I am Legend

This is a link to the wikipedia page describing the 1954 book I Am Legend by Richard Matheson. I thought it was interesting that in the original book the zombies are created by a pandemic of bacteria, while in the movie with Will Smith, the zombie problem arises from genetic mutation, a genetic mutation that was initially thought to be beneficial as a cure for cancer. This aspect of genetic mutation must have been added to make the zombie problem more believable for modern audiences.