NEW APPROACHES TO THE MODELING OF SPECIATION

形态建模的新方法

• 批准号: 6285073
• 负责人: SERGEY Y GAVRILETS
• 金额: $ 15.24万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6285073
• 关键词: analytical method; biochemical evolution; computer simulation; genetic models; genetic polymorphism; genetic recombination; genotype; mathematical model; natural selections; physical fitness; population genetics; quantitative trait loci; species difference; systematic biology

The overall aim of this project is to better understand biological processes leading to speciation and diversification through a study of the dynamic and static behavior of various multilocus models. Existing approaches to the modeling of speciation are deficient in several ways. Usually a small number of loci or quantitative traits are considered, selection is assumed to be weak, population size is considered to be constant, and only a very limited number of selection regimes mostly reflecting the dominant paradigm of "rugged adaptive landscapes" have been studied. Recently a new metaphor of "holey adaptive landscapes" (Gavrilets 1997) has been put forward as a plausible alternative to the conventional view of rugged adaptive landscapes. This metaphor is the core of the research proposed here. This project will investigate: (i) dynamics of genetic and morphological diversification in (growing) populations and clades, (ii) evolutionary dynamics of metapopulations and hybrid zones, (iii) coevolutionary dynamics. The biological questions to be approached here are very diverse. However, there is a unifying theme underlying the methods to be used. This theme is that biological organisms can be viewed as very long sequences with thousands and millions elements (e.g. genes or DNA base pairs). Thus, from a mathematical point of view, biological evolution takes place in a space with an enormous number of dimensions. Consequently, a significant proportion of evolutionary changes are expected to happen along nearly neutral networks and on holey adaptive landscapes. Chance and contingency should play a major role in evolutionary dynamics. Here, a combination of analytical methods recently developed in theoretical evolutionary biology, mathematics, and physics and extensive numerical simulations will be used to take into account various factors operating in natural populations (selection, mutation, recombination, random drift, migration, extinction, colonization etc).

该项目的总体目标是通过研究各种多位点模型的动态和静态行为，更好地了解导致物种形成和多样化的生物过程。现有的物种形成建模方法在几个方面存在缺陷。通常考虑少量的基因座或数量性状，假设选择很弱，种群规模被认为是恒定的，并且只研究了非常有限数量的选择机制，这些选择机制主要反映了“崎岖的适应性景观”的主导范式。最近，“多孔适应性景观”（Gavrilets 1997）的新隐喻被提出，作为崎岖适应性景观传统观点的合理替代。这个比喻是这里提出的研究的核心。该项目将研究：（i）（增长的）种群和分支的遗传和形态多样化动态，（ii）集合种群和杂交区的进化动态，（iii）共同进化动态。这里要解决的生物学问题非常多样化。然而，所使用的方法背后有一个统一的主题。这个主题是生物有机体可以被视为具有成千上万个元素（例如基因或 DNA 碱基对）的非常长的序列。因此，从数学的角度来看，生物进化发生在一个具有大量维度的空间中。因此，预计进化变化的很大一部分将发生在近乎中性的网络和多孔的适应性景观上。机会和偶然性应该在进化动力学中发挥重要作用。在这里，将结合最近在理论进化生物学、数学和物理学领域开发的分析方法以及广泛的数值模拟来考虑自然种群中运作的各种因素（选择、突变、重组、随机漂移、迁移、灭绝、殖民等）。