Kirchner J W, Weil A
Department of Geology and Geophysics, University of California, Berkeley 94720-4767, USA.
Proc Biol Sci. 2000 Jul 7;267(1450):1301-9. doi: 10.1098/rspb.2000.1142.
Recent analyses have suggested that extinction and origination rates exhibit long-range correlations, implying that the fossil record may be controlled by self-organized criticality or other scale-free internal dynamics of the biosphere. Here we directly test for correlations in the fossil record by calculating the autocorrelation of extinction [corrected] and origination rates through time. Our results show that extinction rates are uncorrelated beyond the average duration of a stratigraphic interval. Thus, they lack the long-range correlations predicted by the self-organized criticality hypothesis. In contrast, origination rates show strong autocorrelations due to long-term trends. After detrending, origination rates generally show weak positive correlations at lags of 5-10 million years (Myr) and weak negative correlations at lags of 10-30 Myr, consistent with aperiodic oscillations around their long-term trends. We hypothesize that origination rates are more correlated than extinction rates because originations of new taxa create new ecological niches and new evolutionary pathways for reaching them, thus creating conditions that favour further diversification.
近期分析表明，灭绝速率和起源速率呈现出长程相关性，这意味着化石记录可能受生物圈的自组织临界性或其他无标度内部动力学控制。在此，我们通过计算灭绝[校正后]速率和起源速率随时间的自相关性，直接检验化石记录中的相关性。我们的结果表明，在地层间隔的平均持续时间之外，灭绝速率不相关。因此，它们缺乏自组织临界性假说所预测的长程相关性。相比之下，由于长期趋势，起源速率显示出很强的自相关性。去除趋势后，起源速率通常在滞后500万至1000万年（Myr）时表现出弱正相关，在滞后1000万至3000万年时表现出弱负相关，这与围绕其长期趋势的非周期性振荡一致。我们推测，起源速率比灭绝速率的相关性更强，因为新分类群的起源创造了新的生态位以及通向这些生态位的新进化途径，从而创造了有利于进一步多样化的条件。
