Long‐term endemism of two highly divergent lineages of the amphibian‐killing fungus in the A tlantic F orest of B razil

The recent global spread of the amphibian‐killing fungus [ B atrachochytrium dendrobatidis ( Bd )] has been closely tied to anthropogenic activities; however, regional patterns of spread are not completely understood. Using historical samples, we can test whether B d was a spreading or endemic pathogen in a region within a particular time frame, because those two disease states provide different predictions for the regional demographic dynamics and population genetics of B d . Testing historical patterns of pathogen prevalence and population genetics under these predictions is key to understanding the evolution and origin of B d . Focusing on the A tlantic F orest ( AF ) of B razil, we used q PCR assays to determine the presence or absence of B d on 2799 preserved postmetamorphic anurans collected between 1894 and 2010 and used semi‐nested PCR s to determine the frequency of r RNA ITS 1 haplotypes from 52 samples. Our earliest date of detection was 1894. A mean prevalence of 23.9% over time and spatiotemporal patterns of B d clusters indicate that B d has been enzootic in the B razilian AF with no evidence of regional spread within the last 116 years. ITS 1 haplotypes confirm the long‐term presence of two divergent strains of B d ( B d GPL and B d‐Brazil ) and three spatiotemporally broad genetic demes within B d GPL , indicating that B d was not introduced into southeast B razil by the bullfrog trade. Our data show that the evolutionary history and pathogen dynamics of B d in B razil is better explained by the endemic pathogen hypothesis.