The Arctic wolf was first described as a distinct subspecies by British zoologist R. I. Pocock in 1935, after having examined a single skull from Melville Island. As of 2005[update], the Arctic wolf is still recognized as a distinct subspecies by Mammal Species of the World (MSW3). However, studies undertaken on Arctic wolf autosomal microsatellite DNA and Mitochondrial DNA (mtDNA) data indicate that the Arctic wolf has no unique haplotypes, thus indicating that its colonization of the Arctic Archipelago from the North American mainland was relatively recent, and thus not sufficient to warrant subspecies status. However, the research of Chambers et al. (2012) that dismissed the Arctic wolf's genetic integrity became controversial, forcing the United States Fish and Wildlife Service (USFWS) to commission a peer review of it, known as the National Center for Ecological Analysis and Synthesis (NCEAS) (2014). This peer review highlighted numerous flaws in the research such as the erroneous merging of the coastal British Columbia island wolves with the inland Canis lupus nubilus as well as suggesting that gray wolves never lived in the eastern third of the US, and thus concluded unanimously that the Chambers' review "is not accepted as consensus scientific opinion or best available science. "