Abstract：
Interspecific competition can hinder populations from evolutionarily adapting to abiotic environments, particularly by reducing population size and niche space; and feedback may arise between competitive ability and evolutionary adaptation. Here we studied populations of two model bacterial species, Escherichia coli and Pseudomonas fluorescens, that evolved in monocultures and cocultures for approximately 2400 generations at three temperatures. The two species showed a reversal in competitive dominance in cocultures along the temperature gradient. Populations from cocultures where they had been competitively dominant showed the same magnitude of fitness gain as those in monocultures. However, competitively inferior populations in cocultures showed limited abiotic adaptation compared with those in monocultures. The inferior populations in cocultures were also more likely to evolve weaker interspecific competitive ability, or go extinct. The possible competitive ability-adaptation feedback may have crucial consequences for population persistence.
摘要：
种间竞争会阻碍种群进化适应非生物环境，特别是通过减少人口规模和生态位空间；竞争能力和进化适应之间可能会产生反馈。在这里，我们研究了两种模式细菌的种群，大肠杆菌和荧光假单胞菌，在三个温度下以单种培养和共培养方式进化了大约2400代。这两个物种在温度梯度的共培养中显示出竞争优势的逆转。在竞争中占主导地位的共文化群体显示出与单一文化相同的健身增益。然而,与单种培养相比，共培养中竞争性较差的种群显示出有限的非生物适应性。共培养中的劣等群体也更有可能进化出较弱的种间竞争能力，或者灭绝。可能的竞争能力-适应能力反馈可能对人口持久性产生至关重要的影响。
