Fitness landscapes and adaptive dynamics

在突变和选择的影响下，种群的适应性进化是由底层适应度景观的结构决定的。在这里，适合度可以直接分配给基因型，或者它动态地从生态相互作用中产生。在第一种情况下thefitness景观被建模为基因型空间上的随机函数，并且兴趣在于表征高fitnessregions的进化可访问性，例如，在上升的健身路径和uphilladaptive walks的属性方面。在第一个资助期取得的成果的基础上，该项目将继续调查相关表型类别的可访问性，并引入更现实的模型，包括明确的中间表型。还将开发用于探索高维经验数据集的自适应行走的应用。在第一个供资期内，适应性动态研究的一项重要成就是严格控制了各种尺度限制，现在可以利用这些结果为基于个人的生态动态的简化适应性步行模型提供基础。此外，分析将扩展到制度的进化分支，更高的突变率和二倍体重组的遗传多样性的影响将得到解决。该项目的进一步重点将是在肿瘤生长和免疫治疗的背景下出现的表型转换的自适应动力学模型。

The adaptive evolution of a population under the influenceof mutation and selection is governed by the structure of theunderlying fitness landscape. Here fitness can either be assigned directly to genotypes, or it arises dynamically from ecological interactions. In the first case thefitness landscape is modeled as a random function on the space of genotypes, andthe interest is in characterizing the evolutionary accessibility of high-fitnessregions, for example, in terms of pathways of ascending fitness and the properties of uphilladaptive walks. Building on results achieved in the first funding period, the project willcontinue the investigation of accessibility properties for classes of correlated landscapesand introduce more realistic models incorporating explicit intermediate phenotypes. The application of adaptive walks for the exploration of high-dimensional empirical data sets will also be developed. An important achievement of the investigation of adaptive dynamics in the first funding period was a rigorous control of various scaling limits, and these results can now be exploited to provide an underpinning of the simplified adaptive walk models in terms of individual-based ecological dynamics. Moreover, the analysis will be extended to the regime of evolutionary branching, and the effects of higher mutation rates and diploid recombination on genetic diversity will be addressed. A further focus of the project will be on adaptive dynamics models with phenotypic switchingthat arise in the context of tumor growth and immunotherapy.