The Key to Tasmanian Devil Survival? Being Less Aggressive
By Jill Harness
Though they're delightfully adorable, Tasmanian devils don't have a reputation for being sweet and cuddly (just look at that Taz on Looney Tunes!). But according to a new study, evolving to be less ferocious might be the only thing that could keep them from going extinct.
Devil Facial Tumor Disease (DFTD) causes tumors to grow around an infected animal's mouth and face, eventually leading to starvation. The disease has been wiping out the species since the first official case was described in 1996. DFTD is spread primarily by biting, and researchers have discovered that the more often one of the creatures is bitten, the less likely he is to have contracted the virus.
It's precisely the opposite of what they expected to find. It means that the alpha males, who get bitten the least, are most likely to catch DFTD, and those at the bottom of the pack, the least aggressive creatures that get bitten the most often, are the least likely to contract the disease. "In most infectious diseases there are so-called super-spreaders, a few individuals responsible for most of the transmission," said Dr. Rodrigo Hamede of the University of Tasmania, the lead author of the study. "But we found the more aggressive devils, rather than being super-spreaders, are super-receivers." This is because, Hamede says, "they bite the tumours of the less aggressive devils and become infected."
The key to saving the species may be identifying less aggressive members of packs and introducing them into selective breeding programs, with the ultimate goal of making a less ferocious Tasmanian devil that will consequently be less likely to contract DFTD.
Of course, the question remains: If you breed out one of the most defining characteristics of a species, are the resulting creatures still part of that species, or are they something new?