Abstract:
Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time. Often, a change in behavior is the first response to changing conditions. Behavioral flexibility can potentially improve an organism\'s chances to survive and reproduce. Currently, we lack an understanding on the time-scale such behavioral adjustments need, how they actually affect reproduction and survival and whether behavioral adjustments are sufficient in keeping up with changing conditions. We used house mice (Mus musculus) to test whether personality and life-history traits can adjust to an experimentally induced food-switch flexibly in adulthood or by intergenerational plasticity, that is, adjustments only becoming visible in the offspring generation. Mice lived in 6 experimental populations of semi-natural environments either on high or standard quality food for 4 generations. We showed previously that high-quality food induced better conditions and a less risk-prone personality. Here, we tested whether the speed and/ or magnitude of adjustment shows condition-dependency and whether adjustments incur fitness effects. Life-history but not personality traits reacted flexibly to a food-switch, primarily by a direct reduction of reproduction and slowed-down growth. Offspring whose parents received a food-switch developed a more active stress-coping personality and gained weight at a slower rate compared with their respective controls. Furthermore, the modulation of most traits was condition-dependent, with animals previously fed with high-quality food showing stronger responses. Our study highlights that life-history and personality traits adjust at different speed toward environmental change, thus, highlighting the importance of the environment and the mode of response for evolutionary models.
摘要:
环境条件通过人为扰动或自然地跨越空间和时间而不断变化。通常,行为的改变是对条件变化的第一反应。行为灵活性可以潜在地提高有机体的生存和繁殖机会。目前,我们缺乏对这种行为调整需要的时间尺度的理解,它们实际上如何影响繁殖和生存,以及行为调整是否足以跟上不断变化的条件。我们使用家鼠(Musmusculus)来测试人格和生活史特征是否可以在成年期或通过代际可塑性灵活地适应实验诱导的食物转换,也就是说,调整只会在后代中变得可见。小鼠在6个半自然环境的实验种群中生活了4代,无论是高质量的还是标准的食物。我们以前表明,高质量的食物会带来更好的条件和更低风险的性格。这里,我们测试了调整的速度和/或幅度是否显示条件依赖性,以及调整是否会产生适应性影响。生活史而不是人格特质对食物转换有灵活的反应,主要是通过直接减少繁殖和减缓增长。与各自的对照组相比,父母接受食物转换的后代发展出更积极的压力应对性格,体重增加速度较慢。此外,大多数性状的调制是依赖于条件的,以前用高质量食物喂养的动物表现出更强的反应。我们的研究强调,生活史和人格特质以不同的速度适应环境变化,因此,强调环境的重要性和进化模型的反应模式。