"You can conceive of life where homochirality is not so widespread," said Sandra Pizzarello, an Arizona State University biochemist who was not involved in the study.
Group membership is of elementary importance to our wellbeing and because humans are very sensitive to signals of exclusion, a silence is generally taken as a sign of rejection.
Its successor, on the other hand, appeared to pit key socioeconomic groups in a life-or-death struggle and was widely seen by contemporary observers as marking a historical departure.
A wise herd will learn to tolerate the eccentricity of those who rise above the average, and to treat with a minimum of ferocity those who fall below it.
A far bigger cause of concern than the growth of national groups, however, is the increasing number of migrants who return to their countries of origin.