Data on ancient microorganisms causes skepticism

Abstract

The critiques by Weyrich et al . (2014) and any other colleague on our paper analyzing the evolutionary history of genes involved in quorum sensing are certainly welcome, although the former seem to be based on several erroneous assumptions. The skepticism associated with any publication dealing with apparently ancient bacteria is completely understood because of the possible problems associated with contamination. However, and in contradiction to what Weyrich et al . mention, we did not fail to address previous publications; we are very well aware of them. We carry out these experiments as carefully as any microbiologist would: granted, contamination may still occur, but our own procedures indicate directly or indirectly that there is no contamination by extant bacteria or remaining DNA. Arguments for or against demonstration of the resilience of bacteria and biological molecules will go on, as it would be impossible to answer every single one of the critiques by doing yet further experiments. As responsible scientists, we can only present data obtained from carefully designed experiments, present the data to peer review, and let the readers draw their own conclusions. We were very aware that our results would be met with skepticism, given the belief in the apparent impossibility of the survival of microorganisms over a certain period of time. A similar response occurred when other colleagues reported the viable but nonculturable state. However, as we dig deeper into this area, we …