1. An apparatus to identify one or more association variables that are associated with a phenotype, comprising: at least one processor; at least one memory; and at least one program module, the program module stored in the memory and configurable to be executed by the processor, the program module including: instructions for calculating statistical relationships between a pattern of occurrence in a group of life forms of the phenotype and patterns of occurrence in the group of life forms of pairwise combinations of biological variables in a set of biological variables of the group of life forms, wherein a given statistical relationship is between the pattern of occurrence in the group of life forms of the phenotype and a pattern of occurrence in the group of life forms of a given pairwise combination of biological variables, wherein the pattern of occurrence in the group of life forms of the given pairwise combination of biological variables is based on a pattern of occurrence in the group of life forms of a first biological variable in the set of biological variables, a pattern of occurrence in the group of life forms of a second biological variable in the set of biological variables, and a given mathematical operation, wherein the calculating includes contributions from presence and absence information in the pattern of occurrence in the group of life forms of the phenotype and presence and absence information in the patterns of occurrence in the group of life forms of the pairwise combinations of biological variables, and wherein, for each of the biological variables in the set of biological variables, the pairwise combinations of the biological variables in the set of biological variables include multiple instances of pairwise combinations; instructions for selecting a subset of the statistical relationships that exceed a statistical significance value; instructions for determining numbers of occurrences of the biological variables in the pairwise combinations of the biological variables corresponding to the statistical relationships in the subset, wherein the numbers of occurrences are other than patterns of occurrence in the group of life forms of individual biological variables in the set of biological variables and the patterns of occurrence in the group of life forms of the pairwise combinations of biological variables; and instructions for identifying one or more of the biological variables in the pairwise combinations of the biological variables as the one or more association variables based on the determined numbers of occurrences.