How old is the wolf species

The clearest delimitation is visible in the network based on alignment A Figure S1. Much less resolution was displayed in the other networks, since these were based on shorter alignments Figures 2 , 3. Even though the two haplogroups identified by Leonard et al.

This supports the indications from previous studies of a past extended diversity that was lost, at least in Europe, Siberia and Alaska, and which overlapped only to a limited extent with that seen in modern wolves. Temporal changes within the ancient samples were also apparent in the network of alignment C, where the constellations of ancient haplotypes are fairly delimited and haplotype continuity is decreasing through time Figure 3.

Among the ancient samples, a decline in haplotype numbers is observed at the beginning of the Holocene. This could reflect a bottleneck event or the lack of available samples from North American wolves in the Holocene Figure 3 ; 10—1 kyrs BP. Figure 2. Median joining network analysis for wolf haplotypes based on alignment B excluding indels bp and including a temporal comparison Late Pleistocene vs.

Haplotypes ellipses are separated by the number of mutational steps indicated by continuous lines and black ellipses represent missing haplotypes. Figure 3. Median joining network analysis for ancient wolf haplotypes HT identified for alignment C as well as all modern samples trimmed to match this alignment excluding indels; 57 bp.

Temporal comparisons of five consecutive time periods are presented covering the Late Pleistocene and Holocene. Number of mutational steps is indicated by continuous lines, black ellipses represent missing haplotypes. Colors correspond to geographical region see Figures 1 , 2. We found substantial evidence for a population bottleneck taking place in North America. For Eurasia, none of the three models constant, bottleneck , or split gained substantial support by model choice over the other.

This emphasizes the importance of dense sampling of wide-spread species in order to cover as much of the genetic variation as possible. Most new haplotypes were discovered in Siberia and China, which together with Europe contained the highest degree of diversity Table 1. Samples from these regions were also widely distributed in the networks and the phylogeny Figures 1 — 3.

Despite their remote location, the arctic wolves from Greenland did not represent a new or unique haplotype. Instead they all belonged to a haplotype Clu53 shared with other North American wolves and placed within the largest of these clades II suggesting that the maternal lineage of contemporary Greenland wolves has its origin in North America.

This is well in agreement with a proposed pattern of recurring colonization of Greenland by wolves from the Canadian arctic i. Much like the polar bear, the evolutionary history, and possible genetic differentiation of this subspecies could better be explored with genomic markers Hailer et al. The network analyses demonstrated that the ancient wolf samples constitute a significant proportion of the global diversity, which was almost entirely lost in North America, and severely diminished in Europe.

It is also apparent that all ancient samples fall within one half of the phylogeny and the network based on alignments A and B, thereby constituting lineages different from most of the contemporary wolves. Accordingly, all ancient haplotypes defined in alignment A were unique and not found within the modern dataset Figure S1. Both of the ancient samples from Siberia analyzed here Clu and Clu grouped among the other ancient wolves, confirming this pattern. A division of both contemporary and ancient wolves into two distinct haplogroups, as described in previous studies Leonard et al.

However, the pattern of ancient haplotypes disappearing in North America supports a turnover taking place there, which is in line with Leonard et al. Instead of detecting an extinction-replacement, the coalescent simulations provided a significant support for a bottleneck scenario taking place around the Pleistocene-Holocene boundary around 12, years ago in North America. In contrast, the lack of support for any of the simplified population histories for Eurasia may suggest a more diverse demographic history across this landmass, where the process leading to the decline of many of the ancient lineages might have been slower and more ambiguous.

In Europe, several recent studies have indeed found discrepant results for the population dynamics in wolves, where mitochondrial data indicated a recent increase in population size, whereas data based on nuclear SNPs instead showed a continuous decline, starting already in the Late Pleistocene Pilot et al. The latter dataset also suggested a similar pattern of decrease in North America Pilot et al. One aspect to keep in mind in relation to the proposed demographic changes is the uneven temporal and geographical distribution of ancient wolf samples, on which this and other studies are based.

We are thus lacking data on the ancient diversity of Asian wolf populations, which precludes reliable assessments of demographic events and phylogeography across much of this continent. Our coalescent simulations are also inherently limited by the number of sequences as well as variation within and between models that are tested, and can only be evaluated in light of these specific factors. The paleontological record implies a continuous presence of wolves across the northern hemisphere stretching through the last glacial maximum LGM , and shows little indication of the wolf's range being significantly restricted during glaciations Sommer and Benecke, ; Leonard et al.

In North America, the continental ice sheets formed an effective barrier during long time periods, which most likely isolated southern wolf populations from those in Beringia Alaska; Leonard et al. This is also supported by clear morphological differences observed between Beringian wolves and wolves south of the ice sheets during the Late Pleistocene Leonard et al.

