focuses on what she perceives as the pseudoscientific speculations and irrational, fear-of-death-driven fantasies of these thinkers, their disregard for laymen and the remoteness of their eschatological visions. Another critique is aimed mainly at "algeny" (a portmanteau of alchemy and genetics), which Jeremy Rifkin defined as "the upgrading of existing organisms and the design of wholly new ones with the intent of 'perfecting' their performance". It emphasizes the issue of biocomplexity and the unpredictability of attempts to guide the development of products of biological evolution. This argument, elaborated in particular by the biologist Stuart Newman, is based on the recognition that cloning and germline genetic engineering of animals are error-prone and inherently disruptive of embryonic development. Accordingly, so it is argued, it would create unacceptable risks to use such methods on human embryos. Performing experiments, particularly ones with permanent biological consequences, on developing humans would thus be in violation of accepted principles governing research on human subjects (see the 1964 Declaration of Helsinki). Moreover, because improvements in experimental outcomes in one species are not automatically transferable to a new species without further experimentation, it is claimed that there is no ethical route to genetic manipulation of humans at early developmental stages. As a practical matter, however, international protocols on human subject research may not present a legal obstacle to attempts by transhumanists and others to improve their offspring by germinal choice technology. According to legal scholar Kirsten Rabe Smolensky, existing laws would protect parents who choose to enhance their child's genome from future liability arising from adverse outcomes of the procedure. 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