Restrictions on biological adaptation in language evolution
Restrictions on biological adaptation in language evolution
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DOI：
10.1073/pnas.0807191106
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发表时间：
2009-01-27
影响因子：
11.1
通讯作者：
Christiansen, Morten H.
中科院分区：
文献类型：
--
作者：
Chater, Nick;Reali, Florencia;Christiansen, Morten H.
语言习得和语言加工受遗传制约。一个关键的尚未解决的问题是，这些基因限制与语言共同进化了多远，可能导致高度专业化和物种特异性的语言“模块”，以及语言习得和处理在多大程度上重新部署了先前存在的认知机制。在目前的工作中，我们探索了编码语言特定属性的基因可能与语言本身共同进化的情况。我们提出了一个理论模型，在计算机模拟中实现了基因和语言相互作用的关键方面。我们的研究结果表明，语言基因只能与语言环境的高度稳定方面共同进化；快速变化的语言环境不能为自然选择提供稳定的目标。因此，一种生物禀赋不可能与作为习得的文化习俗而开始的语言特性共同进化，因为文化习俗的变化比基因要快得多。我们认为，这排除了语言的任意属性，包括控制短语结构的抽象语法原则，大小写标记和一致性，已经通过自然选择构建到“语言模块”中的可能性。人类语言习得和处理的遗传基础并不与语言共同进化，而主要是在语言出现之前。正如达尔文提出的那样，语言与其潜在机制之间的契合之所以出现，是因为语言的进化是为了适应人类的大脑，而不是相反。
Language acquisition and processing are governed by genetic constraints. A crucial unresolved question is how far these genetic constraints have coevolved with language, perhaps resulting in a highly specialized and species-specific language "module,'' and how much language acquisition and processing redeploy preexisting cognitive machinery. In the present work, we explored the circumstances under which genes encoding language-specific properties could have coevolved with language itself. We present a theoretical model, implemented in computer simulations, of key aspects of the interaction of genes and language. Our results show that genes for language could have coevolved only with highly stable aspects of the linguistic environment; a rapidly changing linguistic environment does not provide a stable target for natural selection. Thus, a biological endowment could not coevolve with properties of language that began as learned cultural conventions, because cultural conventions change much more rapidly than genes. We argue that this rules out the possibility that arbitrary properties of language, including abstract syntactic principles governing phrase structure, case marking, and agreement, have been built into a "language module'' by natural selection. The genetic basis of human language acquisition and processing did not coevolve with language, but primarily predates the emergence of language. As suggested by Darwin, the fit between language and its underlying mechanisms arose because language has evolved to fit the human brain, rather than the reverse.