Natural History

One of the most difficult things I’ve found to write about is the wolf subspecies Canis lupus pallipes. Some erroneously believe that this refers only to the Indian wolf, which has been proposed to be a separate species.

No.

The pallipes wolf is the wolf subspecies that ranges from the Levant to (at least) northern India. It is the larger of the two wolf subspecies native to the Middle East and is one of the likely ancestors of domestic dog.

However, there are some wolves native to the Indian subcontinent that have been found to have a very old mtDNA sequence, which has, of course, led to some speculation as to whether these might be a separate species called Canis indica.  Canis indica wolves would have been part of the pallipes subspecies, but I still don’t think it’s clear that they are separate species at all. These wolves are not morphologically distinct from other Indian pallipes, and they don’t behave differently from them either.

Keep in mind that mtDNA is just inherited maternally, and we already have a good example of a population of a species in the genus Canis in which wide variances in mtDNA occur. The  some populations of East African black-backed jackal have individuals in them that have as much as 8 percent variance within their mtDNA sequences, which is much more than the variance between the proposed Canis indica and other wolves. But no serious scholar suggests that these black-backed jackals represent separate species.

Further, no nuclear DNA studies have found any unique characteristics within Indian wolves. However, most of the studies that look at Indian wolves look at wolves from India, which may not necessarily refer to wolves with this old mtDNA sequence.  These studies have always show that Indian wolves are very closely related to those of the Middle East, which is exactly what we would expect.

And without these corroborating nuclear DNA studies, I am very skeptical that the Indian wolf truly represents a unique species. It may be that within some Indian populations of pallipes, some of the old matrilines within the wolf species have survived. That is an is in itself an interesting find, but that is all that this finding suggests. One cannot automatically assume that the discovery of this old matriline is indicative of a new wolf species, and the same goes for the unique and old matriline that was discovered in the Himalayan wolf.

The truth is that old wolf matrilines have been discovered in India and the Himalayas, and they were also recently discovered in what were once thought to be African golden jackals.  Although no nuclear DNA studies have been performed on these newly discovered “wolves,”  it is likely that these animals also are part of Canis lupus.  It would be very unusual for a hybrid origin for these “African wolves,” because if they were hybrids between golden jackals and smaller wolves that were early off-shoots of Canis lupus, they would have golden jackal mtDNA, not wolf mtDNA. It seems unlikely that female wolves would pair off with golden jackals. I don’t think anyone has ever produced evidence of golden jackals and wolves hybridizing in the wild, although pariah dogs and jackals do occasionally cross, usually from a pairing of a male dog and a bitch jackal.  Such hybrids, however, would have golden jackal mtDNA, so so one might assume that if any wild wolf/jackal hybrids ever existed, they would have jackal mtDNA.

We still need a nuclear DNA analysis of these wolves, and those of the propose Himalayan and Indian subspecies to have a clear answer.

Because of these issues, we cannot use mtDNA alone to determine species status. MtDNA just traces maternal lineages, and it is fraught with errors.  Recently, it was determined that African savanna and forest elephants are much more genetically distinct than had ever been assumed.  The original studies on African elephant mtDNA found that they split about 3 million years ago. However, a recent nuclear DNA analysis found that they actually split apart as early as 6.7 million years ago, which is about the same time that Asian elephants and woolly mammoths diverged.

So when one reads of a new species being discovered through an analysis of mtDNA, it is important to remain skeptical.

For these reasons, I do not consider the Indian wolf to be a unique species– and the same goes for the African and Himalayan wolves.

We need nuclear DNA studies before we start splitting up species.  It is just too easy to be in error using mtDNA studies, even though mtDNA is much easier to use, much easier to sequence, and much less resistant to mutation.

Mitochondrial DNA is just a part of the genome, and what analyses of it actually prove are far more narrow in scope than is often understood.

Nuclear DNA studies are much harder to perform, but they are necessary before we start divining new species from those that have long been classified.