Adaptive evolution across multi-scale biological systems: finding a bridge between molecular evolution and multi-species dynamics.

跨多尺度生物系统的适应性进化：寻找分子进化和多物种动力学之间的桥梁。

• 批准号: RGPIN-2020-04109
• 负责人: Bielawski, Joseph
• 金额: $ 2.91万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716359
• 关键词: Adaptive; evolution; across; multi; scale

Genes exist within species, species exist within communities, and communities exist within ecosystems. Consider the emergent complexity of a multi-species community; it is a self-organizing system shaped by the combined activities of its species, with the information required for those activities stored at “lower levels” within genes. The biological activities occurring inside of the species, or the community, can manifest externally (e.g., changing the ecosystem), and thereby influence the properties and dynamics of the community itself. The key insight here is that the fitness landscape that genes “perceive” cannot be independent of how those genes affect higher levels of complexity. Therefore a complex biological system (e.g., a community) can develop a complex network of causal interactions over evolutionary time, with feedback between levels (e.g., genes, species and community) influencing each gene's adaptive landscape. However, the classical account of adaptive gene evolution, as embodied by neo-Darwinian theory, is reductionist and largely assumes unidirectional causal pathways. Thus, the classical approach has struggled to provide a full account of how evolution can establish and fine-tune links within multi-scale biological systems. Such multi-level causality motivated the highly-regarded philosopher of biology, Evelyn Fox Keller, to question the way biologists use the concept of “the gene for” to explain complex biological systems. If Evelyn Fox Keller is correct, then fundamental questions about the origin and evolution of complexity cannot be solved if we persist in pursuing purely reductive explanations. Indeed, Keller has recently called on biologists to adapt their analysis and modelling techniques to address multi-scale systems, and to consider a “pluralistic mosaic” of different strategies. The proposed research program is a response to Keller's call from my perspective as an evolutionary biologist. Fundamental questions about biological complexity, such as those surrounding adaptive evolution across multi-scale systems, have fallen through the cracks of investigation because they lie on the boundary of two or more fields. The traditional approach to adaptive gene evolution is firmly rooted in population genetic theory and, while necessary, its scope is limited by a highly reductive view of adaptive landscapes. A complete understanding of adaptive evolution will require us to consider (i) the effect of multi-scale dynamics (e.g., multi-gene and multi-species interactions) on adaptive landscapes, (ii) a de-centralized mapping of genotype and phenotype, and (iii) multiple fields of biology. Because we are asking new questions, we will need to develop new research tools. Hence, this project seeks to develop theory and methods appropriate for understanding adaptive dynamics of genes (and genomes) across multi-scale biological systems. Trainees will acquire data science and genomics skills suitable to a broad the range of careers.

基因存在于物种中，物种存在于群落中，群落存在于生态系统中。想想一个多物种群落出现的复杂性；它是一个由其物种的组合活动形成的自组织系统，这些活动所需的信息存储在基因的“较低水平”。发生在物种或群落内部的生物活动可以在外部表现出来（例如，改变生态系统），从而影响群落本身的特性和动态。这里的关键观点是，基因“感知”的适应性景观不能独立于这些基因如何影响更高层次的复杂性。因此，一个复杂的生物系统（如群落）可以在进化过程中发展出一个复杂的因果相互作用网络，并在影响每个基因适应景观的水平（如基因、物种和群落）之间产生反馈。然而，适应性基因进化的经典解释，如新达尔文理论所体现的，是简化主义的，并且在很大程度上假设了单向的因果途径。因此，经典的方法一直在努力提供一个关于进化如何在多尺度生物系统中建立和微调联系的完整解释。这种多层次的因果关系促使备受尊敬的生物学哲学家伊芙琳·福克斯·凯勒（Evelyn Fox Keller）质疑生物学家使用“基因用于”这一概念来解释复杂生物系统的方式。如果伊夫林·福克斯·凯勒是正确的，那么如果我们坚持追求纯粹的简化解释，那么关于复杂性的起源和演化的基本问题就无法解决。事实上，凯勒最近呼吁生物学家调整他们的分析和建模技术，以解决多尺度系统，并考虑不同策略的“多元马赛克”。从我作为进化生物学家的角度来看，拟议的研究计划是对凯勒呼吁的回应。