THE EVOLUTIONARY HISTORY OF CETACEAN BRAIN AND BODY SIZE
THE EVOLUTIONARY HISTORY OF CETACEAN BRAIN AND BODY SIZE
复制标题
DOI：
10.1111/evo.12197
复制
发表时间：
2013-11-01
期刊：
影响因子：
3.3
通讯作者：
Gatesy, John
中科院分区：
文献类型：
--
作者：
Montgomery, Stephen H.;Geisler, Jonathan H.;Gatesy, John
鲸目动物在大脑大小方面与灵长类动物的身体大小相匹敌，包括有史以来进化出的大脑和身体最大的物种。鲸目动物非常多样化，在两种表型上都有几个数量级的差异，在现存的两个亚目Mystieti和Odontoceti之间有显著的差异。我们分析了脑和体质量的进化历史，以及用脑化商(EQ)测量的相对脑大小，使用灭绝和现存类群的数据集来捕捉进化模式和方向的时间变化。我们的结果表明，鲸目动物的大脑和身体质量在强烈的方向性趋势下进化，并随着时间的推移而增加，但情商的下降是普遍的。神秘动物的EQ明显低于齿类动物，这是由于大脑的变化：由于Mystieti的身体质量迅速增加和Odontoceti的身体质量减少而导致的亚目分化后的身体异速生长。鲸目动物的模式与灵长类动物的模式形成对比，灵长类动物的大脑质量和相对大脑大小有明显增加的趋势，但身体质量没有增加。我们讨论了这些分析揭示了大型大脑的汇聚进化，并强调直到最近最脑化的哺乳动物是齿类动物，而不是灵长类动物。
Cetaceans rival primates in brain size relative to body size and include species with the largest brains and biggest bodies to have ever evolved. Cetaceans are remarkably diverse, varying in both phenotypes by several orders of magnitude, with notable differences between the two extant suborders, Mysticeti and Odontoceti. We analyzed the evolutionary history of brain and body mass, and relative brain size measured by the encephalization quotient (EQ), using a data set of extinct and extant taxa to capture temporal variation in the mode and direction of evolution. Our results suggest that cetacean brain and body mass evolved under strong directional trends to increase through time, but decreases in EQ were widespread. Mysticetes have significantly lower EQs than odontocetes due to a shift in brain:body allometry following the divergence of the suborders, caused by rapid increases in body mass in Mysticeti and a period of body mass reduction in Odontoceti. The pattern in Cetacea contrasts with that in primates, which experienced strong trends to increase brain mass and relative brain size, but not body mass. We discuss what these analyses reveal about the convergent evolution of large brains, and highlight that until recently the most encephalized mammals were odontocetes, not primates.