Fractal power spectra plotted upside-down Comment on 'Scaling of power spectrum of extinction events in the fossil record' by V.P. Dimri and M.R. Prakash

摘要

Fossil extinction power spectra, recently published by Dimri and Prakash [1], appear to exhibit power-law scaling in which spectral power is inversely proportional to frequency. Dimri and Prakash interpret their results as demonstrating a fractal pattern in the fossil record, with long-range correlations that suggest self-organized critical dynamics. Here I point out that their methods are vulnerable to biases and artifacts, and I show that their conclusions are based on power spectra that have been plotted upside-down.