LONGYEARBYEN, NORWAY - JULY 29: A Svalbard reindeer reclines while grazing during a summer heat wave on Svalbard archipelago on July 29, 2020 near Longyearbyen, Norway. The Svalbard reindeer are facing difficult winters due to the increasing frequency of freezing rain that obstructs the reindeer's ability to forage for vegetation. Svalbard archipelago, which lies approximately 1,200km north of the Arctic Circle, is currently experiencing a summer heat wave that set a new record in Longyearbyen on July 25 with a high of 21.7 degrees Celsius. Global warming is having a dramatic impact on Svalbard that, according to Norwegian meteorological data, includes a rise in average winter temperatures of 10 degrees Celsius over the past 30 years, creating disruptions to the entire local ecosystem.
A remarkable tale of survival exists in the freezing expanse of the Arctic, where the cold bites and the land seems barren and inhospitable.
It is the story of the Svalbard reindeer. This species has defied the odds, adapting to its harsh environment despite facing one of nature's most challenging problems: low genetic diversity.
A Genetic Paradox
Despite having the highest levels of inbreeding and the lowest genetic diversity among northern reindeer and caribou subspecies, the Svalbard reindeer thrives in the Arctic wilderness.
This is precisely the mystery that researchers at NTNU's Department of Natural History have been unraveling; we learn more in a report shared by Phys.org.
Nicolas Dussex, a postdoc at the department, explained, "Of all the subspecies of reindeer found in the high north, the Svalbard reindeer has the most inbreeding and the lowest genetic diversity."
Only 7,000-8,000 years ago, the first reindeer made their arduous journey to the Svalbard islands, likely from Russia via Novaya Zemlya and the islands of Franz Josef Land.
There might have been just a handful of these beats at that time. As evolutionary theory dictates, inbreeding should have been a recipe for disaster, leading to the accumulation of harmful mutations and genetic variants followed by disease and death.
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Remarkable Adaptations
Yet, against all odds, the Svalbard reindeer have not just survived but thrived.
"Despite the low genetic diversity, they have managed to develop a number of adaptations to life in the High Arctic," Dussex revealed.
These adaptations include smaller size, shorter legs, the ability to digest mosses when lichens are scarce, and the remarkable capability to adjust their circadian rhythm to the extreme seasonal variations on Svalbard.
Population Bottleneck
The survival story of the Svalbard reindeer took an interesting twist in the early 1900s when they teetered on the brink of extinction due to excessive hunting.
This period of near-extinction, where only a few individuals with unique genetic variants survived, is known as a "bottleneck" in population biology.
Astonishingly, this bottleneck and their inbreeding did not spell doom for the Svalbard reindeer.
"In this case, we are dealing with a population that suffers from a high degree of inbreeding, which is usually bad news for a small population," said Michael D. Martin, a professor at NTNU's Department of Natural History.
But inbreeding can also help a population to get rid of harmful mutations, a phenomenon technically called 'purging,'" Martin added.
What Lies Ahead for the Svalbard Reindeer?
While the Svalbard reindeer's ability to adapt and thrive in extreme conditions is a testament to nature's resilience, there is a looming question: can they withstand the rapid changes brought about by climate change?
According to a study, the Arctic has warmed roughly four times faster than the rest of the world in the last 43 years. This suggests that the Arctic is about 3°C warmer than in 1980.
As the Arctic warms at an alarming rate, the adaptations that allowed the Svalbard reindeer to flourish in the frigid north may fall short.
Stay posted here at Tech Times.
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