Corballis Michael C
Department of Psychology, University of Auckland, Auckland, New Zealand.
Ann N Y Acad Sci. 2009 Mar;1156:19-43. doi: 10.1111/j.1749-6632.2009.04423.x.
Language, whether spoken or signed, can be viewed as a gestural system, evolving from the so-called mirror system in the primate brain. In nonhuman primates the gestural system is well developed for the productions and perception of manual action, especially transitive acts involving the grasping of objects. The emergence of bipedalism in the hominins freed the hands for the adaptation of the mirror system for intransitive acts for communication, initially through the miming of events. With the emergence of the genus Homo from some 2 million years ago, pressures for more complex communication and increased vocabulary size led to the conventionalization of gestures, the loss of iconic representation, and a gradual shift to vocal gestures replacing manual ones-although signed languages are still composed of manual and facial gestures. In parallel with the conventionalization of symbols, languages gained grammatical complexity, perhaps driven by the evolution of episodic memory and mental time travel, which involve combinations of familiar elements--Who did what to whom, when, where, and why? Language is thus adapted to allow us to share episodic structures, whether past, planned, or fictional, and so increase survival fitness.
语言，无论是口语还是手语，都可以被视为一种手势系统，它从灵长类大脑中所谓的镜像系统演化而来。在非人类灵长类动物中，手势系统在手部动作的产生和感知方面发展良好，尤其是涉及抓取物体的及物动作。人类两足行走的出现使双手得以解放，从而将镜像系统用于非及物动作的交流适应，最初是通过模仿事件来实现的。大约从200万年前智人属出现以来，更复杂交流和词汇量增加的压力导致了手势的常规化、象形表征的丧失，以及逐渐转向用语音手势取代手部手势——尽管手语仍然由手部和面部手势组成。与符号的常规化并行，语言在语法上变得更加复杂，这可能是由情景记忆和心理时间旅行的进化驱动的，情景记忆和心理时间旅行涉及熟悉元素的组合——谁在何时、何地、为何对谁做了什么？因此，语言得以适应，使我们能够分享情景结构，无论是过去的、计划中的还是虚构的，从而提高生存适应性。
