The island fox may only weigh a little over two pounds when full-grown, but even this is not the most surprising aspect about these foxes. According to this scientific journal, researchers have discovered that the island foxes are nearly identical, genetically speaking. Robert K. Wayne, a geneticist at the University of California, has been studying the foxes since 1990 trying to understand how these foxes are able to thrive, especially considering one island fox community has a record for the least genetic variation in a sexually reproducing species. After sequencing the genomes from each of the six subspecies, the DNA was found to be virtually identical. There are a number of possibilities as to how these foxes have been thriving for thousands of years, such as being the top predator without exposure to inbred difficulties and the genes being programmed to be switched on and off, called epigenetics.
This fox phenomenon is very intriguing, especially since even the scientists who have been researching this topic for nearly 30 years still do not know exactly why or how these foxes are able to thrive how they are today. Another interesting aspect of this article was the option to interbreed the subspecies in order to increase their genetic diversity. There was a promising instance in which Florida panthers interbred with a Texas subspecies in which the new genes helped the Florida population to grow. However, I would have to agree with Dr. Wayne in which he would not advise this "genetic rescue" unless there was strong scientific evidence that the low genetic variation was significantly hindering the fox's populations.
The original article can be found here.