Balancing Selection in the Human Genome

摘要: Balancing selection maintains advantageous diversity in populations by a variety of mechanisms. As source for functional polymorphism, it contributes to the genetic and phenotypic present-day human populations. Classically, most our understanding influence balancing humans was based on few well-known examples, but recent advances at genome scale (made possible newly available genomic databases analytical methods) provide further insights targets humans. Such studies have pointed out uniqueness MHC locus, suggest that more typical cases exist. Our growing suggests although this is not pervasive force genome, has played role maintenance functionally relevant polymorphism humans. Key Concepts: Balancing populations. Different mechanisms constitute selection, all which maintain populations. Balancing humans, shaped evolution critical genes individual survival. The complex chromosome 6 shows striking, unique, signatures selection. Advantageous MHC-dependent antigen presentation patterns diverse loci. The can be identified both studying analysing genome-wide diversity. Genome-wide analyses are key identify previously unknown (and unsuspected) natural selection. Targets remain undiscovered genome. Keywords: balancing selection; population genomics; evolution; human evolution; genome; overdominance; heterosis; frequency-dependent selection; diversity; polymorphism