Blumenfeld Alexander J, Eyer Pierre-André, Helms Anjel M, Buczkowski Grzegorz, Vargo Edward L
Department of Entomology, TAMU, Texas A&M University, College Station, Texas, USA.
Department of Entomology, Purdue University, West Lafayette, Indiana, USA.
Mol Ecol. 2022 Sep;31(18):4832-4850. doi: 10.1111/mec.16188. Epub 2021 Oct 5.
Biological invasions are becoming more prevalent due to the rise of global trade and expansion of urban areas. Ants are among the most prolific invaders with many exhibiting a multiqueen colony structure, dependent colony foundation and reduced internest aggression. Although these characteristics are generally associated with the invasions of exotic ants, they may also facilitate the spread of native ants into novel habitats. Native to diverse habitats across North America, the odorous house ant Tapinoma sessile has become abundant in urban environments throughout the United States. Natural colonies typically have a small workforce, inhabit a single nest, and are headed by a single queen, whereas urban colonies tend to be several orders of magnitude larger, inhabit multiple nests (i.e., polydomy) and are headed by multiple queens (i.e., polygyny). Here, we explore and compare the population genetic and breeding structure of T. sessile within and between urban and natural environments in several localities across its distribution range. We found the social structure of a colony to be a plastic trait in both habitats, although extreme polygyny was confined to urban habitats. Additionally, polydomous colonies were only present in urban habitats, suggesting T. sessile can only achieve supercoloniality within urbanized areas. Finally, we identified strong differentiation between urban and natural populations in each locality and continent-wide, indicating cities may restrict gene flow and exert intense selection pressure. Overall, our study highlights urbanization's influence in charting the evolutionary course for species.
由于全球贸易的兴起和城市地区的扩张，生物入侵正变得越来越普遍。蚂蚁是最多产的入侵者之一，许多蚂蚁表现出多蚁后群体结构、依赖群体建立以及减少巢间攻击。尽管这些特征通常与外来蚂蚁的入侵有关，但它们也可能促进本地蚂蚁扩散到新的栖息地。臭家蚁（Tapinoma sessile）原产于北美各地的不同栖息地，在美国各地的城市环境中已大量存在。自然群体通常劳动力较少，栖息在单个巢穴中，由单个蚁后领导，而城市群体往往要大几个数量级，栖息在多个巢穴中（即多巢居），并由多个蚁后领导（即多雌型）。在这里，我们探索并比较了臭家蚁在其分布范围内几个地点的城市和自然环境内部以及之间的种群遗传和繁殖结构。我们发现，在这两种栖息地中，群体的社会结构都是一种可塑性特征，尽管极端多雌型仅限于城市栖息地。此外，多巢居群体只存在于城市栖息地，这表明臭家蚁只能在城市化地区实现超级群体化。最后，我们在每个地点以及整个大陆范围内都发现了城市和自然种群之间的强烈分化，这表明城市可能会限制基因流动并施加强烈的选择压力。总体而言，我们的研究突出了城市化在描绘物种进化进程方面的影响。
