Millien Virginie
Redpath Museum, McGill University, Montreal, Quebec, Canada.
PLoS Biol. 2006 Oct;4(10):e321. doi: 10.1371/journal.pbio.0040321.
Dramatic evolutionary changes occur in species isolated on islands, but it is not known if the rate of evolution is accelerated on islands relative to the mainland. Based on an extensive review of the literature, I used the fossil record combined with data from living species to test the hypothesis of an accelerated morphological evolution among island mammals. I demonstrate that rates of morphological evolution are significantly greater--up to a factor of 3.1--for islands than for mainland mammal populations. The tendency for faster evolution on islands holds over relatively short time scales--from a few decades up to several thousands of years--but not over larger ones--up to 12 million y. These analyses form the first empirical test of the long held supposition of accelerated evolution among island mammals. Moreover, this result shows that mammal species have the intrinsic capacity to evolve faster when confronted with a rapid change in their environment. This finding is relevant to our understanding of species' responses to isolation and destruction of natural habitats within the current context of rapid climate warming.
在岛屿上隔离的物种会发生显著的进化变化，但目前尚不清楚相对于大陆而言，岛屿上的进化速度是否会加快。基于对文献的广泛综述，我利用化石记录并结合现存物种的数据，来检验岛屿哺乳动物形态进化加速这一假设。我证明，岛屿哺乳动物的形态进化速度显著快于大陆哺乳动物种群，快达3.1倍。岛屿上更快进化的趋势在相对较短的时间尺度上成立——从几十年到几千年——但在更长的时间尺度上则不然——长达1200万年。这些分析首次对长期以来关于岛屿哺乳动物进化加速的假设进行了实证检验。此外，这一结果表明，当面临环境的快速变化时，哺乳动物物种具有更快进化的内在能力。这一发现对于我们理解在当前快速气候变暖背景下物种对自然栖息地隔离和破坏的反应具有重要意义。
