URPP Language and Space, University of Zurich, Zurich, Switzerland.
Department of Geography, University of Zurich, Zurich, Switzerland.
Proc Biol Sci. 2018 Aug 22;285(1885):20172851. doi: 10.1098/rspb.2017.2851.
Linguistic diversity is a key aspect of human population diversity and shapes much of our social and cognitive lives. To a considerable extent, the distribution of this diversity is driven by environmental factors such as climate or coast access. An unresolved question is whether the relevant factors have remained constant over time. Here, we address this question at a global scale. We approximate the difference between pre- versus post-Neolithic populations by the difference between modern hunter-gatherer versus food-producing populations. Using a novel geostatistical approach of estimating language and language family densities, we show that environmental-chiefly climate factors-have driven the language density of food-producing populations considerably more strongly than the language density of hunter-gatherer populations. Current evidence suggests that the population dynamics of modern hunter-gatherers is very similar to that of what can be reconstructed from the Palaeolithic record. Based on this, we cautiously infer that the impact of environmental factors on language densities underwent a substantial change with the transition to agriculture. After this transition, the environmental impact on language diversity in food-producing populations has remained relatively stable since it can also be detected-albeit in slightly weaker form-in models that capture the reduced linguistic diversity during large-scale language spreads in the Mid-Holocene.
语言多样性是人类种群多样性的一个关键方面，塑造了我们的许多社会和认知生活。在很大程度上，这种多样性的分布是由气候或沿海通道等环境因素驱动的。一个悬而未决的问题是，相关因素是否随着时间的推移保持不变。在这里，我们在全球范围内解决了这个问题。我们通过现代狩猎采集者与粮食生产者之间的差异来近似新石器时代前后人口的差异。我们使用一种新的地理统计学方法来估计语言和语言家族的密度，结果表明，环境因素——主要是气候因素——对粮食生产者的语言密度的影响远远大于对狩猎采集者的语言密度的影响。目前的证据表明，现代狩猎采集者的人口动态与从旧石器时代记录中可以重建的情况非常相似。基于这一点，我们谨慎地推断，随着农业的发展，环境因素对语言密度的影响发生了重大变化。此后，在粮食生产者中，环境因素对语言多样性的影响一直相对稳定，因为即使在中全新世大规模语言传播期间语言多样性减少的模型中，也可以检测到这种影响（尽管形式略弱）。
