Darwin's Doubt: The Explosive Origin of Animal Life and the Case for Intelligent Design

by Stephen C. Meyer

Biologists know of an additional source of epigenetic information stored in the arrangement of sugar molecules on the exterior surface of the cell membrane. Sugars can be attached to the lipid molecules that make up the membrane itself (in which case they are called “glycolipids”), or they can be attached to the proteins embedded in the membrane (in which case they are called “glycoproteins”). Since simple sugars can be combined in many more ways than amino acids, which make up proteins, the resulting cell surface patterns can be enormously complex. As biologist Ronald Schnaar explains, “Each [sugar] building block can assume several different positions. It is as if an A could serve as four different letters, depending on whether it was standing upright, turned upside down, or laid on either of its sides. In fact, seven simple sugars can be rearranged to form hundreds of thousands of unique words, most of which have no more than five letters.”24 These sequence-specific information-rich structures influence the arrangement of different cell types during embryological development. Thus, some cell biologists now refer to the arrangements of sugar molecules as the “sugar code” and compare these sequences to the digitally encoded information stored in DNA.25 As biochemist Hans-Joachim Gabius notes, sugars provide a system with “high-density coding” that is “essential to allow cells to communicate efficiently and swiftly through complex surface interactions.”26 According to Gabi...