Population Genetics of the Greater Grison (Galictis vittata; Mustelidae, Carnivora) and How Changes Since Miocene–Pliocene Have Shaped the Phylogenetic Relationships Between Grison Species and Other Neotropical Mustelid Genera

Mustelids are a very diverse carnivoran group, boasting the largest number of carnivoran species today, with the most extreme ecological adaptations. Nevertheless, Neotropical Lyncodontini, one Neotropical mustelid subfamily, is one of the least studied from a genetic and evolutionary perspective. The use of small fragments of three mitochondrial (mt) markers (NADH5, 12S rRNA, and D-loop) proved to be very useful for recovering relevant information on the evolutionary history of Neotropical Lyncodontini species of the genera Galictis and Lyncodon. This study used the largest population sample analyzed to date for G. vittata (13 specimens from Guatemala, Colombia, Ecuador, Peru, Bolivia, and French Guiana) and reports for the first time sequences for three mt markers for L. patagonicus other than the mtCyt-b gene. The main results obtained were the following. (1) The haplotype and nucleotide diversity of G. vittata was lower than these statistics measured in other studies of G. cuja in southern and southeastern Brazil. (2) There was evidence from two analyses of a possible population expansion of the female lineages of G. vittata, which began between 635,000 and 370,000 years ago (ya) (mismatch distribution), whereas another procedure (BSP) detected population growth from 500,000 to 80,000 ya, with a population decrease around 40,000 ya. (3) Three genetically distinct groups were detected within G. vittata. One group was in Central America and northern Colombia, another in French Guiana, and the third in the rest of South America. (4) The origin of Neotropical Lyncodontini was older than in other studies (late Miocene, early Pliocene). (6) Some of the analyses detected a closer relationship between L. patagonicus and G. cuja than the latter with G. vittata. This could show that Galictis might be a paraphyletic genus. (7) Many analyses detected that the L. patagonicus haplotypes were the first to originate in situ in South America before the definitive closure of the isthmus of Panama, followed by those of G. cuja, with G. vittata showing the most recent haplotypes. This could indicate that the origin of the current Neotropical Lyncodontini occurred in the south of South America and that colonization occurred towards the north.