Recent analyses have suggested that extinction and origination rates exhibi
t long-range correlations, implying that the fossil record may be controlle
d by self-organized criticality or other scale-free internal dynamics of th
e biosphere. Here we directly lest for correlations in the fossil record by
calculating the autocorrelation of the extinction and origination rates th
rough 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-ter
m trends. After detrending, origination rates generally show weak positive
correlations at lags of 5-10 million years (Myr) and weak negative correlat
ions at lags of 10-30 Myr, consistent with aperiodic oscillations around th
eir long-term trends. We hypothesize that origination rates are more correl
ated than extinction rates because originations of new taxa create new ecol
ogical niches and new evolutionary pathways for reaching them, thus creatin
g conditions that favour further diversifications.