Data from: Non-nest mate discrimination and clonal colony structure in the parthenogenetic ant Cerapachys biroi

Understanding the interplay between cooperation and conflict in social groups is a major goal of biology. One important factor is genetic relatedness, and animal societies are usually composed of related but genetically different individuals, setting the stage for conflicts over reproductive allocation. Recently, however, it has been found that several ant species reproduce predominantly asexually. Although this can potentially give rise to clonal societies, in the few well-studied cases, colonies are often chimeric assemblies of different genotypes, due to worker drifting or colony fusion. In the ant Cerapachys biroi, queens are absent and all individuals reproduce via thelytokous parthenogenesis, making this species an ideal study system of asexual reproduction and its consequences for social dynamics. Here, we show that colonies in our study population on Okinawa, Japan, recognize and effectively discriminate against foreign workers, especially those from unrelated asexual lineages. In accord with this finding, colonies never contained more than a single asexual lineage and average pairwise genetic relatedness within colonies was extremely high (r = 0.99). This implies that the scope for social conflict in C. biroi is limited, with unusually high potential for cooperation and altruism.

解析社会群体中合作与冲突的相互作用机制，是生物学领域的核心研究目标之一。遗传相关性（genetic relatedness）是其中的关键影响因素之一；动物社会通常由亲缘相关但遗传背景各异的个体组成，这为生殖资源分配层面的冲突埋下了伏笔。不过近年来的研究发现，多个蚂蚁类群主要以无性生殖（asexual reproduction）方式繁衍后代。尽管该繁殖模式理论上可形成无性系社会（clonal societies），但在少数已被深入研究的案例中，由于工蚁漂移（worker drifting）或蚁群融合（colony fusion）现象，蚁群往往是不同基因型的嵌合集合体（chimeric assemblies）。在毕氏双针蚁（Cerapachys biroi）中，不存在蚁后，所有个体均通过产雌孤雌生殖（thelytokous parthenogenesis）繁衍后代，这使得该物种成为研究无性生殖及其对社会动态（social dynamics）影响的理想实验体系。本研究针对日本冲绳岛的毕氏双针蚁种群展开实验，结果显示，蚁群能够识别并有效区分外来工蚁，尤其是来自无亲缘关系无性系群（asexual lineages）的工蚁。这一发现与后续群体遗传学分析结果高度契合：该种群的蚁群仅包含单一无性系群，且蚁群内个体间的平均两两遗传相关性极高（r = 0.99）。这表明毕氏双针蚁的社会冲突空间极为有限，其合作与利他行为（altruism）具备极高的演化潜力。