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2011 The cS ientific lC assification of Wolves: Canis lupus soupus L. David Mech USGS Northern Prairie Wildlife Research Center, [email protected]
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Mech, L. David, "The cS ientific lC assification of Wolves: Canis lupus soupus" (2011). USGS Northern Prairie Wildlife Research Center. 315. https://digitalcommons.unl.edu/usgsnpwrc/315
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4 Spring 2011 www.wolf.org ical characteristics. Thus some classifi- cation scientists (taxonomists) were “splitters” and others “lumpers.” Splitters tended to separate groups more finely, whereas lumpers tended to lump smaller groups into larger clus- ters. However, there was no objective basis for determining which approach might be correct or more informative. Scientists who classified wolves in North America were splitters. Old World scientists had pretty well recog- nized that there were 8 geograph- ically distinct races, or subspecies of wolves in Europe and Asia. However, North American scientists split New World wolves into 24 subspecies. This is how there came to be so many common names for North American wolves, for example, the eastern timber wolf, the arctic wolf, the Mexican wolf, the great plains wolf, etc. Scientifically, the subspecies or races have three parts ray wolf, timber wolf, red wolf, to their name (Example: Canis lupus eastern wolf, brush wolf, arctic baileyi, the Mexican wolf), but all the Gwolf, Mexican wolf, maned subspecies are of the same basic gray- wolf, Ethiopian wolf, etc., etc. How wolf species, C. lupus. many kinds of wolves are there? And However, wolves are great travelers. what are the differences? This is a Ear-tagged or radio-tagged wolves have really good question, and the answer is dispersed from the natal packs in getting more complicated all the time. the range of one subspecies across the Let us start by going back a few ranges of two or three other races. The years to the way science looked at current record is a wolf in Finland wolves more traditionally— before the that traveled a straight-line distance of by L. DAVID MECH days of the new field of molecular 655 miles, or 1,092 kilometers. This genetics. Molecular genetics examines potential to travel calls into question the actual DNA of animals and tries the existence of so many subspecies to classify them according to genetic with small ranges. similarities. Thus it made good biological sense Before the advent of molecular gen- when in 1995 the eminent canid etics, scientists classified wolves (and taxonomist, Ron Nowak, published other animals) based on their physical a reclassification of North American traits (morphology). With wolves, it wolves. He lumped the 24 origin- was primarily coat color and skull ally recognized subspecies of North measurements. These characteristics, American wolves into 5. In reality, of course, basically reflect the animal’s whether one recognizes 24, 5 or 3 genetics but only indirectly. North American races of wolves, a One major problem with this older wolf is a wolf is a wolf. Science has approach is that there is a certain not demonstrated any basic behavioral amount of judgment in assessing phys- differences among any of these races,
International Wolf Spring 2011 5 nor has any scientist even proposed South America is not really a wolf; it dies, however, examine the actual DNA that such behavioral differences exist is still a member of the Canidae, or of animals and thus potentially reveal among wolf races. dog family, but it is not part of the wolf their true genetic relatedness. These So far I have only been discussing branch of that family, despite its genetic studies use chemicals to amplify the gray wolf, Canis lupus, which is common name. The Ethiopian wolf the DNA found in blood, hair, skin the most widespread wolf worldwide. (Canis simensis), on the other hand, or even intestinal cells that slough off The other type of North American wolf may actually be a wolf. Traditionally in feces. A special, high-tech machine that has traditionally been recognized scientists thought the animal was a then presents a sort of photo of parts of is the red wolf, Canis rufus, of the jackal (similar to a coyote), but recent the DNA that can be examined. southeastern United States. Scientists genetic study seems to indicate it is a Problems with the molecular-gene- still disagree about the true identity of wolf. Some scientists, however, still tics approach arise, however, from the red wolf. Some think the red wolf think it is a type of jackal. several sources. First the field is rela- is a cross between the gray wolf and So much for the less complex tively new and thus still being tested the coyote (Canis latrans—also called aspects of wolf taxonomy. The com- by the usual scientific processes like the “brush wolf” in some places). plications have arisen because of replication, competing interpretation Others have proposed that the red wolf the relatively new field of molecular and the continuing addition of new is just another race of gray wolf, while genetics. Molecular-genetic studies are information. In addition, the issue of still others believe the red wolf is a a powerful and valuable tool to add subjectivity or personal interpretation valid entity of its own. incisive information about the related- of the data is still a problem. Related- From a worldwide perspective, we ness of one group of wolves to others. ness itself is a matter of degree. Except must also consider both the maned Mere appearances can be deceiving for twins or other multiple individuals wolf and the Ethiopian wolf. The as the similarities between fish and arising from the same egg and sperm, maned wolf (Chrysocyon brachyurus) of whales attest. Molecular-genetics stu- every individual is genetically unique. Greg Koch
