Short CommunicationIs the COI barcoding gene involved in speciation through intergenomic conflict?

We here test the proposition that changes in the barcoding region of COI are commonly involved in speciation through intergenomic conflict. We demonstrate that this is unlikely given that even with incomplete taxon sampling, 78-90% of closely-related animal species have identical COI amino acid sequences. In addition, in those cases where amino acid substitutions between closely related species are observed, the inter- and intra-specific substitution patterns are very similar and/or lack consistent differences in the number, position and type of amino acid change. Overall, we conclude that there is little evidence for a widespread involvement of the barcoding gene in speciation.

Graphical abstractDownload full-size imageHighlights► We test and reject the hypothesis that the barcoding gene is commonly involved in speciation through intergenomic conflict. ► We find that 78-90% of all closely related species lack amino acid substitutions. ► AA substitution patterns do not differ between intra- and inter-specific COI sequence pairs of similar nucleotide divergence.