Biological Sciences
Andrew Storfer
Emerging Diseases Present Threat to Global Biodiversity
Download a printable pdf
Amphibians are recognized as a prominent example of a global biodiversity loss, with nearly 40 percent of all amphibian taxa threatened with extinction. What is particularly concerning is many of these declines have occurred in protected parks and reserves. Emerging diseases are a leading hypothesis for these “enigmatic” declines. A critical question is, “Why are these declines happening now?” One hypothesis is that the pathogens are new, and amphibians have not evolved defenses. An alternative is that the pathogens are old and the environment has changed, resulting in increased amphibian susceptibility or conditions that make pathogens more virulent.
At Washington State University, Dr. Storfer’s research has been focused on testing these hypotheses by investigating the extent to which tiger salamanders and an emerging pathogen (iridoviruses) are co-evolved using ecological and molecular genetic studies. Dr. Storfer’s research supports co-evolution of salamanders and viruses in some areas. However, genetic analyses of virus strains suggest that some strains have been introduced into parts of the western United States via human movement of infected salamanders used as fishing bait. Such human transport of bait salamanders may contribute to disease emergence because an introduced pathogen strain is more virulent than native strains.
Indeed, artificial disease introduction (or “pathogen pollution”) is cited as one of the most important reasons for disease emergence worldwide, yet few studies have investigated the effects of novel pathogens. Because global transport of pathogens is now possible in a matter of days, we need to predict which pathogen species will emerge on hosts outside their established geographic range and on novel host species. One group of hypotheses suggests that novel pathogens might be highly virulent on new hosts, because they have not yet evolved defenses. Alternatively, pathogens might be highly coevolved and specialized with their native hosts, making host switches less likely and reducing pathogen performance. Dr. Storfer’s current research is focused on testing these hypotheses with experiments designed to evaluate the performance of amphibian pathogens on naïve native hosts and novel host species.
Contact Information
Andrew Storfer, Ph.D.
Assistant Professor
School of Biological Sciences
Washington State University
PO Box 644236
Pullman, WA 99164-4236
Telephone: 509-335-7922
E-mail: astorfer@wsu.edu
|
