Large numbers of vertebrates began rapid population decline in the late 19th century

作者：Haipeng Li, Jinggong Xiangyu, Guangyi Dai, Zhili Gu, Ming Chen, Zongfeng Yang, Oliver A. Ryder, Wen‐Hsiung Li, Yun‐Xin Fu, Ya-Ping Zhang · 发表于：Proceedings of the National Academy of Sciences · 年份：2016 · DOI：10.1073/pnas.1616804113 · 被引用次数：64 · 研究领域：Genetic diversity and population structure、Wildlife Ecology and Conservation、Fish Ecology and Management Studies

Accelerated losses of biodiversity are a hallmark of the current era. Large declines of population size have been widely observed and currently 22,176 species are threatened by extinction. The time at which a threatened species began rapid population decline (RPD) and the rate of RPD provide important clues about the driving forces of population decline and anticipated extinction time. However, these parameters remain unknown for the vast majority of threatened species. Here we analyzed the genetic diversity data of nuclear and mitochondrial loci of 2,764 vertebrate species and found that the mean genetic diversity is lower in threatened species than in related nonthreatened species. Our coalescence-based modeling suggests that in many threatened species the RPD began ∼123 y ago (a 95% confidence interval of 20-260 y). This estimated date coincides with widespread industrialization and a profound change in global living ecosystems over the past two centuries. On average the population size declined by ∼25% every 10 y in a threatened species, and the population size was reduced to ∼5% of its ancestral size. Moreover, the ancestral size of threatened species was, on average, ∼22% smaller than that of nonthreatened species. Because the time period of RPD is short, the cumulative effect of RPD on genetic diversity is still not strong, so that the smaller ancestral size of threatened species may be the major cause of their reduced genetic diversity; RPD explains 24.1-37.5% of the ...