What would your ideas about language evolution be if there was only one language left on earth? Fortunately, our investigation need not be that impoverished. In the present article, we survey the state of knowledge regarding the kinds of language found among humans, the language inventory, population sizes, time depth, grammatical variation, and other relevant issues that a theory of language evolution should minimally take into account.

中文翻译：

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语言多样性和语言进化

如果地球上只剩下一种语言，你对语言进化的看法是什么？幸运的是，我们的调查不必如此贫乏。在本文中，我们调查了有关人类语言种类、语言库存、人口规模、时间深度、语法变异以及语言进化理论应最低限度考虑的其他相关问题的知识状态。