The delayed rise of present-day mammals
The delayed rise of present-day mammals
复制标题
DOI：
10.1038/nature05634
复制
发表时间：
2007-03-29
期刊：
影响因子：
64.8
通讯作者：
Purvis, Andy
中科院分区：
文献类型：
--
作者：
Bininda-Emonds, Olaf R. P.;Cardillo, Marcel;Purvis, Andy
白垩纪末期的大规模灭绝事件消灭了非鸟类恐龙和大多数现有动物群，是否引发了当今哺乳动物的进化辐射？在这里，我们构建、测定和分析了几乎所有现存哺乳动物的物种水平系统发育，为这个问题带来了新的视角。我们对现存谱系如何随时间积累的分析表明，在白垩纪/第三纪边界上，每个谱系的净多样化率几乎没有变化。相反，这些速率随着目前公认的胎盘总目和目大约9300万年前的起源而显着上升，然后下降并保持在较低水平，直到在整个始新世和渐新世时期再次加速。我们的研究结果表明，导致现存胎盘目爆发的系统发育“熔断”不仅比之前怀疑的要长得多，而且还挑战了白垩纪末大规模灭绝事件对当今哺乳动物的多样化产生重大直接影响的假设。
Did the end-Cretaceous mass extinction event, by eliminating non-avian dinosaurs and most of the existing fauna, trigger the evolutionary radiation of present-day mammals? Here we construct, date and analyse a species-level phylogeny of nearly all extant Mammalia to bring a new perspective to this question. Our analyses of how extant lineages accumulated through time show that net per-lineage diversification rates barely changed across the Cretaceous/Tertiary boundary. Instead, these rates spiked significantly with the origins of the currently recognized placental superorders and orders approximately 93 million years ago, before falling and remaining low until accelerating again throughout the Eocene and Oligocene epochs. Our results show that the phylogenetic 'fuses' leading to the explosion of extant placental orders are not only very much longer than suspected previously, but also challenge the hypothesis that the end-Cretaceous mass extinction event had a major, direct influence on the diversification of today's mammals.