COMPARATIVE-STUDIES OF RNA - INFERRING HIGHER-ORDER STRUCTURE FROM PATTERNS OF SEQUENCE VARIATION

RNA structural chemistry and evolutionary biology, long considered dis parate fields of study, are the topics of this review. Evolution trans cends all of the sciences, adding a dimension that enriches every scie nce it touches, and in its enrichment of those fields contributes back to evolutionary thought. RNA, on the other hand, is a molecule with a n inordinate number of possible conformations; knowing which to evalua te experimentally is problematic. Analysis of RNA sequences from an ev olutionary perspective reveals patterns of variation and sequence cons traints, and suggests how an RNA sequence is folded up into its higher -order structure.