Sepkoski J J
Department of the Geophysical Sciences, University of Chicago, IL 60637, USA.
Science. 1987 Jan 2;235:64-6. doi: 10.1126/science.11539724.
Extinction intensities calculated from 505 Paleozoic marine assemblages divided among six environmental zones and 40 stratigraphic intervals indicate that whole communities exhibit increasing extinction offshore but that genera within individual taxonomic classes tend to have their highest extinction onshore. The offshore trend at the community level results from a concentration of genera in classes with low characteristic extinction rates in nearshore environments. This finding is consistent with the ecologic expectation that organisms inhabiting unpredictably fluctuating environments should suffer more extinction than counterparts living under more predictably equitable conditions.
根据505个古生代海洋生物群落计算得出的灭绝强度，这些群落分布在六个环境区域和40个地层间隔中，结果表明，整个群落的灭绝在近海处增加，但各个分类类别的属在陆地上往往具有最高的灭绝率。群落水平上的近海趋势是由于近岸环境中特征灭绝率低的类别的属集中所致。这一发现与生态学预期一致，即生活在不可预测波动环境中的生物应该比生活在更可预测公平条件下的同类生物遭受更多的灭绝。
