It is a truism among biologists that an organism's phenotype is the product of both its genotype and its environment. An organism's genotype contains the total informational potential of the individual, while its environment shapes the expression of the ge- type, influences the rate of mutation and occurrence of modifications, and ultimately determines the likelihood that the genotype (or fractions thereof) will survive into the next generation. In the relationship between host and pathogen, therefore, each forms a part of the environment of the other, mutually influencing the biology of both...

It is a truism among biologists that an organism s phenotype is the product of both its genotype and its environment. An organism s genotype contains the total informational potential of the individual, while its environment shapes the expression of the ge- type, influences the rate of mutation and occurrence of modifications, and ultimately determines the likelihood that the genotype (or fractions thereof) will survive into the next generation. In the relationship between host and pathogen, therefore, each forms a part of the environment of the other, mutually influencing the biology of both...