In Eurasian wolves, there are few decisive signs of population structure shaped by glacial refugia during the LGM, something which has been suggested for other mammals Taberlet and Bouvet, ; Stewart et al.

One example is the Italian wolf population, which is clearly distinct, and positioned close to the ancient wolves in the phylogeny. Other studies have estimated that this population was in fact isolated for thousands of generations in the Italian Peninsula Lucchini et al. However, more recent factors like hunting and restrictions to gene flow might also have severely decreased genetic diversity and caused genetic drift in this population Valdiosera et al.

Interestingly, genomic data from a recent study revealed genetic distinctiveness in wolves from both from the Italian and the Iberian peninsulas, explaining it as a result of isolation during the LGM vonHoldt et al. In order to shed more light on the genetic singularity of these populations, additional analyses of ancient samples would be needed.

One behavioral feature of the wolf which can potentially counter the establishment of long term phylogeographic structures is its dispersal capabilities. Wolves are extremely mobile and migration of several kms is common for both sexes Fritts, ; Mech et al. Another aspect of detecting population structures from genetic diversity is the type of genetic material studied, for instance autosomal vs.

A previous study on modern wolves based on a short bp CR sequence failed to detect clear population structures globally Vila et al. A number of recent studies analyzing mitochondrial genomes and autosomal SNPs of wolves worldwide have been more successful in this respect, finding significant differentiation between wolf populations of Europe, Asia, North America, and even within the continents vonHoldt et al.

Although restricted to the mitochondrial control region, our analyses did recover most of the same clusters and clades that were revealed from datasets of almost complete mitochondrial genomes Thalmann et al. However, despite the larger sample set, the comparably shorter sequence length used precluded confirmation of the same topology with equally substantial support.

The clades within the phylogeny should thus be interpreted with some caution, given their generally low support values. In contrast to phylogenies based on mitochondrial markers, a phylogeny based on autosomal SNPs differed in a significant way, as it displayed distinct geographical patterns, where the most basal split separated wolves in North America from those in Eurasia Fan et al. The discrepancy of this result compared to ours and to the phylogenies based on mitochondrial markers in general Thalmann et al.

A likely explanation is that mitochondrial lineages in wolves can be highly affected by the animal's wide dispersal as well as incomplete lineage sorting, which has to be considered when results from these different methods are compared Funk and Omland, ; Toews and Brelsford, Discordance is in fact a general problem when comparing genetic studies on wolves, even when similar markers are used.

We specifically encountered this dilemma when searching for published data that often did not overlap with our sequences. In order to facilitate comparisons of data and avoid the confusion of novel haplotype names, a harmonization of methods, and markers is necessary de Groot et al. With the use of autosomal markers, some studies have also managed to discern patterns on more restricted geographical scales Weckworth et al. In many instances these population patterns, which have shown little correlation with geographical barriers, have instead been explained by ecological specializations in different populations Carmichael et al.

A pattern of differentiation along a North-South axis has for instance been observed in European wolves Stronen et al. These findings are much in concordance with the proposed causes to the turnover seen in North America, explained in terms of a population of larger and more specialized wolves going extinct along with other megafauna Leonard et al.

Sampling of modern wolves has several limitations, mainly due to practical difficulties, decreasing numbers, and local wolf populations going extinct. Recent bottlenecks have also hampered the ability to achieve an overview of the phylogeography of the past.

However, remains of wolves are common both in paleontological and historical collections, and to improve our understanding of the population dynamics of the gray wolf, analyses of more samples are needed to cover both the distant as well as the more recent past.

YC performed the Bayesian simulations. All authors contributed to the interpretation of the results and took part in writing the manuscript. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The authors would like to thank everyone contributing with samples for this study. Arman Ardalan is especially acknowledged for helping with the Iranian samples, as is Sofie Wagenius for help with identifying Late Pleistocene wolf remains, and Kristian Gregersen for providing access to Greenlandic specimens. Lastly, we thank Prof. Thomas P. Gilbert for his financial support of M-HS's work. The findings and conclusions in this article are those of the author s and do not necessarily represent the views of the U.

Fish and Wildlife Service. Aggarwal, R. Mitochondrial DNA coding region sequences support the phylogenetic distinction of two Indian wolf species. Anderson, C. Serial SimCoal: a population genetics model for data from multiple populations and points in time. Bioinformatics 21, — Andersone, Z. Hybridisation between wolves and dogs in Latvia as documented using mitochondrial and microsatellite DNA markers.

A federal Endangered Species Preservation Act offered limited protection for wolves on federal lands. In Europe, the Argos system was developed to monitor the environment and track highly mobile animals. The technology, still in use today, involves a device that sends signals to satellite receivers in polar orbits. The device, attached to the animal with glue, suction cups or bolts, allows researchers to capture acoustic information, daily GPS locations, and chemical information such as pesticide use.

