Agustin Fuentes: DNA Is Not a Blueprint: How Genes Really Work
Sequencing of a fetal genome from parental samples demonstrates how we have advanced in genetic analyses, but the title of a June 6 article in The New York Times , "DNA Blueprint for Fetus Built Using Tests of Parents," gives me pause. While the content does reflect a few interviews where researchers caution against overemphasizing what DNA sequences can tell us, the majority of the public reading the headline will see, yet again, an oversimplified and potentially damaging version of what we actually know about genetics.
Genes play an important role in our development and functioning, not as directors but as parts of a complex system. "Blueprints" is a poor way to describe genes. It is misleading to talk about genes as doing things by themselves. There are very few instances of direct gene-to-trait scenarios, even in well known "genetic" disorders. Traits emerge from the interactions of genes and a range of developmental and environmental influences, and similar DNA sequences often produce slightly different outcomes. Our DNA influences who we are, but not in a linear or easily described manner. (See here for more.)
DNA contains basic information that, when combined with the appropriate organic structures (in the egg) and context (the mother's uterus), will facilitate the growth of a single cell (the combined sperm and egg) into a multibillion-cell person. Note that I say "facilitate," not "determine." The DNA is not the blueprint of life; rather, it contains many of the basic codes and signals for the development of an organism. At its core DNA contains the basic information needed to assemble molecules called "proteins," which are the building blocks of our bodies, and it also acts to regulate how and where different proteins are made and used...