Metabolic Pathways Produce Evolutionary Roadblock
by Brian Thomas, M.S. *
Researchers at Northwestern University have discovered what they believe to be evidence for the evolution of strong and healthy metabolic networks within cells. What they may have actually found, however, is yet more confirmation that living organisms were skillfully created.
A university news release stated that the findings demonstrate “that evolution has produced cell metabolisms that are especially well suited to handle potentially harmful changes like gene deletions and mutations.”1 In their study published in Proceedings of the National Academy of Sciences, the researchers report, “[W]e find that the metabolic networks considered are exceptionally robust and that this robustness is not due to the structure…but rather arises from the organization of…metabolites.”2 This means that a healthy metabolism reflects specified order, not randomness.
Cell metabolism involves a large network of chemical reactions that are responsible for converting nutrients into usable products and energy. It is like a highly complex information roadway system over which chemicals travel to reach their cellular destinations.
What the Northwestern University team discovered was that the cellular roadway system was not only highly complex, but exceptionally well-organized to handle “gene deletions and mutations,” able to automatically re-route information without disrupting flow. The investigators found that “the likelihood of large failure cascades in a metabolic network is unusually small, compared to what they would expect from comparable, randomly structured networks.”1 The bacterial metabolism that was studied showed the potential to circumvent roadblocks. If metabolic “Route A” is impeded by a malfunctioning protein, then “Route B” is already in place.
While the chemical engineers who contributed to this study should be applauded for the quality of their laboratory work, their conclusion that evolution produced this remarkable metabolic structure is off base. The amazing built-in re-routing processes, though not needed for short-term survival, are necessary for bacteria to proliferate and perform their biological or ecological functions over thousands of years, millions of generations, and countless mutations. Without this alternate routing scheme for chemical reactions to follow, metabolic roadblocks would have caused cell death long ago. Dead cells can’t evolve. The fact that these cells are still around and still robust is a strong indication that they were purposefully set up for success.
Natural processes are not smart enough or powerful enough to devise such a complex, interactive system, but a Creator God is. Moreover, His provision of other backup systems throughout the world—from redundancy in the genetic code and certain body organ functions to differing creatures’ abilities to maintain atmospheric gas balance—clearly demonstrates His wisdom and grace. In the case of metabolic pathways, the most appropriate conclusion is that the Organizer was exceptionally wise to have programmed plans B and C so that living things can survive in a hostile world.
- New evidence on the robustness of metabolic networks. Northwestern University press release, September 4, 2008.
- Smart, A. G., L. A. N. Amaral, and J. M. Ottino. 2008. Cascading failure and robustness in metabolic networks. Proceedings of the National Academy of Sciences. 105 (36): 13227.
* Mr. Thomas is Science Writer.
Article posted on September 15, 2008.