Red wolf David C artier
Coyote
6 Spring 2011 www.wolf.org Every wolf pack is genetically distinct on a larger scale, and every wolf popu- lation is distinct on a still larger scale, Are the wolves with the two types etc. Thus where does one draw a line to group genetically similar entities as of DNA the same species? special enough to call them different? Furthermore, how much weight should be given to results of various genetic tests relative to physical traits such as skull measurements that have What if other genetics tests show a genetic basis but whose genetics have not been examined? For example, with they differ, but the animals show one genetic test, some 38 percent of 88 Minnesota wolves tested have a kind of DNA the same as, or similar to, no physical or behavioral differences that of coyotes. This particular type of DNA has nothing to do with any phys- and can freely interbreed? ical or behavioral trait. Wolves with this coyote-like DNA mate with those having wolf DNA and form packs like all the other wolves in the population. They look and act like all the other wolves. Are the wolves with the two types of DNA the same species? What if other genetics tests show they differ, skulls of red wolves can be distin- What does all this mean in terms but the animals show no physical or guished from those of eastern wolves of understanding basic wolf biology behavioral differences and can freely and of Minnesota wolves. and behavior? Actually not much. The interbreed? What if the two types also If this all seems confusing, that’s aphorism “a wolf is a wolf is a wolf” is inhabit different but overlapping areas? because it is. And adding to this con- highly appropriate in this regard to The last is precisely the case with a fusion is the fact that both the red wolf anyone except the taxonomist. proposed new species of wolf called and the eastern wolf can and do Regardless of what they are called or the eastern wolf (Canis lycaon). This hybridize with coyotes, but there’s no what differences the current genetic wolf lives from far southeastern Canada record of the gray wolf of western testing shows, wolves throughout the west to southwestern Ontario, northern Canada and Alaska interbreeding with world are pretty much the same in Minnesota and Manitoba and is coyotes. (The experiment has never basic appearance and behavior. The currently referred to as the “eastern been tried in captivity.) The much strong implication here is that when wolf.” In northern Minnesota and in larger size of the eastern coyote it comes to the great majority of the adjacent Ontario, those wolves live compared to all other coyotes is a wolf genome that codes for basic wolf closely and mate with wolves whose reflection of these interactions. Also appearance and behavior—the DNA DNA (on this particular test) is the the fact that the eastern wolf and the that has not been tested—gray wolves same as those in Alaska and northwest red wolf can hybridize with coyotes are essentially all the same. As to the Canada. However, the eastern wolf has may be further evidence the three races or subspecies of gray wolves, or been proposed as a separate species. evolved together in North America or the proposed new species, time and Not only that, but also some of the at least are closely related. much more study will tell. Meanwhile, genetic tests indicate that the eastern Recently geneticists in India dis- the classification of wolves to most wolf evolved in North America, along covered that three genetically distinct members of the public will remain a with the coyote, whereas the gray wolf populations of wolves lived adjacent mystery and an enigma probably best evolved in Asia. Furthermore, the to each other with no physical barriers embodied in the not-so-scientific eastern wolf genetics examined were and no apparent interbreeding. The name, Canis lupus soupus. n identical to those of the red wolf. geneticists proposed that two of these So is the eastern wolf the same as types be considered new species. L. David Mech is a senior research the red wolf? If so, does the red wolf However, the scientists presented no scientist for the U.S. Geological Survey cross with the gray wolf in Minnesota? data or claim that these animals dif- and founder and vice chair of the That’s what this reasoning and those fered physically or behaviorally. Before International Wolf Center. He has tests imply. There is a hitch, however. the scientific community accepts new studied wolves for 50 years and published several books and many articles on them. The hitch is that the red wolf does species designations, it usually requires He is also a member of the International not look like Minnesota wolves, and additional research and information. Wolf Advisory Committee.
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