中文摘要：

自然选择在词法特点的差异有一个关键角色。然而，位于词法特征的进化和差异下面的基因基础，特别地在上下文有机体行为，生活方式，和环境，很好没被理解。在哺乳动物的鼻音化学受体的发现提供了一个机会探讨这个问题。这里，我们识别 4 个鼻音化学受体基因家庭(V1R， V2R，或，并且 TAAR ) 从马，畿尼猪，狨和猩猩，染色体分别地定序。和以前描述的哺乳动物的鼻音化学受体基因全部剧目，我们发现了在功能的基因数字和词法复杂性之间的重要积极关联，两总体上嗅觉的系统和 vomeronasal 系统。词法数据，行为的数据，和基因全部剧目的联合分析建议夜的哺乳动物趋于拥有更种类特定的化学受体基因和更复杂的嗅觉的机关比日报哺乳动物。而且，进化力量的分析在种类特定的基因上揭示了积极选择的存在，多半反映气味和 pheromones 的种类特定的察觉。一起拿，这些结果在染色体规模反映改编的一个稀罕盒子到生理节奏的节奏活动，并且强烈建议词法嗅觉的机关的复杂性和在夜的哺乳动物的鼻音化学受体的多样化在为察觉夜的哺乳动物可以在他们的特别黑暗环境遇到的气味的变化的能力的选择下面。

英文摘要：

Natural selection has a critical role in the diversity of morphological traits. However, the genetic basis underlying the evolution and diversity of morphological characteristics, particularly in the context an organism＇s behavior, lifestyle, and environment, is not well understood. The discovery of nasal chemoreceptors in mammals provided an opportunity to address this question. Here, we identify 4 nasal chemoreceptor gene families （VIR, V2R, OR, and TAAR） from horse, guinea pig, marmoset and orangutan genome sequences, respectively. Together with previously described mammalian nasal chemoreceptor gene repertoires, we found a significant positive correlation between functional gene number and morphological complexity, both in the main olfactory system and the vomeronasal system. The combined analysis of morphological data, behavioral data, and gene repertoires suggests that nocturnal mammals tend to possess more species-specific chemoreceptor genes and more complicated olfactory organs than diurnal mammals. Moreover, analysis of evolutionary forces revealed the existence of positive selection on the species-specific genes, likely reflecting the species-specific detection of odors and pheromones. Taken together, these results reflect a rare case of adaptation to circadian rhythm activity at the genome scale, and strongly suggest that the complexity of morphological olfactory organs and the diversification of nasal chemoreceptors in nocturnal mammals are under selection for the ability to perceive the variety of odors that nocturnal mammals may encounter in their particular dark environments.