Baraminic Classification of the Tuatara (Sphenodon punctatus) among Reptiles Based on Whole-Genome K-mer Signature Comparison


The red panda is a curiosity of biological classification. Taxonomists have come to different conclusions on its placement depending on which characteristics are considered. It was once considered closely related to bears (ursids), other times to raccoons (procyonids), or animals such as skunks (mephitids), badgers, otters, or martens (mustelids). Perhaps the red panda belongs to its own group. Since the whole genome sequence was available for this organism, the Whole Genome k-mer Signature algorithm was used to classify the red panda. Mitochondrial DNA and cytochrome-b protein sequence similarity was also measured to help determine the baraminic status of the red panda. According to the whole genome analysis, the red panda groups with the mustelids, apart from ursids. The placement of mephitids is uncertain. According to the mitochondrial DNA analysis, the red panda is part of a cluster discontinuous with mustelids and all other groups. However, when the sequence identity of the cytochrome-b protein is assessed, it appears that the red panda again shows continuity with mustelids, and discontinuity with ursids. Mephitids also show discontinuity with mustelids. The difference between the whole genome and mitochondrial results could be due to nucleo-mitochondrial discordance, a common phenomenon. A higher number of four-fold degenerate sites in the mitochondrial cyt-b compared to the first exon of the nuclear RAG1 gene support this. Based on these results, it is likely that the red panda belongs to the mustelid holobaramin, although further baraminology studies are warranted, both morphological and molecular.