Emergence of a sixth mass extinction
Emergence of a sixth mass extinction
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第六次大规模灭绝的出现
DOI：
10.1093/biolinnean/blx063
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发表时间：
2017
影响因子：
1.9
通讯作者：
J. C. Briggs
中科院分区：
文献类型：
--
作者：
J. C. Briggs
最近，两篇文章发表在领先的科学期刊上，每篇文章都呼吁关注正在出现的大规模灭绝。两者是互补的，因为它们通过使用来自对比环境的数据得出了相同的结论。但是，在每种情况下，重要的问题是，可以从现有的证据中自信地预测大灭绝的开始吗？这两篇文章是几篇出版物中的最新一篇，这些出版物指出地球正处于大灭绝时期的开始，最终将导致大约75%的生物物种消失。最近一次如此大规模的灭绝发生在大约6500万年前的白垩纪末期。新的大规模灭绝预测开始于大约22年前，基于对物种灭绝的估计，由于人类活动，每年有数千种物种灭绝。尽管这种没有根据的估计很快就被基于文献记录的更现实的近似值所取代，但大规模灭绝的幽灵仍然存在。然而，我发现的证据表明，在过去的500年里，人类造成的物种灭绝每年只有大约1.5个物种，这些损失可能与同期出生的物种（物种形成）相等或超过。如果没有大量净物种损失的证据，大规模灭绝就成为一种没有实质内容的猜测。世界上最大的保护问题不是物种灭绝，而是种群数量下降到许多物种只作为它们以前丰富的残余物而存在。
Recently, two articles were published in leading scientific journals, each calling attention to an emerging mass extinction. The two are complementary in that they reached the same conclusion by using data from contrasting environments. But, the important question in each case is, can the beginning of a mass extinction be confidently predicted from the evidence presented? The two articles are the latest of several publications that have stated the Earth is in the beginning of a great extinction episode that will eventually result in the loss of at about 75% of all living species. The most recent extinction of this magnitude occurred at the close of the Cretaceous about 65 million years ago. The new mass extinction prognosis began about 22 years ago and was based on estimates of species extinction, due to human activities, that had reached thousands of species per year. Although such unsupported estimates soon gave way to more realistic approximations based on documented records, the spectre of a mass extinction has remained. However, I have found evidence that human-caused extinctions have amounted to only about 1.5 species per year for the last 500 years and that these losses have probably been equalled or surpassed by species born (speciation) during that time. Without evidence of substantial net species loss, mass extinction becomes a speculation without substance. The world’s greatest conservation problem is not species extinction but population decline to the point where many species exist only as remnants of their former abundance.