Evolution and diversification of ants

蚂蚁（膜翅目：蚁科）是生态上最成功的生物之一，有超过11,000种已知的20个亚科，起源于1.15 - 1.7亿年前。最近的研究提高了我们对这一群体进化关系的理解，使我们对蚂蚁社会结构、生活史和威胁的进化有了更深入的了解。尽管有这项研究，关于蚂蚁进化的基本问题仍然存在。这个博士项目使用系统发育比较方法来解决这个群体中基本的宏观进化和宏观生态问题。该学生将整理蚂蚁系统发育历史的数据，以产生第一个蚂蚁“超级树”，以及社会结构、生活史、地理分布和威胁的数据。这些数据将用于测试以下目标中的假设：目标1：量化超级树的多样化率变化，以确定主要的多样化变化何时发生在蚂蚁身上，以及哪些分类群对此负有特别责任。我们将使用不完整树来验证以下假设：(1)更完整的系统发育不会改变先前研究中在蚂蚁中检测到的60-100 MYA的多样化转变；(2)物种丰富的蚂蚁亚科（例如，Myrmicinae， Formicinae和Dolichoderinae）在多样化速率上经历了显著的独立转变，而这种转变独立于系统发育其他部分的多样化速率转变。目标2：量化导致已确定的多样化比率变化的因素。我们将检验以下假设：(3)与物种多样化相关的是等级分化的程度或性质。蚂蚁表现出大范围的等级结构，在蚁后和工蚁之间以及工蚁之间的形态分化程度都有所不同。这一假设认为，这种多样性与群落水平上的生态和进化成功相关，从而与物种多样化水平相关。目标3：确定蚂蚁空间生物多样性的分布和决定因素，以及如何最有效地优先考虑保护工作。我们将验证以下假设：(4)蚂蚁物种丰富度和受威胁物种丰富度的区域以及相关的生态和环境决定因素与其他群体相似；(5)当前保护区充分保护了蚂蚁物种丰富度和受威胁物种丰富度的“热点”；(6)边缘蚂蚁物种与IUCN确定的受威胁物种没有区别，并且当前IUCN排名充分保护了蚂蚁的进化史。关于假设6，蚂蚁是许多生态系统的基石物种，提供了许多基本的生态系统服务。通过了解决定它们分布的过程，我们可以为保护工作的重点提供优先级。我们将通过将IUCN排名与系统发育独特性相结合，为基于物种的保护工作提供新的优先事项，以创建适合当前zsl主导的优先计划的进化独特和全球濒危（EDGE）蚂蚁列表（www.edgeofexistence.org）。

Ants (Hymenoptera: Formicidae) are amongst the most ecologically successful organisms with over 11,000 known species in 20 subfamilies originating 115-170 million years ago. Recent work has advanced our understanding of the evolutionary relationships of this group, giving us a greater appreciation of the evolution of ant social structures, life histories and threats. Despite this research, fundamental questions about ant evolution remain. This PhD project uses phylogenetic comparative methods to address fundamental macroevolutionary and macroecological questions within this group. The student will collate data on ant phylogenetic histories to produce the first ant 'supertree', along with data on social structures, life histories, geographic distributions and threats. These data will be used to test the hypotheses within the following objectives: Objective 1: To quantify the diversification rate shifts in the supertree to identify when the major diversification shifts have occurred in ants and which taxa are particularly responsible. We will test the hypotheses that (1) a more complete phylogeny will not alter the diversification shift at 60-100 MYA detected in ants by a previous study using an incomplete tree, and (2) ant subfamilies which are species-rich (e.g., Myrmicinae, Formicinae and Dolichoderinae) have experienced significant independent shifts in diversification rate which are independent of diversification rate shifts in other parts of the phylogeny. Objective 2: To quantify the factors responsible for the diversification rate shifts identified. We will test the hypothesis that (3) a correlate of species diversification is the degree of, or nature of, caste differentiation. Ants show a large range of caste structures, with variation in the degree of morphological differentiation both between queen and workers and among workers. This hypothesis posits that such diversity is correlated with ecological and evolutionary success at the colony level and thence at the level of species diversification. Objective 3: To determine the distribution and determinants of ant spatial biodiversity and how to prioritise conservation effort most effectively. We will test the hypotheses that (4) areas of ant species-richness and threatened species-richness and associated ecological and environmental determinants are similar to those of other groups, (5) current protected areas adequately conserve ant species-richness and threatened species-richness 'hotspots', and (6) EDGE ant species are not different to those identified as threatened by IUCN, and current IUCN rankings adequately protect ant evolutionary history. As regards Hypothesis 6, ants are cornerstone species in many ecosystems providing a number of essential ecosystem services. By understanding the processes determining their distributions, we can provide priorities for where conservation effort should be focused. We will provide new priorities for species-based conservation efforts by combining IUCN rankings with phylogenetic distinctiveness to create a list of Evolutionary Distinct and Globally Endangered (EDGE) ants fitting into current ZSL-led priority schemes (www.edgeofexistence.org).