Some devices even include a digital camera. Ways of studying and tracking wild populations evolved as new technology was developed and GPS becomes more commercially viable.

A female wolf named Phyllis was outfitted with a radio collar and her movement followed by researchers. When signals were sent from the same place over a period of two weeks scientists assumed she was whelping giving birth and staying near a den. This type of federal action spurred hope among those concerned with the conservation of the species. It also provoked fear, resentment, and even lawsuits among people concerned about their livestock and livelihoods.

Multiple lawsuits were filed by ranchers and environmental groups at odds with each other over the status of wolves. An unusually emotional and heated discourse erupts over the conservation of an animal. The significant amount of media attention, policies, laws, and public opinion surrounding this species is a testament to the iconic stature the species holds. The attention also reflects a broader discourse about predator management, animal-human conflict, and the value our society places on wilderness conservation.

An estimated 65, wolves live in North America, mostly concentrated in Canada and the U. Fish and Wildlife Service continues to protect the Mexican gray wolf Canis lupus baileyi , a struggling sub-species indigenous to the Southwest. The agency has proposed to remove the gray wolf from the list of threatened and endangered species. We encourage older students to further review the issues surrounding this species, and specifically to look at policies, laws and science—both proposed and in effect—in order to more fully grasp conservation status of this national icon.

I realized then, and have known ever since, that there was something new to me in those eyes—something known only to her and to the mountain. I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves would mean hunters' paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view. Not only are there tremendous differences in both individual and pack personalities, but each displays a surprising range of behaviors depending on what's going on around them at any given time.

No sooner will a young researcher think, 'That's it, I've finally got a handle on how wolves respond in a particular situation,' than they'll do something to prove him at least partially wrong. Those of us who've been in this business for very long have come to accept a professional life full of wrong turns and surprises.

Clearly, this is an animal less likely to offer scientists irrefutable facts than to lure us on a long and crooked journey of constant learning. The land itself was a desolation, lifeless, without movement, so lone and cold that the spirit of it was not even that of sadness.

There was a hint in it of laughter, but of laughter more terrible than any sadness—a laughter that was mirthless as the smile of the Sphinx, a laughter cold as the frost and partaking of the grimness of infallibility. It was the masterful and incommunicable wisdom of eternity laughing at the futility of life and the effort of life.

It was the Wild, the savage, frozen-hearted Northland Wild. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited. Caryl-Sue, National Geographic Society. For information on user permissions, please read our Terms of Service.

Relatively late in the evolutionary history of miacids came the appearance of the first canid Cynodictis , one of these was called the dawn-wolf , this creature had a long body and looked like a enlongated fox, it could live and climb in trees, it was also thought to possibly related to feline species.

Some authorities believe that canids originated in North America and then spread to Asia and South America, while others ascribe that a small type of wolf crossed into siberia from alaska, where it eventually developed into the larger, present-day grey wolf. The grey wolf then migrated to North America, where it populated what is now Canada and the United States, except for the southeastern section of the latter country. Still Others believe that the dog family originated in North America, migrated to Asia, and then returned.

Wolf ancestors began to develop in the Paleocene, about sixty million years ago. By the Miocene, about twenty million years ago, canines and felines had branched into two separate families. In one ancestor of the wolf, Tomarctus , the fifth toe on the hind leg became vestigal and is evidenced today by the dew claw on both wolves and dogs.

Research of wolf history by Robert Wayne at the University of California suggests that a number of wolflike canids diverged from a common ancestor about two to three million years ago. The first gray wolf, Canis Lupis , probably appeared in Eurasia sometime in the early Pleistocene period about a million years ago.

Around , years ago, it is though to have migrated to North America. The Dire Wolf, Canis Dirus , larger and heavier than the gray wolf, evolved earlier and the two co existed in North America for about , years. As prey became extinct around 16, years ago due to climatic change, the dire wolf gradually became extinct itself.

Around 7, years ago the gray wolf became the prime canine predator in North America. In technical terms, the new findings mean dire wolves may need a new genus name to indicate they are no longer part of the genus Canis , to which gray wolves belong. These predators became specialized in hunting camels, horses, bison and other herbivores in North America over millions of years.

As those prey sources disappeared, so did the dire wolves. Nor did dire wolves leave a genetic legacy beyond the decaying DNA in their ancient bones. Although canids such as wolves and coyotes often create hybrids, dire wolves apparently did not do so with any other canids that remain alive today.

Perri, Mitchell and their colleagues found no DNA evidence of interbreeding between dire wolves and gray wolves or coyotes. By 13, years ago, dire wolves were facing extinction. Preserved genes have shown that dire wolves and their ancestors were top dogs in the Americas for more than five million years—and the early chapters of their story are waiting to be rewritten.

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