Denic S, Nagelkerke N, Agarwal M M
Department of Internal Medicine, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
Public Health Genomics. 2011;14(3):162-8. doi: 10.1159/000321771. Epub 2010 Dec 10.
Consanguineous marriages, often viewed as incestuous and objectionable, are more widespread than commonly perceived. They integrate multiple facets of human adaptation: economic, cultural and genetic. The widely touted explanation for the origin and persistence of consanguinity is that it provides many socioeconomic benefits; however, this view may be too simplistic. The bias against consanguinity may preclude an objective understanding of this sociobiological puzzle. Inbreeding increases the speed of selection of beneficial recessive and co-dominant alleles, e.g. those that protect against diseases. In populations endemic with malaria, the prevalence of consanguineous marriages and the frequency of alleles protective against malaria are both very high. Thus, consanguinity could theoretically increase the relative fitness of a population under specific ecological conditions; sometimes, the overall genetic benefits may exceed genetic costs of inbreeding. We discuss some recent evidence from studies on inbreeding along with the reasons responsible for the mating strategy found in some human populations. We contend that a better appreciation of our inherent biases and potential genetic benefits of inbreeding in specific ecological conditions would help us to appreciate the wider picture of consanguinity.
近亲婚姻，常被视为乱伦且令人反感，其实际存在范围比普遍认知的更为广泛。它融合了人类适应的多个方面：经济、文化和基因。对于近亲关系起源与持续存在的普遍解释是，它带来诸多社会经济益处；然而，这种观点可能过于简单化。对近亲关系的偏见可能阻碍对这一社会生物学谜题的客观理解。近亲繁殖会加快有益隐性和共显性等位基因（例如那些预防疾病的等位基因）的选择速度。在疟疾流行的人群中，近亲婚姻的比例以及对抗疟疾等位基因的频率都非常高。因此，在特定生态条件下，近亲关系理论上可以提高一个群体的相对适应性；有时，整体的基因益处可能超过近亲繁殖的基因成本。我们讨论了一些近期关于近亲繁殖研究的证据，以及在某些人类群体中发现的这种交配策略背后的原因。我们认为，更好地认识我们固有的偏见以及近亲繁殖在特定生态条件下潜在的基因益处，将有助于我们更全面地理解近亲关系。
