If you think it's a far-off prospect best left to future generations, think again. Many details still need to be filled in before scientists can build a human from scratch. It is already possible to insert foreign DNA into mice, pigs and sheep. The obstacles to inserting them in humans are mainly technical ones. At this point in human knowledge, it could lead to mutations.
Several techniques are under development to try to avoid that, however.
For the near and midterm future, we're looking at science fiction. As for manipulating intelligence or athletic ability, Frazier says it will take scientists many decades to figure out how to do it. These particular traits don't rely on one gene, but on all genes. To University of Washington professor Phil Bereano, among others, now is the time for all of us to talk with friends and colleagues to hash out the ethical and societal implications of this Brave New World. But there's no shortage of opposition to human engineering.