语言如何进化

How Language Evolved

人类语言具有复杂多变的递归结构，漫长的物种进化过程中唯独人类精通语言。语言的进化始于大约两百万年前的“更新世时期”，语言在当时作为一种认知适应对于人类应对自然界带给人类的挑战（如动物掠食与森林毁坏）有很大帮助。人类进化过程中学习与文化因素形成一种选择压力促使人际交流语法化，人际交流语法化引发大脑容量增加，然而，最初的语言进化与基因无关。学习与文化压力也使交流的媒介依次变为手语模式、表情模式与语言模式。交流媒介的逐渐变化最终导致了 FOXP2基因突变，FOXP2基因突变让智人具有了自主的言语能力。与地球上其它的人科动物相比，人类的语言能力使人类在进化中具有明显的优势。

Language， with its complex recursive structure， is almost certainly a uniquely human capacity. I argue that it evolved over the past 2 million years during the Pleistocene epoch， as part of a cognitive adaptation to deforestation and predation from dangerous killer animals on the African savanna. Rather than postulate any specific genes for language， I suggest that there was systematic selection for increase in brain size， allowing for more complex social cognition， including the “grammaticalization” of communication through learning and cultural pressures. Parallel to this development， the medium of communication changed gradually from a manual mode to a facial and then vocal mode， culmination in a mutation of the FOXP2 gene that gave our own species， Homo sapiens， the capacity for autonomous speech. This final switch may explain the so-called “human revolution，” leading to the dominance of humans on the planet， and the demise of other species of the genus Homo.