Today, it is research with human embryonic stem cells and attempts to prepare cloned stem cells for research and medical therapies that are being disavowed as being ethically unacceptable.

Novel technologies and ideas that impinge on human biology and their perceived impact on human values have renewed strains in the relationship between science and society.

That work led to the emergence of the recombinant DNA technology thereby providing a major tool for analyzing mammalian gene structure and function and formed the basis for me receiving the 1980 Nobel Prize in Chemistry.

But I felt it necessary to be part of the war effort and I enlisted in the Navy to be a flyer.

With time, many of the facts I learned were forgotten but I never lost the excitement of discovery.

Moreover, the concern of some that moving DNA among species would breach customary breeding barriers and have profound effects on natural evolutionary processes has substantially disappeared as the science revealed that such exchanges occur in nature.

But the prospects of designing chemical plants for industrial scale chemical processes seemed far less interesting than the chemical events that occur in biological systems.