Llaurens V, Raymond M, Faurie C
Institut des Sciences de l'Evolution de Montpellier (UMR CNRS 5554), Université de Montpellier, Montpellier Cedex 5, France.
Philos Trans R Soc Lond B Biol Sci. 2009 Apr 12;364(1519):881-94. doi: 10.1098/rstb.2008.0235.
Since prehistoric times, left-handed individuals have been ubiquitous in human populations, exhibiting geographical frequency variations. Evolutionary explanations have been proposed for the persistence of the handedness polymorphism. Left-handedness could be favoured by negative frequency-dependent selection. Data have suggested that left-handedness, as the rare hand preference, could represent an important strategic advantage in fighting interactions. However, the fact that left-handedness occurs at a low frequency indicates that some evolutionary costs could be associated with left-handedness. Overall, the evolutionary dynamics of this polymorphism are not fully understood. Here, we review the abundant literature available regarding the possible mechanisms and consequences of left-handedness. We point out that hand preference is heritable, and report how hand preference is influenced by genetic, hormonal, developmental and cultural factors. We review the available information on potential fitness costs and benefits acting as selective forces on the proportion of left-handers. Thus, evolutionary perspectives on the persistence of this polymorphism in humans are gathered for the first time, highlighting the necessity for an assessment of fitness differences between right- and left-handers.
自史前时代以来，左撇子在人类群体中普遍存在，呈现出地理频率差异。人们针对用手习惯多态性的持续存在提出了进化方面的解释。左撇子可能受到负频率依赖选择的青睐。数据表明，作为罕见的用手偏好，左撇子在战斗互动中可能代表着一项重要的战略优势。然而，左撇子出现频率较低这一事实表明，左撇子可能伴随着一些进化成本。总体而言，这种多态性的进化动态尚未完全被理解。在此，我们回顾了关于左撇子可能的机制和后果的丰富文献。我们指出用手偏好是可遗传的，并报告了用手偏好是如何受到遗传、激素、发育和文化因素影响的。我们回顾了有关作为影响左撇子比例的选择力的潜在适应性成本和收益的现有信息。因此，首次收集了关于这种多态性在人类中持续存在的进化观点，强调了评估右撇子和左撇子之间适应性差异的必要性。
