The bowhead whales that inhabit the vastness of the Arctic Ocean at the very top of the globe appear to have something in common with the wolves that roam the vast wildness of Alaska. All live in seemingly independent groups -- packs for wolves, pods for whales -- but new genetic research shows them to be so interrelated that there is obviously a whole lot of sex going on outside those groups.
Wildlife biologists studying the wolves of Denali National Park and Preserve broke new ground in the study of those animals more than a decade ago when extensive genetic testing led them to the conclusion the wolves of Denali are the wolves of Alaska. Up until that time, many had held to the belief that the park's long-watched Toklat pack and others represented discreet lineages. Not so, discovered world-famous wolf research L. David Mech, who headed a nine-year study with Tom Meier of the National Park Service, Layne Adams of the U.S. Geological Survey, and Bruce Dale of the Alaska Department of Fish and Game.
Wolves were regularly leaving Denali for other parts of Alaska to breed while wolves from outside the park were regularly moving in to find mates. At least one male wolf has been tracked traveling more than 1,000 miles around Alaska in search of a potential mate.
Now come scientists from the Wildlife Conservation Society, the American Museum of Natural History, City University of New York and elsewhere who looked at not just the genetics of modern bowheads but that of ancient whales and concluded they're all part of one big family -- despite an ice pack that some long thought kept them from interbreeding.
A new study that tracked the genetic patterns of bowheads over time revealed that the Arctic ice pack -- previously thought to largely prevent interbreeding between Arctic and Pacific populations -- wasn’t much of a barrier to breeding.
Part of that is due to the bowhead’s unique physiology particularly adapted to Arctic environments, “with the thickest blubber layer of any mammal and the ability to break ice 30-60 cm (almost two feet) thick” with their bony skulls, according to the study.
Ancient DNA holds clues
Tissue samples for the study came not only from modern whalers who worked with researchers but from archaeological sites used by indigenous hunters thousands of years ago. The ancient DNA, according to phys.org, revealed that the whales had apparently suffered due to climate change in the past, but it wasn't the global warming many worry about today.
"The results indicate that Arctic sea ice has not acted as a strong barrier to migration between the Atlantic and Pacific over the late Holocene as previously assumed, and that genetic diversity has been lost from eastern Canada in the period between (500 years ago) and the present,” the study said.
The result is less diversity among ancient bowhead populations and those that exist today. The study said that the likely cause of the relative lack of diversity is not likely related to recent years of drastic sea ice melt, when bowhead whales might have an easier time moving from location to location.
Instead, it theorizes that heavy whaling over the years may have contributed to a smaller genetic pool, or possibly a loss of habitat during the a previous period of cooling that occurred over several centuries. One Canadian Arctic population also saw a unique maternal lineage disappear between ancient and modern bowhead populations.
Today, several populations of bowhead whales continue to face reduced populations in the wake of heavy whaling in the late 19th and early 20th centuries. Some Alaska Native communities continue to hunt the whales as part of their traditional subsistence hunting practices.