Genetic diversity, structure, and demographic histories of unique and ancient wolf lineages in India

Abstract

Assessing genetic diversity, population connectivity, demographic patterns, and phylogeographic relationships is vital for understanding the evolutionary history of species and thus aid in conservation management decisions. Indian wolves (currently, Canis lupus pallipes and Canis lupus chanco) are considered ancient, unique and divergent lineages among grey wolves, yet their population genetics are poorly understood. To void this knowledge gap, we collected samples from Indian peninsular (n = 77) and Himalayan wolves (n = 24) and used a combination of maternal (mtDNA CR and Cyt b) and bi-parental (nuclear microsatellites) markers to estimate levels of genetic diversity, examine the patterns of genetic structuring between them and within their distribution range, and assess their demographic histories. Both the wolf populations showed moderate levels of genetic variability, comparable to other grey wolves. Low levels of genetic differentiation were observed within both the Indian peninsular and Himalayan wolves indicating high levels of gene flow within their populations. On the other hand, high levels of genetic differentiation were observed between the two wolves indicating absence of gene flow. Molecular analysis highlighted the uniqueness of both the Indian wolves which was further supported by the presence of unique haplotypes indicating no admixture between them. Demographic analysis using both mtDNA and microsatellites revealed decline in population sizes of both the wolf lineages and both have undergone bottlenecks. Estimates of past effective population size revealed recent population declines of both lineages of Indian wolves at around 25–50 generations corresponding to about 100–200 years ago. Our results further support the designation of both lineages of Indian wolves as two distinct species Canis pallipes and Canis himalayensis and suggest increasing conservation efforts to save the unique and ancient wolf species from extinction.