据5月22日的《科学》杂志报道说,在过去的40年中,大象、犀牛和长颈鹿在非洲大草原上生生息息,它们死后的遗骨可靠地反映了这些动物群体是如何适应生态变化的。 保护生物学家和古生物学家在利用遗骨和化石来重构古代生态社群时一般会做一个小小的主观假定。 如今,研究人员采用了一种非常耐心的方法来评估死去动物的遗存物究竟是如何反映活着的动物的社群的。
David Western 和Anna K. Behrensmeyer对肯尼亚南部的Amboseli生态系统进行了为期40年的研究。他们分析了在过去的40年中,在整个非洲大草原上死去的15种食草动物的骨组合。
研究人员将骨纪录与这些动物的群体组成和栖息地的变化进行了比较,这些变化是由从茂密的森林和灌木丛演变为更为开阔的有着较大沼泽地的草原所驱动的。 随着栖息地的这一变化,食草动物的丰沛程度相对于食叶动物来说有所增加,而物种的丰富程度则减少了。 研究人员报告说,动物的骨组合的确精准地尾随着这些变化,其间隔期可以短至5年。(生物谷Bioon.com)
生物谷推荐原始出处:
Science 22 May 2009:DOI: 10.1126/science.1171155
Bone Assemblages Track Animal Community Structure over 40 Years in an African Savanna Ecosystem
David Western1 and Anna K. Behrensmeyer2
Reconstructing ancient communities depends on how accurately fossil assemblages retain information about living populations. We report a high level of fidelity between modern bone assemblages and living populations based on a 40-year study of the Amboseli ecosystem in southern Kenya. Relative abundance of 15 herbivorous species recorded in the bone assemblage accurately tracks the living populations through major changes in community composition and habitat over intervals as short as 5 years. The aggregated bone sample provides an accurate record of community structure time-averaged over four decades. These results lay the groundwork for integrating paleobiological and contemporary ecological studies across evolutionary and ecological time scales. Bone surveys also provide a useful method of assessing population changes and community structure for modern vertebrates.
1 African Conservation Center, Box 62844, Nairobi, Kenya.
2 Department of Paleobiology, MRC 121, National Museum of Natural History, Smithsonian Institution, Post Office Box 37012, Washington, DC 20013–7012, USA.