One of the least studied of all canids is the pale fox (Vulpes pallida). It is native to the Sahel, a region in North Africa that lies between the Sahara and the savannas.
It was always assumed that the pale fox was a true vulpine fox, perhaps closely related to the fennec, which lives just to its north in the Sahara proper.
However, a new study out of the Russian Institute for Cytology has revealed something truly shocking. Not only is the pale fox not a true fox, it actually is much more closely related to the black-backed and side-striped jackals than to any other canid.
Researchers traveled to Senegal and Mali and spent eighteen months live trapping the little foxes. Initially, the researchers thought it would be quite difficult to capture enough specimens for the study, but it turns out that pale foxes are very easy to trap. All it took was just a bit of sheep fat and marten glands to lure the foxes into live cage traps.
The researchers were able to capture 21 in Senegal and 17 in Mali. They took blood samples from the foxes, which were sent to St. Petersburg.
At St. Petersburg, the researchers were able to extract good quality samples of mitochondrial DNA, which were then compared to the mitochondrial DNA of other extant canids. Mitochondrial DNA is inherited from the mother’s line, and it can be used to determine evolutionary relationships among various species.
The studies found that the samples of mitochondrial DNA of pale foxes most closely matched the black-backed and side-striped jackals than any of the fennecs, red foxes, and Rüppell’s foxes in the study. They were also similar to wolves, domestic dogs, and golden jackals.
Dr. Igor Iljin, head researcher on the study, says that the findings are truly a surprise.
“What we have found is that the pale fox is actually a jackal that has evolved into roughly the same niche as a desert fox. Our analysis of the mutation rates suggest that the pale fox only split off from the black-backed/side-striped jackal clade about 3.5-4 million years ago.”
Because black-backed jackals have been around in their present form for around 2-3 milion years, Iljin thinks that the pale fox evolved from jackals that became stranded in the Sahel around that same time period. Over time, they adapted to a more specialized diet of insects and small rodents. They also became significantly smaller to adapt to such a nutrient-poor diet.
Because the pale fox resembles the fennec in its ecology and morphology, it was assumed that these two species would be the most closely related.
However, this study shows that the pale fox’s similarity to the fennec are the result of convergent evolution.
“Just as convergent evolution produced a placental wolf in Eurasia and a marsupial wolf in Australia, it has also produced two very similar arid-zone “foxes” in Africa,” Dr. Iljin concludes.
Further, Dr. Iljin strongly suggests that we stop calling the pale fox by that name:
“From now on, it should be referred to as the ‘pale jackal,’ and its scientific name should be updated to Canis pallida. Of course, we are aware that that the exact position of this endemic African clade of canids may or may not be properly classified within Canis, and if that were to change, we would expect the pale jackal to be placed with its closest relatives.”
So there we have it. What was once thought to have been a fox is actually a jackal.
DNA has found stranger things before!
So we have a new species in Canis, which was once Vulpes.
Convergent evolution hid a dog in fox’s clothing.