Wolves of the Indian subcontinent, both the Indian (Canis lupus pallipes) and Tibetan (Canis lupus Chanco) exhibit an unexpectedly large amount of unique genetic variation, according to a new study by Rice University in the United States.
Rice University professor Lauren Hennelly and her team, which includes scientists from 11 countries, collected and analysed DNA from wolves across Asia.
They found the southern part of Asia to be a hotbed for grey wolf diversity –— an evolutionarily important location that contains information about wolves’ past and hope for their future.
Wolves are traveling animals with reported journeys reaching over 500 miles. These travels often result in genetic mixing, making it easy to find traces of one wolf population mixed into the DNA of other populations.
For example, wolf populations across the vast areas of northern Asia and North America (the Holarctic wolves) are genetically very similar due to this genetic mixing, or gene flow.
“However, that was not the case for wolves in southern Asia. Hennelly’s data showed sharply defined geographical boundaries between the three main lineages, or populations, that split long ago with little gene flow between the different populations,” a statement by Rice University noted.
In fact, Hennelly’s team found that the ancient Indian and Tibetan wolf lineages were isolated from other wolves for over 100,000 years. There likely were past climatic factors such as habitat changes due to previous glacial cycles that led to this separation, but the distinction has remained through to current days, when the breaks between the populations have disappeared.
“We found that Pakistan is the global hotspot of gray wolf diversity. That is because this location is where all three major lineages of wolves — Indian, Tibetan and Holarctic — come together,” Hennelly said. “How and why these different types of wolves remain genetically distinct despite living so close to each other is a question that could help us understand fundamental questions in evolutionary biology, like the early stages of speciation.”
Conservationists have classified the grey wolf species as stable overall, but this dive into the genetics of Indian wolves made it clear that they needed to be considered separately from the wolves living in Europe and North America.
Hennelly co-led a working group that estimates the Indian wolf population contains around 3,000 individuals with a high risk of extinction in the foreseeable future. Under the International Union for the Conservation of Nature, the Indian wolf, like the Tibetan wolf, is now classified as threatened.
“Only through genetics could we understand that these are unique wolves found nowhere else,” Hennelly said. “These hotspots of wolf diversity in southern Asia are where grey wolves are most threatened, with wolves in the Indian subcontinent facing immense pressures. Our work not only informs the conservation status and taxonomy of these wolves but highlights the importance of conserving these three evolutionarily distinct populations, and preserving the full spectrum of wolf genetic diversity, before it’s too late.”
The study has been published in the journal Communications Biology.