Featured Research

from universities, journals, and other organizations

Ice Age Extinction Claimed Highly Carnivorous Alaskan Wolves

Date:
June 22, 2007
Source:
Smithsonian
Summary:
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, scientists have added one more: a highly carnivorous form of wolf that lived in Alaska, north of the ice sheets.

Photographs of Pleistocene wolf skulls from Rancho La Brea, California (above) and Alaska (middle). Bottom panel shows overlay of the outlines of the two skulls illustrating that although they are the same length, their shape is different-the wolf skull from Alaska is wider, and therefore those wolves had greater biting power.
Credit: Blaire Van Valkenburgh, University of California, Los Angeles

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 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 Alaskan habitat was probably recolonized by wolves that survived south of the ice sheet in the continental United States, Leonard said.

The ancient Alaskan wolves differed from modern wolves not only in their genes, but also in their skulls and teeth, which were robust and more adapted for forceful bites and shearing flesh than are those of modern wolves. They also showed a higher incidence of broken teeth than living wolves.

"Taken together, these features suggest a wolf specialized for killing and consuming relatively large prey, and also possibly habitual scavenging," Leonard said.

Chemical analyses of the bones back up this conclusion. Carbon and nitrogen isotope values of the Alaskan wolf bones are intermediate between those of potential prey species--mammoth, bison, musk ox and caribou--suggesting that their diet was a mix of these large species.

The cause of Pleistocene extinction (called the "megafaunal" extinction because of the large size of many of its victims) is controversial. It has been variously blamed on human hunting or climate change, or on a combination of factors as the Ice Age waned.

For the specialized Alaskan wolves, the story is perhaps less complicated. "When their prey disappeared, these wolves did as well," Leonard said. But the results of this study also imply that the effects of the extinction were broader than previously thought. "There may be other extinctions of unique Pleistocene forms yet to be discovered," she added.

This research will be published in the June 21 online issue of Current Biology.

Authors: Jennifer A. Leonard, Genetics Program/Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, and Uppsala University, Sweden; Carles Vilà, Uppsala University; Kena Fox-Dobbs, University of California, Santa Cruz; Paul L. Koch, University of California, Santa Cruz; Robert K. Wayne, University of California, Los Angeles; Blaire Van Valkenburgh, University of California, Los Angeles.


Story Source:

The above story is based on materials provided by Smithsonian. Note: Materials may be edited for content and length.


Cite This Page:

Smithsonian. "Ice Age Extinction Claimed Highly Carnivorous Alaskan Wolves." ScienceDaily. ScienceDaily, 22 June 2007. <www.sciencedaily.com/releases/2007/06/070621123444.htm>.
Smithsonian. (2007, June 22). Ice Age Extinction Claimed Highly Carnivorous Alaskan Wolves. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2007/06/070621123444.htm
Smithsonian. "Ice Age Extinction Claimed Highly Carnivorous Alaskan Wolves." ScienceDaily. www.sciencedaily.com/releases/2007/06/070621123444.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) — West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) — Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) — The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) — A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins