The Use of Mean Instead of Smallest Interspecific Distances Exaggerates the Size of the “Barcoding Gap” and Leads to Misidentification

Abstract

DNA barcoding is one of the best funded and most visible large-scale initiatives in systematic biology and has generated both much interest and controversy. DNA barcoding has also attracted significant support from foundations that had previously shown little interest in systematics. Yet, the project is controversial because many systematists feel that currently the conceptual foundation of DNA barcoding remains weak. This problem can only be alleviated through additional research that can lead to improved tools and concepts. Here, we scrutinize a key concept of DNA barcoding, the so-called barcoding gap (Meyer and Paulay, 2005), and use empirical data to document that it needs to be computed based on the smallest instead of the mean interspecific distances.