Leibold Mathew A, Tessier Alan J, West Colin T
Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, Illinois, 60637.
Kellogg Biological Station and Department of Zoology, Michigan State University, Hickory Corners, Michigan, 49060.
Evolution. 1994 Aug;48(4):1324-1332. doi: 10.1111/j.1558-5646.1994.tb05316.x.
Daphnia pulicaria from three different populations were observed to express within-population variation in habitat-choice behavior in field assays. Individuals from different habitats (i.e., lake depths) were isolated and cultured as clonal lines under standard conditions. Habitat choices by clonal descendants were then estimated in the field, using replicate experimental columns. There was significant heritable and ontogenetic variation in habitat choice, but the heritable effect was small relative to the phenotypic variation of the original isolates. In a second set of experiments, D. pulicaria that were acclimatized to different habitats showed a strong tendency to choose the habitat to which they had been acclimatized. These data suggest that a given genotype can use a wide range of habitats, given appropriate acclimatization. Although genetic variation is significant, we hypothesize that natural selection on correlated ecological traits is more likely to maintain patterns of genotypic segregation among habitats in Daphnia.
在野外试验中观察到，来自三个不同种群的蚤状溞在栖息地选择行为上表现出种群内变异。将来自不同栖息地（即湖泊深度）的个体分离出来，并在标准条件下作为克隆系进行培养。然后，使用重复的实验柱在野外估计克隆后代的栖息地选择。栖息地选择存在显著的遗传和个体发育变异，但相对于原始分离株的表型变异，遗传效应较小。在第二组实验中，适应不同栖息地的蚤状溞表现出强烈的倾向，即选择它们已适应的栖息地。这些数据表明，给定的基因型在适当适应的情况下可以利用广泛的栖息地。尽管遗传变异很显著，但我们假设，对相关生态性状的自然选择更有可能维持蚤状溞不同栖息地间的基因型分离模式。
