The evolutionary significance of intra- and intercolonial variation in behavior, morphology, genetics and immuno-competence in ants

与差异繁殖有关的性状的变异和遗传力总是导致自然选择，从而导致进化。然而，对于许多物种来说，关于特定特征的自然选择的方向和力度在很大程度上是未知的。我们将通过估计蚂蚁行为(攻击性、探索性、社会行为的标准化测试)、工蚁体型、杂合度、遗传多样性和免疫能力等性状的选择梯度，来调查哪些性状在野外被选择。在群居昆虫中，不仅意味着特征值在独立的进化单位--群体--之间可能不同，而且特征上的变异也是如此。分工被认为是昆虫群落在生态上取得成功的主要原因，我们将测试筑巢伙伴之间的行为、遗传、免疫和形态变异如何与群体生产力相关。如果强大的分工是适应性的，那么行为变异更强的蚂蚁群体将会更有生产力。初步研究表明，群体在形态和行为上一直存在差异，群体内的行为差异与适合度相关的人均生产率有关。然而，我们也可以展示环境对蚂蚁行为的影响，例如，蚂蚁群体的攻击性随着当地巢穴密度和社会寄生虫接触的增加而增加。因此，我们的目标是确定自然选择(作用于行为背后的基因)和行为可塑性(对生态条件的反应)如何影响蚂蚁的行为。

Variation and heritability of traits connected to differential reproduction invariably leads to natural selection and hence to evolution. Yet, for many species the direction and strength of natural selection on specific traits is largely unknown. We will investigate which traits of Temnothorax ants are under selection in the field by estimating selection gradients on traits such as ant behavior (standardized tests of aggression, explorative, social behaviors), worker body size, heterozygosity, genetic diversity and immune-competence via trait-fitness regressions. In social insects, not only mean trait values can vary between independent evolutionary units – the colonies – but also variation in traits. Division of labor has been recognized as a primary cause for the ecological success of insect societies and we will test how behavioral, genetic, immunological and morphological variation among nest mates is associated with colony productivity. If a strong division of labor is adaptive, then ant colonies with stronger variation in behavior will be more productive. Preliminary studies demonstrate that colonies consistently vary in morphology and behavior and that within-colony behavioral variation is associated with a fitness correlate – per-capita-productivity. However, we could also show environmental influences on ant behavior, e.g. aggression of ant colonies increased with local nest density and social parasite contact. We therefore aim to identify how natural selection (acting on genes underlying behavior) and behavioral plasticity (a response to ecological conditions) influence ant behavior.