Department of Biological Sciences, University of Hull, Cottingham Road, Hull HU67RX, UK.
Proc Biol Sci. 2009 Dec 22;276(1677):4423-31. doi: 10.1098/rspb.2009.1408. Epub 2009 Sep 30.
Identifying species exhibiting variation in social organization is an important step towards explaining the genetic and environmental factors underlying social evolution. In most studied populations of the ant Leptothorax acervorum, reproduction is shared among queens in multiple queen colonies (polygyny). By contrast, reports from other populations, but based on weaker evidence, suggest a single queen may monopolize all reproduction in multiple queen colonies (functional monogyny). Here we identify a marked polymorphism in social organization in this species, by conclusively showing that functional monogyny is exhibited in a Spanish population, showing that the social organization is stable and not purely a consequence of daughter queens overwintering, that daughter queen re-adoption is frequent and queen turnover is low. Importantly, we show that polygynous and functionally monogynous populations are not genetically distinct from one another based on mtDNA and nDNA. This suggests a recent evolutionary divergence between social phenotypes. Finally, when functionally monogynous and polygynous colonies were kept under identical laboratory conditions, social organization did not change, suggesting a genetic basis for the polymorphism. We discuss the implications of these findings to the study of reproductive skew.
确定表现出社会组织变异的物种是解释社会进化背后的遗传和环境因素的重要步骤。在研究最多的 Leptothorax acervorum 蚂蚁种群中，繁殖是由多个女王群体中的女王共同进行的（多雌多雄制）。相比之下，来自其他种群的报告，但基于较弱的证据，表明一个女王可能垄断多个女王群体中的所有繁殖（功能性单雌多雄制）。在这里，我们通过确凿地证明西班牙种群中存在功能性单雌多雄制，确定了该物种在社会组织方面存在明显的多态性，表明这种社会组织是稳定的，并非仅仅是由于女王幼虫越冬造成的，女王幼虫的再收养很常见，女王更替率低。重要的是，我们表明，基于 mtDNA 和 nDNA，多雌多雄制和功能性单雌多雄制种群彼此之间没有遗传上的区别。这表明社会表型之间存在最近的进化分歧。最后，当功能性单雌多雄制和多雌多雄制群体在相同的实验室条件下饲养时，社会组织没有发生变化，这表明多态性存在遗传基础。我们讨论了这些发现对生殖倾斜研究的意义。
