Evidence for periodicities in the extinction record? Response to Melott & Bambach [arXiv:1307.1884]

TL;DR

This paper defends previous findings that there is no strong evidence for periodicities in the extinction record, emphasizing that alternative models better explain the data than periodic ones.

Contribution

It provides a detailed rebuttal to criticisms of their earlier analysis, reaffirming that no significant periodicity is supported by the extinction data.

Findings

No strong evidence for periodicity in extinction record

Alternative models explain extinction data better

Criticisms of model comparison are largely unfounded

Abstract

In a recent paper, we applied time series analysis methods to study the possible influence of the solar motion through the Galaxy on terrestrial extinction (Feng & Bailer-Jones 2013). We drew conclusions about the relative probabilities of how well different models explain the geological extinction record. We found no strong evidence for either a periodicity in the extinction record or for a link between the solar orbit and this extinction record. In response to this, Melott & Bambach (2013) dedicate the majority of their article to criticizing our analysis. Their main objection is to evidence-based model comparison. Here we deal with their criticisms one by one, and show that they are largely misplaced, leaving our conclusions unaffected. The bottom line is that although one can get a periodic model at some period to fit the extinction data, there are other models which explain the data better.