PRESIDENTIAL ADDRESS: IS THE SANCTITY OF LIFE ETHIC TERMINALLY ILL?

Our growing technical capacity to keep human beings alive has brought the sanctity of life ethic to the point of collapse. The shift to a concept of brain death was already an implicit abandonment of the traditional ethic, though this has only recently become apparent. The 1993 decision of the British House of Lords in the case of Anthony Bland is an even more decisive shift towards an ethic that does not ask or seek to preserve human life as such, but only a life that is worth living. Once this shift has been completed and assimilated, we will no longer need the concept of brain death. Instead we can face directly the real ethical issue: when may doctors intentionally end the life of a patient?     

IS EXTRATERRESTRIAL ORGANIC MATTER RELEVANT TO THE ORIGIN OF LIFE ON EARTH?

I review the relative importance of internal and external sources of prebiotic molecules on Earth at the time of life's origin 3.7Gyr ago. The efficiency ofsynthesis in the Earth's atmosphere was critically dependent on its oxidation state. If the early atmosphere was non-reducing and CO2-dominated, external delivery might havebeen the dominant source. Interplanetary dust grains and micrometeorites currently deliver carbonaceous matter to the Earth's surface at a rate of 3 × 10⁵kg/yr(equivalent to a biomass in 2Gyr), but this may havebeen as high as 5 × 10⁷kg/yr (a biomass in only10Myr) during the epoch of late bombardment. Much ofthe incoming material is in the form of chemically inactive kerogens and amorphous carbon; but if the Earth once had a dense (10-bar) atmosphere, small comets rich in avariety of prebiotic molecules may have been sufficiently air-braked to land non-destructively. Lingering uncertainties regarding the impact history of the Earth and the density and composition of its early atmosphere limit our ability to draw firm conclusions.     

IS IT NEUROSIS?

So-called “minor psychiatry,” the treatment of neurosis in persons who are not psychotic, may well be undertaken by the general practitioner.The first duty of the physician in dealing with a neurotic person is to determine whether psychosis may develop. He must be patient and thorough in hearing the history of the case and should have full information on the patient''s life and family.A recent classification of the neuroses is given and the more generally recognized symptoms of these conditions are described.     

IS LIFE IMPOSSIBLE? INFORMATION,SEX, AND THE ORIGIN OF COMPLEX ORGANISMS

The earliest organisms are thought to have had high mutation rates. It has been asserted that these high mutation rates would have severely limited the information content of early genomes. This has led to a well‐known “paradox” because, in contemporary organisms, the mechanisms that suppress mutations are quite complex and a substantial amount of information is required to construct these mechanisms. The paradox arises because it is not clear how efficient error‐suppressing mechanisms could have evolved, and thus allowed the evolution of complex organisms, at a time when mutation rates were too high to permit the maintenance of very substantial amounts of information within genomes. Here, we use concepts from the formal theory of information to calculate the amount of genomic information that can be maintained. We identify conditions under which much higher levels of genomic information can be maintained than previously considered possible among origin‐of‐life researchers. In particular, we find that the highest levels of information are maintained when many genotypes produce identical phenotypes, and when reproduction occasionally involves recombination between multiple parental genomes. There is a good reason to believe that these conditions are relevant for very early organisms, and thus the results presented may provide a solution to a long‐standing logical problem associated with the early evolution of life.