Nearly six years after the discovery of a catastrophic fungal infection that's decimating bat populations in the U.S. and Canada, scientists have concluded that the disease is primarily transmitted by highly social bats. But just because scientists have a better handle on how bats spread the disease doesn't mean there's good news. If anything, the discovery is leading scientists to conclude that white-nose syndrome will likely result in the outright extinction of certain bat populations.
A single disease usually can't wipe out an entire species. Because virtually every organism exhibits a wide array of variation (random mutations) in its populations, there's always a good chance that some members will survive a blight and pass on those characteristics to surviving members. Even if the disease afflicts 99% of a population, there's still a good chance that the species can eventually survive.
But not in all cases, it turns out. Some diseases, it would appear, are so nasty and so thorough in their infestation that certain populations run the risk of being wiped out completely.
Take Colony Collapse Disorder, for example. Early last month we reported on how the Deformed Wing Virus (DWV) is affecting honey bee populations by piggybacking on mites. DWV works in such a way that, once it hits a colony, it infects 100% of the bees; the entire hive consequently collapses. And as it spreads from colony to colony, entire geographic regions completely lose their ability to host honey bee populations.