Donker M H, Zonneveld C, van Straalen N M
Department of Ecology and Ecotoxicology, Faculty of Biology, Vrije Universiteit, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
Department of Theoretical Biology, Faculty of Biology, Vrije Universiteit, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
Oecologia. 1993 Dec;96(3):316-323. doi: 10.1007/BF00317500.
Organisms inhabiting metal-contaminated areas can be stressed by metal exposure and are possibly subject to selection, resulting in increased metal tolerance and changes in growth and/or reproduction characteristics. In a previous study it was found that in the terrestrial isopod Porcellio scaber, sampled from the vicinity of a zine smelter, the body size was small and the brood size was large compared to isopods from a reference area. To assess whether these differences were due to genetic differentiation between strains, isopods collected from a reference wood, a zinc smelter area and a lead mine were cultured on non-polluted food, while growth, reproduction and metal concentrations were studied in first and second laboratory generations. The isopods from the three populations differed in age and weight at first reproduction, although there were hardly any differences in growth. The females of the mine and the smelter population started to reproduce earlier, at a lower weight, which resulted in fewer young per female. However, reproductive allocation (=wight of young relative to the weight of the mother) was higher in mine and smelter isopods. We conclude that the isopods at the metal-contaminated sites have been selected for early reproduction and increased reproductive allocation. The results indicate that populations inhabiting metal-polluted sites have probably undergone evolutionary changes. This study showed that growth and reproduction characteristics of different populations under laboratory conditions may provide information on selection processes in the field.
栖息在金属污染区域的生物可能会因接触金属而受到压力，并可能面临选择，从而导致金属耐受性增强以及生长和/或繁殖特征发生变化。在之前的一项研究中发现，从锌冶炼厂附近采集的陆生等足动物粗糙卷甲虫，与来自参考区域的等足动物相比，体型较小但繁殖窝数较多。为了评估这些差异是否是由于品系间的遗传分化所致，将从参考树林、锌冶炼厂区域和铅矿采集的等足动物在无污染食物上进行培养，同时对第一代和第二代实验室培养的等足动物的生长、繁殖和金属浓度进行研究。来自这三个种群的等足动物在首次繁殖时的年龄和体重存在差异，尽管在生长方面几乎没有差异。矿区和冶炼厂种群的雌性等足动物开始繁殖的时间更早，体重更低，这导致每只雌性等足动物的幼崽数量更少。然而，矿区和冶炼厂的等足动物的繁殖分配（=幼崽体重相对于母亲体重）更高。我们得出结论，金属污染位点的等足动物已被选择用于早期繁殖和增加繁殖分配。结果表明，栖息在金属污染位点的种群可能经历了进化变化。这项研究表明，不同种群在实验室条件下的生长和繁殖特征可能提供有关野外选择过程的信息。
