Transhumanists and other supporters of human genetic engineering do not dismiss practical concerns out of hand, insofar as there is a high degree of uncertainty about the timelines and likely outcomes of genetic modification experiments in humans. However, bioethicist James Hughes suggests that one possible ethical route to the genetic manipulation of humans at early developmental stages is the building of computer models of the human genome, the proteins it specifies and the tissue engineering he argues that it also codes for. With the exponential progress in bioinformatics, Hughes believes that a virtual model of genetic expression in the human body will not be far behind and that it will soon be possible to accelerate approval of genetic modifications by simulating their effects on virtual humans. Public health professor Gregory Stock points to artificial chromosomes as an alleged safer alternative to existing genetic engineering techniques.
