Analogies for Understanding and Problems for Speculating on How DNA Creates 3-Dimensional Structures
Interesting quick-read from Quanta magazine on how we’re all essentially comprised of basic ‘instruction’ sets known as DNA:
One of the miracles of nature is embryogenesis: the transformation of a single fertilized egg cell into an embryo that will eventually become a fully formed baby animal. Various analogies have been applied to this process, from the primitive concept of a blueprint to Richard Dawkins’ cake recipe that calls for genetic ingredients. To my mind, the best analogy comes from Gary Marcus’ 2004 book The Birth of the Mind: How a Tiny Number of Genes Creates the Complexities of Human Thought. According to Marcus, embryogenesis most resembles a genetic computer program that produces a three-dimensional living organism. Marcus states that every gene is like a single line of code. All the genes together form the master DNA program, which is copied and run simultaneously in trillions of cells to achieve this miracle of physicochemical engineering.
Our first problem explores the kind of issues that need to be solved by DNA programming to create 3-D structures. Note that this example is not based on an actual biological case but is meant to illustrate the general principles of how chemical gradients can be used by the embryo in conjunction with constraints in properties of available molecules.