Does developmental plasticity direct the divergence among species?

发育可塑性是否直接影响物种间的分化？

• 批准号: 2383703
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2383703
• 关键词: Does; developmental; plasticity; direct; divergence

Selection pressure is determined by ecological opportunity, but the response to selection depends on individual form (1). Individual form matters because individuals in species are characterised by a distinctive set of codependent traits. Selection on one trait can therefore generate a response to selection in others. This evolutionary constraint due to trait covariation is imposed by heredity or natural selection and can limit adaptation by channelling evolution in the direction of least evolutionary resistance (2) characterised by abundant phenotypic variability (3). Allometric relationships of size-shape covariance are classic lines of least evolutionary resistance. Allometries have been categorised into within-individual, among-individual and among-species scales (reviewed by 4), making them an ideal framework to investigate how variation among individuals generates variation among species.Contradicting recent re-analyses of over 300 animal taxa (5,6), Brombacher, Ezard et al. (invited resubmission, American Naturalist) found a decoupling between among-individual and among-species allometries in 12,633 individuals of two- species of planktonic foraminifera exposed to the intensification of Northern Hemisphere glaciation during the Pliocene. Neither published study (5,6) sampled through a major climate transition. The generality of when among-individual and among-species allometries become decoupled, as well as the macroevolutionary consequences of this decoupling are testable with PISTON's data from WP2, WP4 and WP5 for the first time.Our overarching hypothesis for PhD1 is that within-individual changes catalyse the breakdown in among-individual and among-species allometries. This question is one of the oldest in evolutionary biology: von Baer's third law states that individuals in different species become increasingly dissimilar from one each other during development, implying we should see changes at the within-individual level before species diverge. In reality, variation among individuals is a dynamic force that represents the ghost of evolution past. Under supervision of Watson and Ezard, PhD1 will extend well-developed learning theory models, familiar in computer science, to formally characterise how the cumulative outcome of historical selection facilitates future adaptability (7). Watson's existing theoretical models find that developmental correlations will align with directional selection creating 'lines of least resistance' (2) that facilitate directional adaptive change (7,8). This PhD project will extend learning theory with adaptive dynamics models (9) parameterised by foraminiferal trait distributions and environmental reconstructions to address three overarching questions:1: Does within-species plasticity precede and direct divergence among species along lines of least evolutionary resistance? 2: Are certain parts of the life-course (e.g., a developmental window early in life prior to canalisation) more predictive of divergence among species than others?3: How do historical environmental change and intraspecific variation interact to determine whether the allometric relationships will break down across individual, population and species scales?References: (1) Lande & Arnold 1983 Evolution 37, 1210. (2) Schluter 1996 J. Evol. Biol. 50, 1766. (3) Hunt 2007 Evolution 61, 1560. (4) Pelabon et al. 2014 Ann. New York Acad. Sci. 1320, 58. (5) Voje et al. 2014 Evolution 68, 866. (6) Firmat et al. 2014 Phil. Trans. R. Soc. B 369, 20140057. (7) Watson & Szathmary 2016 Trends Ecol. Evol. 31, 147. (8) Watson et al. 2014 Evolution 68, 1124. (9) Doebeli & Dieckmann (2000). Amer. Nat. 156, S77.

选择压力由生态机会决定，但对选择的反应取决于个体形式(1)。个体形式很重要，因为物种中的个体具有一套独特的相互依存的特征。因此，对一个性状的选择可以对其他性状的选择产生反应。这种由性状协变造成的进化约束是由遗传或自然选择强加的，并可能通过引导进化朝着进化阻力最小的方向进行限制适应(2)以丰富的表型变异为特征(3)。大小-形状协方差的异速生长关系是进化阻力最小的经典品系。等位测量学被归类为个体内、个体间和物种间的尺度(综述4)，使它们成为研究个体之间的差异如何产生物种间差异的理想框架。对比最近对300多个动物分类群的重新分析(5，6)，Brombacher，Ezard等人。(受邀重新提交，美国博物学家)在上新世暴露于北半球冰川加剧的两种浮游有孔虫的12,633个个体中，发现个体间和物种间的异速生长之间存在脱钩现象。两项已发表的研究(5，6)都不是通过重大气候变化进行抽样的。当个体间和物种间的异速生长变得解耦时的普遍性，以及这种解耦的宏观进化后果首次可以用来自WP2，WP4和WP5的活塞数据进行检验。我们对PhD1的总体假设是，个体内的变化催化了个体间和物种间的异速生长的分解。这个问题是进化生物学中最古老的问题之一：冯·贝尔第三定律指出，不同物种的个体在发育过程中彼此之间的差异越来越大，这意味着我们应该在物种分化之前看到个体内部水平的变化。事实上，个体之间的差异是一种动态的力量，代表着进化过去的幽灵。在Watson和Ezard的监督下，博士1将扩展计算机科学中熟悉的成熟的学习理论模型，以正式描述历史选择的累积结果如何促进未来的适应性(7)。沃森现有的理论模型发现，发展相关性将与方向性选择保持一致，创造出阻力最小的线(2)，从而促进方向性适应变化(7，8)。这个博士项目将用由有孔虫特征分布和环境重建参数化的自适应动力学模型(9)来扩展学习理论，以解决三个首要问题：1：物种内的可塑性是否先于物种之间的差异，并沿着进化阻力最小的路线引导物种之间的差异？2：生命过程的某些部分(例如，在开化之前的早期生命的发育窗口)是否比其他部分更能预测物种之间的差异？3：历史环境变化和种内变化如何相互作用，以确定异速生长关系是否会在个体、种群和物种尺度上崩溃？参考文献：(1)Lande&Arnold 1983，进化37,1210。(2)Schluter 1996 J.Evol.比奥尔。50年，1766年。(3)《狩猎2007》《进化》61,1560。(4)Pelabon等人。2014安。纽约阿卡德。SCI。1320，58。(5)Voje等人。2014年进化论68,866。(6)Firmat等人。2014年菲尔。翻译过来的。R.Soc.B 369,20140057。(注：7)Watson&Szathary 2016 Trends Ecol.埃沃尔。31,147。(8)Watson等人。2014年进化论68,1124。(9)Doebeli&Dieckmann(2000)。阿默。纳特。156，第77条。