A test of frequency-dependent selection in the evolution of a generalist phenotype,Ecology and Evolution

当前位置： X-MOL 学术 › Ecol. Evol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

A test of frequency-dependent selection in the evolution of a generalist phenotype
Ecology and Evolution ( IF 2.3 ) Pub Date : 2022-04-13 , DOI: 10.1002/ece3.8831
Stephanie A Blain ₁ , Louise Chavarie _{1,

2} , Mackenzie H Kinney ₁ , Dolph Schluter ₁

Affiliation

A solitary population of consumers frequently evolves to the middle of a resource gradient and an intermediate mean phenotype compared to a sympatric pair of competing species that diverge to either side via character displacement. The forces governing the distribution of phenotypes in these allopatric populations, however, are little investigated. Theory predicts that the intermediate mean phenotype of the generalist should be maintained by negative frequency-dependent selection, whereby alternate extreme phenotypes are favored because they experience reduced competition for resources when rare. However, the theory makes assumptions that are not always met, and alternative explanations for an intermediate phenotype are possible. We provide a test of this prediction in a mesocosm experiment using threespine stickleback that are ecologically and phenotypically intermediate between the more specialized stickleback species that occur in pairs. We manipulated the frequency distribution of phenotypes in two treatments and then measured effects on a focal intermediate population. We found a slight frequency-dependent effect on survival in the predicted direction but not on individual growth rates. This result suggests that frequency-dependent selection might be a relatively weak force across the range of phenotypes within an intermediate population and we suggest several general reasons why this might be so. We propose that allopatric populations might often be maintained at an intermediate phenotype instead by stabilizing or fluctuating directional selection.

中文翻译：

通才表型进化中频率依赖性选择的测试

与通过字符位移向任一侧分叉的同域竞争物种相比，孤独的消费者群体经常进化到资源梯度和中间平均表型的中间。然而，很少有人研究控制这些异域种群中表型分布的力量。理论预测，通才的中间平均表型应通过负频率依赖性选择来维持，其中交替的极端表型受到青睐，因为它们在稀有时会减少对资源的竞争。然而，该理论做出的假设并不总是得到满足，并且对中间表型的替代解释是可能的。我们在使用三棘棘鱼的中宇宙实验中提供了对这一预测的测试，三棘棘鱼在生态和表型上介于成对出现的更专业的棘鱼物种之间。我们操纵了两种治疗中表型的频率分布，然后测量了对焦点中间群体的影响。我们发现对预测方向的存活率有轻微的频率依赖性影响，但对个体增长率没有影响。这一结果表明，频率依赖性选择可能是中间群体中表型范围内相对较弱的力量，我们提出了几个一般原因。我们建议异域种群可能经常保持在中间表型，而不是通过稳定或波动的方向选择。

更新日期：2022-04-13

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南