Humanity has long dreamed of perfection, striving to be faster, stronger and brighter, pushing nature to the limit. With the birth of Louise Brown in 1978, the test tube finally succeeded where the pumpkin had failed, and the year she turned 11, scientists moved beyond making life in a lab: They found a way to peer into an embryo's genes and predict what that life might be like.
That ability is now morphing into a whole new approach to baby-making, one that gives people an unprecedented power to preview, and pick, the genetic traits of their prospective children.
Just as Paracelsus wrote that his recipe worked best if done in secret, modern science is quietly handing humanity something the quirky Renaissance scholar could only imagine: the capacity to harness our own evolution. We now have the potential to banish the genes that kill us, that make us susceptible to cancer, heart disease, depression, addictions and obesity, and to select those that may make us healthier, stronger, more intelligent. The question is, should we?
Recent breakthroughs have made it possible to scan every chromosome in a single embryonic cell, to test for genes involved in hundreds of “conditions,” some of which are clearly life-threatening while others are less dramatic and less certain – unlikely to strike until adulthood if they strike at all.
And science is far from finished. On the horizon are DNA microchips able to analyze more than a thousand traits at once, those linked not just to a child's health but to enhancements – genes that influence height, intelligence, hair, skin and eye colour and athletic ability.
Such tests were devised to help those suffering from infertility. But people well able to have babies the old-fashioned way now opt for IVF and embryo screening, paying a steep premium in return for the chance to have greater genetic control over their offspring.
