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Identifying Regions of the Human Genome that Exhibit Evidence of Positive Selection

  1. Ryosuke Kimura1,
  2. Jun Ohashi2

Published Online: 15 NOV 2013

DOI: 10.1002/9780470015902.a0020850.pub2

eLS

eLS

How to Cite

Kimura, R. and Ohashi, J. 2013. Identifying Regions of the Human Genome that Exhibit Evidence of Positive Selection. eLS. .

Author Information

  1. 1

    University of the Ryukyus, Nishihara, Japan

  2. 2

    University of Tsukuba, Tsukuba, Japan

Publication History

  1. Published Online: 15 NOV 2013

Abstract

The recent availability of genomic data from humans has driven genome-wide scans for natural selection; these scans use several approaches based on comparative genetics and population genetics. Such studies have identified many possible occurrences of positive selection in the human genome, but the results should be interpreted with caution because false positives are unavoidable. Here, we review approaches for identifying positive selection in the human genome, and explain in detail an approach designed to detect recent positive selection; this approach is based on haplotype variation and linkage disequilibrium. Signatures of positive selection in the human genome offer clues on how biological features of humans have evolved and on how humans have genetically adapted to their environments and own lifestyles – including climate, diet and pathogens.

Key Concepts:

  • Comparative genetics approaches identify human-specific constraint or accelerated gene evolution, but have a methodological limitation.

  • Population genetics approaches based on haplotype variation effectively detect recent positive selection.

  • Genome-wide scans for selection have identified a number of candidate loci; these findings enable us to reconstruct the history of human genetic adaptation.

  • The results of scans for selection have to be interpreted with caution since the occurrence of false positives and false negatives is inevitable.

  • Further improvements in statistical analysis and establishment of functional analysis are required for future studies to validate variants associated with adaptive phenotypes.

Keywords:

  • natural selection;
  • genetic adaptation;
  • human genome;
  • genetic diversity;
  • selective sweep;
  • haplotype variation;
  • phenotypic difference;
  • selective pressure