From Dan Evans
Mark Buchanan suggests that there might have been a stage between the emergence of a universal genetic code and full-blown Darwinian evolution (23 January, p 34) where genomes capable of heredity and mutation first united in single organisms.
Understanding this “prevolution” is important: it is a process that has not stopped just because evolution proper has started. The horizontal transfer of genetic information between organic organisms happens all the time, including in human beings, where it surely has enormous repercussions.
Given our current ignorance of horizontal gene transfer, we should treat our experiments in this area with great care.
Cardiff, UK
