Guermazi Dorra, Saliba Elie
Department of Dermatology, Warren Alpert Medical School of Brown University, Providence, RI 02903, USA.
Department of Dermatology, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut 13-5053, Lebanon.
Biology (Basel). 2025 Aug 10;14(8):1026. doi: 10.3390/biology14081026.
Human skin pigmentation is one of the most visible and variable traits among populations and has been shaped primarily by natural selection in response to ultraviolet (UV) radiation. This review synthesizes the current understanding of the genetic and evolutionary mechanisms that underlie pigmentation differences across the globe. The roles of key pigmentation-related genes, such as MC1R, SLC24A5, TYR, and OCA2, are examined in terms of how different versions of these genes have been favored in different UV environments to balance the need for photoprotection and vitamin-D synthesis. Evidence of convergent evolution in lighter skin pigmentation is explored among populations in Europe and East Asia, along with the relatively stable presence of darker pigmentation alleles in equatorial regions. We also highlight how recent research has integrated ecological, anthropological, and genomic data to paint a fuller picture of these adaptive patterns. Finally, we discuss the biomedical implications of these evolutionary processes, including how historical adaptations influence current differences in skin cancer risk, vitamin-D metabolism, and pigmentary disorders. By tracing the evolutionary history of skin color, this review emphasizes the intricate interplay between our genetics, environment, and health.
人类皮肤色素沉着是人群中最明显且具有多样性的特征之一，主要是由自然选择塑造的，以应对紫外线（UV）辐射。本综述综合了目前对全球色素沉着差异背后的遗传和进化机制的理解。研究了关键色素沉着相关基因的作用，如MC1R、SLC24A5、TYR和OCA2，探讨了这些基因的不同版本如何在不同的紫外线环境中受到青睐，以平衡光保护和维生素D合成的需求。探讨了欧洲和东亚人群中浅肤色色素沉着趋同进化的证据，以及赤道地区深色色素沉着等位基因相对稳定的存在情况。我们还强调了最近的研究如何整合生态、人类学和基因组数据，以更全面地描绘这些适应模式。最后，我们讨论了这些进化过程的生物医学意义，包括历史适应性如何影响当前皮肤癌风险、维生素D代谢和色素紊乱方面的差异。通过追溯肤色的进化历史，本综述强调了我们的基因、环境和健康之间复杂的相互作用。
