The science of the global coverage of lichen is a cautionary tale
The history of science is replete with successes and failures, leaps and missteps. The missteps can be instructive to the the winding nature of science.
In the world of science, and science communications, it’s important to have established facts. A consensus can help provide context and establish a foundation to resolve discrepancies in different points of view.
But what happens when particular facts don’t have any evidence to back them up? This happens more often than you may think.
In an fascinating paper published recently by a trio of Canadian biologists, the authors provide a case study showing how an unsubstantiated estimate of lichen coverage across the globe has been cited in academic articles and documents as, well as the media, for more than 35 years.
By their count there were over 4.000 citations during that time – with some citation chains lacking attribution to the source and instances where the number or context changed over time. It’s clear to see how this harms science communications and science writ large. And while this is primarily a result of a lack of due diligence, it is no less harmful than if it was purposeful.
What does this have to do with Lyme disease? This paper is both an interesting read and also a sobering reminder of how a false statement can spread, change over time, and be repeated without needing evidence.
There are many examples of this in the Lyme disease field, and undoubtedly many other fields. For example, the length of time needed for a human to be infected by a feeding tick is often stated with unwarranted certainty. This certainty is inconsistent with what is (not) known.
The effectiveness (or lack thereof) of diagnostic tests is likewise contentious and claims are often poorly supported by real-world evidence. It’s incumbent upon all people, but particularly those in positions of authority and privilege to carefully evaluate the information that they state and cite and share.
Citation
Katherine H I Drotos, Douglas W Larson, R Troy McMullin, Scientific telephone: The cautionary tale of the global coverage of lichens, BioScience, Volume 74, Issue 7, July 2024, Pages 473–477, https://doi.org/10.1093/biosci/biae048.
Abstract
Scientific history has many examples of profound statements that are later found to be unsubstantiated. The consequences of such misinformation can be dire. In the present article, we present a case where an unevidenced estimate of global lichen coverage proliferated through both scientific literature and popular media. We traced this estimate to a non-peer-reviewed publication from 1987. We found 76 academic articles (collectively cited 4125 times) and 13 other academic documents citing the statistic, citation chains without source attribution, and instances where the number or context was changed. We also found the statistic 37 times in popular media, which is especially concerning, given that these media communicate science to the broader public. We demonstrate how an unevidenced statement can spread, change through time, and ultimately be repeated without demand for evidence. We hope this case unplugs the telephone and provides a cautionary tale for researchers to ensure critical evaluation of citation and communication practices.
