Mueller L D
Department of Zoology, Washington State University, Pullman 99164-4220.
Proc Natl Acad Sci U S A. 1988 Jun;85(12):4383-6. doi: 10.1073/pnas.85.12.4383.
The theory of density-dependent natural selection predicts that populations kept at extreme densities should evolve different competitive abilities for limited resources. These predictions have been tested with laboratory populations of Drosophila melanogaster. Six independent populations were maintained in two environments, called r and K, for 128 generations. In the r environment, population sizes were small and resources for larvae and adults were abundant. In contrast the populations in the K environment were large and crowded, and resources, such as food and space, were in short supply. The relative competitive ability for food has been estimated for each population. Populations from the K environment consume food at a rate that is 58% greater than the average rate for the r population. The differentiation of competitive abilities in these populations is due to natural selection and is consistent with predictions from the theory of evolutionary ecology.
密度依赖型自然选择理论预测，处于极端密度下的种群应该会针对有限资源进化出不同的竞争能力。这些预测已在黑腹果蝇的实验室种群中得到验证。六个独立的种群在两种环境（分别称为r和K）中维持了128代。在r环境中，种群规模较小，幼虫和成虫的资源丰富。相比之下，K环境中的种群规模大且拥挤，食物和空间等资源短缺。已对每个种群的食物相对竞争能力进行了估计。来自K环境的种群消耗食物的速度比r种群的平均速度快58%。这些种群中竞争能力的分化是由于自然选择，并且与进化生态学理论的预测一致。
