Mechanisms of speciation

这项研究的目的是调查允许物种形成的条件，物种形成是生物物种多样性的唯一来源。本研究采用理论研究和实证研究相结合的方法，结合化石记录和分子系统学，构建了一个基于个体的性别选择基本模型，并对物种形成的可能性和条件进行了研究。我们研究了物种形成的可能性如何取决于男性性别特征和相关的女性偏好特征的分布。我们发现，物种形成事件的频率随着雄性和雌性性状的总体变异而增加，这取决于两个同种种群的隔离时间。这表明物种形成事件不受生态位宽度的限制，而是由于交配偏好的不同而是无限的。这一结果表明，一些群落中出现的异常物种多样性可能是由于性别选择的物种形成。我们在主要项目中对生物多样性和交配行为进行了许多扩展和相关研究：(1)多种物种的大规模模型与地理空间分布和长期环境波动(如冰期)的关系，(2)评价新物种稳定性和共存性的多物种稳定共存格子模型(草原群落模型)；(3)昆虫爬山行为的基于个体的交配行为模型及其模拟；(4)动物性别比的稳定性和季节性的定量分析。

The purpose of this study is to investigate the conditions that allows speciation that is the only source of species diversity of organisms. This study to scrutinize the speciation mechanisms is carried out by the theoretical studies and the empirical studies using fossil records and molecular phylogeny.Specifically, we build a basic individual-based model of sexual selection and studied the possibility and conditions of speciation. We examined how the likelihood of speciation depends on the distributions of a male sexual character and the associated female preference characters. We found that the frequency of speciation events increases with the overall variations in the male and female traits that depend on the duration of isolation of two conspecific populations. This indicates that the speciation events are not limited by ecological niche widths, rather it is unlimited due to the variation in mating preferences.This result suggests, that extraordinal species diversity seen in some communities, such as tropical forests and cichlid fishes in African lakes could be possible due to speciation by sexual selection.We carried out many extensions and related studies of biodiversity and mating behavior from the main project : (1) large-scale model of multiple speciations in relation to geographical spatial distributions and long-term environmental fluctuations (e.g., glacial periods), (2) the lattice model of stability and coexistence of many species (grassland community model) to evaluate the stability and coexistence of newly speciated species, (3) an individual-based mating behavior model of hilltopping behavior in insects and simulations, and (4) the quantitative analyses of stability and seasonality of animal sex ratios.