Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia.
Nat Ecol Evol. 2024 Oct;8(10):1991-2002. doi: 10.1038/s41559-024-02488-4. Epub 2024 Sep 5.
Islands have played a prominent role in evolutionary and ecological theory, centring the theoretical framework for understanding biodiversity in terms of isolation and area and providing 'laboratories' of evolutionary change and adaptive radiation. However, a similar role for islands in understanding global language diversity has not been established, even though one-sixth of the world's languages are spoken on islands which account for <1% of the inhabited land area. The striking diversity of island languages remains largely unexplained. We construct a global database which reveals that 10% of the world's languages are endemic to islands (landmasses <11,000 km) and we test several key theories of language evolution and diversity. We show that language diversity on islands increases with area but does not show a steady decrease with isolation, nor are island languages at elevated risk of loss. However, number of endemic languages per island increases with both area and isolation. We demonstrate that islands shape language evolution, with fewer phonemes (distinct sounds) in island endemic languages with increasing isolation. Our results suggest that islands generate language diversity by accelerating both language change and diversification.
岛屿在进化和生态理论中扮演着重要的角色，其为理解生物多样性的隔离和面积理论框架提供了核心，同时为进化改变和适应性辐射提供了“实验室”。然而，岛屿在理解全球语言多样性方面的类似作用尚未得到确立，尽管世界上六分之一的语言是在占居住土地面积不到 1%的岛屿上使用的。岛屿语言的惊人多样性在很大程度上仍未得到解释。我们构建了一个全球数据库，揭示了世界上 10%的语言是岛屿特有（陆地面积<11000 平方公里）的，并且我们测试了几种关键的语言进化和多样性理论。我们表明，岛屿上的语言多样性随着面积的增加而增加，但与隔离的关系并不稳定，岛屿语言也没有更高的灭绝风险。然而，每个岛屿的特有语言数量随着面积和隔离的增加而增加。我们证明了岛屿塑造了语言进化，随着隔离程度的增加，岛屿特有语言中的音位（不同的声音）减少。我们的研究结果表明，岛屿通过加速语言变化和多样化来产生语言多样性。
