NEW APPROACHES TO THE MODELING OF SPECIATION

该项目的总体目标是更好地了解生物学 通过对动态和静态的研究， 各种多位点模型的行为。现有的建模方法 在几个方面都有缺陷。通常是一个小数目（一个 或两个）的基因座或数量性状，选择被认为是 要想弱，人口规模被认为是恒定的，只有一个非常 数量有限的选择制度主要反映了占主导地位的 “崎岖的适应性景观”的范例进行了研究。最近一个新的 “多孔适应性景观”的比喻（Gavrilets和Gravner，1997年） 作为一个合理的替代传统的观点， 崎岖的适应性景观。这个比喻，可以追溯到两个- 由Dobzhansky（1937）描述的基因座双等位基因模型，是基因组遗传学的核心。 这里提出的研究。 使用分析方法和广泛的数值计算相结合， 模拟这个项目将研究多孔物种形成的动力学 适应性景观，考虑到各种因素， 自然人口。在开发和分析物种形成模型时， 标准群体遗传学方法和新方法 将使用物理学中开发的。 本项目将研究多孔适应性景观的结构 通过关注相关的景观， 遗传分化和物种形成的可能性， 重组多孔自适应种群演化动力学 由突变、分离和重组所决定的景观， 随机和非随机交配、空间分布、种群增长和 将研究随机漂移。理论假设和预测将 对自然种群和实验室种群的特性进行测试。为 这个目的，杂交和回交中的适合度分布， 实验室种群对人工选择的反应， 混合带特征及宏观演化模式 化石记录中的信息。

The overall aim of this project is to better understand biological processes leading to speciation 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 (one or two) of loci or quantitative traits are considered, selectin 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 hew metaphor of "holey adaptive landscapes" (Gavrilets and Gravner, 1997) has been put forward as a plausible alternative to the conventional view of rugged adaptive landscapes. This metaphor, which can be traced to a two- locus two-allele model described by Dobzhansky (1937), is the core of the research proposed here. Using a combination of analytical methods and extensive numerical simulations this project will study the dynamics of speciation of holey adaptive landscapes taking into account various factors operating in natural populations. In developing and analyzing speciation models both standard population genetics approaches and novel methods recently developed in physics will be used. This project will investigate the structure of holey adaptive landscapes by focusing on correlated landscapes and concentrating on the possibilities for genetic divergence and speciation introduced by recombination. The dynamics of population evolution on holey adaptive landscapes as determined by mutation, segregation and recombination, random and non-random mating, spatial distribution, population growth and random drift will be studied. Theoretical assumptions and predictions will be tested against properties of natural and laboratory populations. For this purpose, distributions of fitnesses in hybrids and backcrosses, responses of laboratory populations to artificial selection, characteristics of hybrid zones, and macroevolutionary patterns deduced from the fossil record will be used.