It changed our world

Sixty years ago a pair of young and then little known scientists made a discovery that would change the world. Cambridge-based James Watson and Francis Crick published a one-page paper in the journal Nature describing their findings about the shape of the genetic material DNA. But with the confirmation of its shape came the revelation of how DNA replicates itself in cell after cell with such accuracy and precision, and so arose the DNA era. No discovery in biological science in the 20th century can match in importance Watson and Crick's findings about the double helix. Some would even argue it trumps Darwin's theory of evolution to make it the single most impactful biological finding of all time. It was fitting that significant Irish connections with the breakthrough were recalled as the anniversary was marked in Dublin with a series of events.

Discoveries flowing from that finding have brought about new ways to make drugs by borrowing DNA from one species and implanting it into bacteria that then become minute drug production factories. It has transformed forensic science with the application of DNA evidence proving near conclusive in criminal cases. Our understanding of DNA as it has grown since that paper published in 1953 has allowed us to provide a complete blueprint of how a human is formed, with each of the three billion steps in our DNA chain revealed and our 20,000 or so genes mapped and identified.

Similar blueprints or genomes have been completed for many other species including mammals, fish, plants, bacteria and viruses, something that gives us tremendous power to identify genes of value in drug discovery, agriculture and food enhancement. Genomes have been completed for all the great apes including gorillas, chimpanzees, bonobos and orang-utans, making it possible to run comparative genetic studies for all the top primates including us. This has revealed we share about 95 per cent of our DNA with the chimpanzee, compelling evidence for the claims made by evolution of distant common ancestors. Yet our ability to peer into the very depths of DNA from any species also delivers extensive lists of common genes conserved by evolution across the widest possible range of species. We share genes with the fruit fly.

For years some argued work on laboratory mice could tell us nothing of value when transposed into humans. Then came genomes which showed we share many biochemical functions with rodents, due to a common ancient ancestor. Watson, Crick and collaborator Maurice Wilkins (courtesy of stunning X-ray diffraction images generated by Rosalind Franklin) shared a Nobel prize for their discovery in 1962. It almost seems too small a reward given the double helix’s subsequent impact on the human condition.