Many great things can be accomplished through genetic engineering, but scientific progress is being halted by the opposition 's use of arguments with questionable logic. Most notably is their fear of designer babies. The problem with designer babies is that complex beneficial traits such as height, strength, intelligence, and attractiveness aren’t determined by one gene, and are also dependent on many other variables that aren’t genetic. Some traits such as the shape of an earlobe, eye color, or an individual’s susceptibility to certain diseases are determined by a single gene, and that specific gene can be identified and isolated by scientists. Professor of translational epidemiology at Emory University, Cecile Janssens states, “Even when all genes and their complex interactions are completely understood, our ability to use gene editing for favorable traits will remain limited because human traits are just not genetic enough.” (Janssens). This would mean that giving an unfair advantage to a so called designer baby would be impossible, because we are unable know if these traits are entirely genetic, let alone isolate and edit them. Another hole in the opposition 's logic is the idea of a fetus needing consent to be genetically modified on. If it’s amoral for a fetus to undergo a process such as genetic modification in order to make it healthy, then it must also be wrong to give baby medicine, vaccines, or surgery. The opposition also commonly thinks that genetic