Do ancient behaviors increase host exposure to lethal pathogens?

Numerous factors, such as global environmental change, habitat destruction, introduced species, chemical pollution and diseases appear to be contributing to amphibian population declines.  Moreover, many amphibian species appear to behave in ways and have life history characteristics that, under today’s ecological conditions, seem to be placing them in jeopardy, especially with regard to being exposed to pathogens.  Such behaviors and ecological attributes were molded over evolutionary time under various selection pressures acting upon amphibians in a variety of ways. Assimilating evolutionary principles into our knowledge of the ecological processes associated with the role of pathogens in amphibian population declines will allow us to better understand the decline phenomenon. Some important considerations are: 1) evolution is limited by historical constraints; 2) not all evolution is adaptive; 3) adaptations are often compromises; 4) evolution can only alter existing variations and 5) evolution takes time.