Dissertation Research: Evolution of Host Affiliation in an Ant-Plant Mutualism: Phylogeny of the Crematogaster Inhabitants of Macaranga (Euphorbiaceae).

在东南亚的季节性雨林中，Crematogaster属的蚂蚁只生活在血桐属（大戟科）的树干内，形成了一种双方都受益的专性伙伴关系。蚂蚁将藤蔓和食草动物从宿主身上移走，只靠植物产生的食物和它们在茎内照料的介壳虫的蜜露为生。相互作用涉及CA。8个蚂蚁谱系和CA。26种寄主。基于一个分子系统发育的火葬，我们将调查其与血桐宿主的进化趋势。特别是，我们将研究主机性状和蚂蚁性状之间的相关性，影响关联模式。初步结果表明，是否存在丰富的上表皮蜡花的茎上的血桐发挥了重要作用，在确定的身份的蚂蚁租户血桐。我们的目标也是解决一些机制，在主机协会的系统发育模式的基础上，例如，什么是当代和历史过程中的相对贡献，在解释模式的协会？此外，使用分子生物学和扫描电子显微镜，我们试图解决蚂蚁的物种限制所建议的形态数据。因为我们的结论的完整性取决于假设的Macaranga栖息的蚂蚁形成一个自然组，我们将验证单系的蚂蚁，包括在分子系统发育的其他成员，他们的亚属没有发现与Macaranga。血桐的生态学、系统学和植物地理学已经被彻底研究，提供了一个比仅仅基于蚂蚁的调查更全面的系统理解。我们的研究的遗传学的全面范围将为越来越多的关于这种相互作用的生态方面的研究提供一个进化的视角。这项研究将为其他基于遗传学的蚂蚁-植物研究提供比较，并有助于阐明蚂蚁-植物互惠关系中的生态和进化主题。与共生系统中的共生体是直接从上一代继承（如丝兰和丝兰蛾，无花果和无花果黄蜂）的对比可能揭示了为什么共同物种形成更经常解释授粉互惠的进化比它没有蚂蚁植物互惠。

In the aseasonal rain forests of Southeast Asia, ants of the genus Crematogaster live exclusively inside stems of trees in the genus Macaranga (Euphorbiaceae), forming an obligate partnership from which both parties benefit. The ants remove vines and herbivores from their hosts and subsist exclusively on food bodies produced by the plants and honey-dew from scale-insect which they tend inside the stems. The interaction involves ca. 8 ant lineages and ca. 26 host species. Based on a molecular phylogeny of the Crematogaster, we will investigate evolutionary trends in their association with Macaranga hosts. In particular we will examine correlations between host traits and ant traits that influence patterns of association. Preliminary results indicate that the presence or absence of copious epicuticular wax blooms on the stems of Macaranga have played an important role in determining the identity of the ant tenants on Macaranga. We also aim to address some of the mechanisms that underlie the phylogenetic patterns in host association, for example, what are the relative contributions of contemporary and historical processes in explaining patterns of association? Additionally, using the molecular phylogeny and Scanning Electron Microscopy, we seek to resolve species limits in the ants as suggested by morphological data. Because the integrity of our conclusions are contingent upon the assumption that the Macaranga-inhabiting ants form a natural group, we will verify the monophyly of the ants by including in the molecular phylogeny other members of their subgenus not found with Macaranga. The ecology, systematics and biogeography of Macaranga have been thoroughly investigated, affording a more holistic understanding of the system beyond an investigation based solely on the ants.The phylogenetically comprehensive scope of our study will afford an evolutionary perspective to the growing body of research on the ecological aspects of this interaction. This study will provide a comparison for other phylogenetically-based ant-plant studies and help illuminate ecological and evolutionary themes in ant-plant mutualisms. Contrasts with mutualistic systems where symbionts are directly inherited from the previous generation (such as yucca and yucca moths, and figs and fig wasps) may reveal why cospeciation more often explains the evolution of pollinating mutualisms than it does ant-plant mutualisms.