Structural evolution of glycans in algae

Abstract

The compositions and structures of the principal glycans in the eleven recognised algal phyla are reviewed and correlated with the positions of the phyla in a phylogenetic tree proposed by Chapman. By appealing to fossil evidence for the conservative nature of many algal species, tentative inferences are made concerning the probable order of evolution of the glycans. In general, the evolution of morphological complexity has been accompanied by the replacement of irregular glycan structures by more regular ones, containing a smaller number of different sugar residues. There are, however, some notable “missing links” and apparent exceptions among glycans that participate in calcification and silicification processes. © 1983 IUPAC