1. A method of classifying a biological element comprised of biological subelements into a functional family, wherein each family is represented by a cluster of data points around a common frequency characteristic of a time-frequency transform, the method comprising the steps of: a) converting a symbolic representation of a sequence of biological subelements of the biological element to a numeric representation of that sequence; b) performing a time-frequency transform on the numeric representation; c) identifying a cluster of data having a common frequency characteristic in the time-frequency domain, thereby to identify the biological element in the functional family corresponding to that cluster of data points.