品系高4%。将食物消耗量对每日跑步转数的偏回归斜率计算得出的运动增量成本（克食物/转），在选择品系和对照品系的小鼠之间没有差异。以24小时为基础，跑步的总增量成本（涵盖一定距离）在对照品系中仅占食物消耗量的4.4%，在选择品系中占7.5%。然而，每日活跃时间的增量成本更高（分别占选择品系和对照品系总食物消耗量的15.4%和13.1%）。如果选择品系中的轮转跑步主要继续通过速度增加来提高，那么与能量获取相关的限制不太可能是限制进一步选择增益的重要因素。更一般地说，如果选择品系中的轮转跑步主要继续通过速度增加来提高，那么与能量获取相关的限制不太可能是限制进一步选择增益的重要因素。更普遍地说，我们的结果表明，在小型哺乳动物中，可以通过提高跑步速度实现每日运动距离的大幅进化增加，而总能量消耗不会显著增加。
