DO PERIODICITIES IN EXTINCTION—WITH POSSIBLE ASTRONOMICAL CONNECTIONS—SURVIVE A REVISION OF THE GEOLOGICAL TIMESCALE?

摘要

A major revision of the geological timescale was published in 2012. We re-examine our past finding of a 27?Myr periodicity in marine extinction rates by re-assigning dates to the extinction data used previously. We find that the spectral power in this period is somewhat increased, and persists at a narrow bandwidth, which supports our previous contention that the Nemesis hypothesis is untenable as an explanation for the periodicity that was first noted by Raup & Sepkoski in the 1980s. We enumerate a number of problems in a recent study comparing extinction rates with time series models.