As biological and linguistic diversity, the world's cultural diversity is on decline. However, to date there are no estimates of the rate at which the specific cultural traits of a group disappear, mainly because we lack empirical data to assess how the cultural traits of a given population change over time. Here we estimate changes in cultural traits associated to the traditional knowledge of wild plant uses among an Amazonian indigenous society. We collected data among 1151 Tsimane' Amerindians at two periods of time. Results show that between 2000 and 2009, Tsimane' adults experienced a net decrease in the report of plant uses ranging from 9% (for the female subsample) to 26% (for the subsample of people living close to towns), equivalent to a 1 to 3 % per year. Results from a Monte Carlo simulation show that the observed changes were not the result of randomness. Changes were more acute for men than for women and for informants living in villages close to market towns than for informants settled in remote villages. The Tsimane' could be abandoning their traditional knowledge as they perceive that this form of knowledge do not equip them well to deal with the new socio-economic and cultural conditions they face nowadays.

中文翻译：

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当代土著社会传统知识丧失的证据。

由于生物和语言的多样性，世界的文化多样性正在下降。然而，迄今为止，还没有估计一个群体的特定文化特征消失的速度，主要是因为我们缺乏经验数据来评估特定人群的文化特征如何随时间变化。在这里，我们估计了亚马逊土著社会中与野生植物使用传统知识相关的文化特征的变化。我们在两个时间段收集了 1151 名 Tsimane 美洲印第安人的数据。结果显示，在 2000 年至 2009 年期间，Tsimane 的成年人在植物使用报告中经历了从 9%（对于女性子样本）到 26%（对于居住在城镇附近的人的子样本）的净减少，相当于 1至每年 3%。蒙特卡洛模拟的结果表明，观察到的变化不是随机性的结果。男性的变化比女性更剧烈，居住在靠近集镇的村庄的线人比定居在偏远村庄的线人更剧烈。Tsimane 人可能正在放弃他们的传统知识，因为他们认为这种形式的知识无法让他们很好地应对他们如今面临的新的社会经济和文化条件。