Institute of Organismic and Molecular Evolution, Johannes Gutenberg University of Mainz, Hanns-Dieter-Hüsch-Weg 15, 55128, Mainz, Germany.
BMC Ecol Evol. 2021 Aug 30;21(1):163. doi: 10.1186/s12862-021-01890-x.
The reproductive division of labor of eusocial insects, whereby one or several queens monopolize reproduction, evolved in a context of high genetic relatedness. However, many extant eusocial species have developed strategies that decrease genetic relatedness in their colonies, suggesting some benefits of the increased diversity. Multiple studies support this hypothesis by showing positive correlations between genetic diversity and colony fitness, as well as finding effects of experimental manipulations of diversity on colony performance. However, alternative explanations could account for most of these reports, and the benefits of diversity on performance in eusocial insects still await validation. In this study, we experimentally increased worker diversity in small colonies of the ant Lasius niger while controlling for typical confounding factors.
We found that experimental colonies composed of workers coming from three different source colonies produced more larvae and showed more variation in size compared to groups of workers coming from a single colony.
We propose that the benefits of increased diversity stemmed from an improved division of labor. Our study confirms that worker diversity enhances colony performance, thus providing a possible explanation for the evolution of multiply mated queens and multiple-queen colonies in many species of eusocial insects.
在高度遗传相关的情况下，真社会性昆虫的生殖分工进化为一个或多个女王垄断繁殖。然而，许多现存的真社会性物种已经发展出降低其群体中遗传相关性的策略，这表明增加多样性具有一些优势。多项研究通过显示遗传多样性与群体适应度之间的正相关关系，以及发现多样性的实验操纵对群体表现的影响，支持了这一假说。然而，大多数这些报告可能有其他解释，并且真社会性昆虫多样性对性能的影响仍有待验证。在这项研究中，我们在小型黑蚁（Lasius niger）群体中实验性地增加了工蚁的多样性，同时控制了典型的混杂因素。
我们发现，由来自三个不同来源群体的工蚁组成的实验群体比由单个群体的工蚁组成的群体产生了更多的幼虫，并且大小变化也更多。
我们提出，多样性增加的好处源于劳动分工的改善。我们的研究证实，工蚁的多样性增强了群体的表现，从而为许多真社会性昆虫中多配偶女王和多女王群体的进化提供了一个可能的解释。
