A single physical link can have multiple prefixes assigned to it. In that environment, end hosts might have multiple IP addresses and be required to use them selectively. RFC 3484 defines default source and destination address selection rules and is implemented in a variety of OSs. But, it has been too difficult to use operationally for several reasons. In some environments where multiple prefi...

Natural selection acts on virus populations at two distinct but interrelated levels: within individual hosts and between them. Studies of the evolution of virulence typically focus on selection acting at the epidemiological or between-host level and demonstrate the importance of trade-offs between disease transmission and virulence rates. Within-host studies reach similar conclusions regarding ...

Pathogens and parasites can be strong agents of selection and often exhibit genetic specificity for individual host strains. Here we use a simple host–pathogen model to explore the consequences of host–pathogen specificity for selection on pathogen infectiousness and lethality. Pathogens that can transmit themselves more readily from host to host should have a clear reproductive advantage, as s...