The extinction of many large mammals at the end of the Ice Age may have packed an even bigger punch than scientists have realized. To the list of victims such as woolly mammoths and saber-toothed cats, a Smithsonian-led team of scientists has added one more: a highly carnivorous form of wolf that lived in Alaska, north of the ice sheets.
Wolves were generally thought to have survived the end-Pleistocene extinction relatively unscathed. But this previously unrecognized type of wolf appears to have vanished without a trace some 12,000 years ago.
The study, which will be published in the June 21 online issue of Current Biology, combined genetic and chemical analyses with more conventional paleontological study of the morphology, or form, of the fossilized skeletal remains. This multifaceted approach allowed the researchers to trace the ancient wolves’ genetic relationships with modern-day wolves, as well as understand their role in the ancient ecosystem.
“Being able to say all of those things—having a complete picture—is really unusual,” said lead author Jennifer Leonard, a research associate with the Smithsonian Genetics Program, and currently at Uppsala University in Sweden.
The researchers extracted mitochondrial DNA from the fossil wolf bones preserved in permafrost and compared the sequences, called haplotypes, with those of modern-day wolves in Alaska and throughout the world. The fossils showed a wide range of haplotypes—greater in fact than their modern counterpart—but there was no overlap with modern wolves. This was unexpected.
“We thought possibly they would be related to Asian wolves instead of American wolves because North America and Asia were connected during that time period. That they were completely unrelated to anything living was quite a surprise,” Leonard said.
The result implies that the Alaskan wolves died out completely, leaving no modern descendents. After the extinction, the Alas