1. A computer system, comprising: one or more computation devices, wherein the one or more computation devices comprise one or more of: a processor, one or more cores in a second processor, or another type of device configured for computation; memory configured to store a program module, wherein, when executed by the one or more computation devices, the program module causes the computer system to perform one or more operations comprising: accessing a stored set of genetic features for individuals in a group of individuals and associated trait information; determining patterns of occurrence of combinations of the set of genetic features for the individuals based on the set of genetic features and a set of mathematical interactions, a pattern of occurrence of a combination corresponding to patterns of occurrence of at least a pair of genetic features for the individuals and a mathematical interaction; calculating statistical associations between the patterns of occurrence of the combinations and a pattern of occurrence of the trait information for the individuals, a statistical association corresponding to the pattern of occurrence of the combination and the pattern of occurrence of the trait information; performing second operations at different statistical-association threshold values until a noise-floor criterion is valid, wherein the second operations comprise: selecting a given subset of the combinations having statistical associations that are larger than a given statistical-association threshold value; determining one or more given aggregate properties of the given subset of the combinations, wherein the one or more given aggregate properties comprise given numbers of occurrences of the genetic features in the given subset of the combinations; computing a given ranking of the genetic features based on the determined one or more given aggregate properties; and assessing whether the noise-floor criterion is valid by comparing the given ranking to at least another ranking of the genetic features based on another instance of the one or more aggregate properties corresponding to another statistical-association threshold value to determine whether at least a portion of the given ranking and the other ranking are approximately stable; and identifying a subset of genetic features in the set of genetic features based on one or more final aggregate properties of at least a final subset of the combinations corresponding to at least a final statistical-association threshold value where the noise-floor criterion is valid, wherein the one or more final aggregate properties comprise numbers of occurrences of the genetic features in the at least the final subset of the combinations.