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脊椎动物在德纪末期大规模灭绝后的体型缩小

Lauren Sallan¹, Andrew K Galimberti²

¹Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104, USA. lsallan@sas.upenn.edu.

Science (New York, N.Y.)

|November 14, 2015

概括

脊椎动物在德沃纪灭绝后的3600万年缩小,这是由生态因素而不是气候驱动的. 占主导地位, 塑造未来的生物多样性.

科学领域:

古生物学
进化生物学
生态系统动力学

背景情况:

德纪末期的大规模灭绝对脊椎动物产生了深远的影响.
灭绝后的恢复期对于理解进化轨迹至关重要.
之前的研究已经探讨了灭绝事件,但对随后的长期身体大小趋势却不那么关注.

研究的目的:

调查在德纪末期大规模灭绝后脊椎动物体型变化的驱动因素和持续时间.
确定环境因素 (氧气,温度) 或生态压力是否影响了脊椎动物的体型缩小.
分析灭绝后的小型与大型脊椎动物的多样化模式.

主要方法:

对化石记录进行分析,以追踪脊椎动物在灭绝后3600万年的体型趋势.
相关性分析以评估身体尺寸变化与环境参数 (氧气,温度) 之间的关系.
对小型快繁殖和大型慢繁殖脊椎动物群的多样化率进行比较研究.

主要成果:

脊椎动物在灭绝后至少有3600万年的时间表现出身体大小的持续减少.
全球体型缩小与氧气水平或温度的变化无关.
小型,快速繁殖的光鱼,鱼和四足动物 (不到1米) 辐射并主导生态系统,而大体的幸存者表现出有限的多样化并面临灭绝.

结论:

生态驱动因素,而不是环境因素,是类灭绝后脊椎动物体型趋势的主要影响因素.
灭绝后的恢复间隔反映了现代的生态继承,大小和生命历史特征的活跃选择.
全球脊椎动物和鱼类生物群的破坏通常会导致广泛的长期体型减少,从根本上构建未来的生物多样性.

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