“Some twenty-five years ago Joneses were everywhere among us and not, as now, withdrawn to South Continent and organized into a ruthless aggressor nation. They made up about thirty per cent of the population and had become a closely knit organization devoted to mutual help. They held the balance of political power in every election from the municipal to the planetary level and virtually monopolized production and finance. There were fanatics and rabble-rousers among them who readily exploited a rising tide of discontent over a series of curbing laws, finally pushed through by a planetary majority, united at last in self-defense against the rapacity and ruthless self-interest of the Joneses. “The Joneses withdrew en masse to South Continent. Some sincerely wished them well; others scoffed at the secession as a sulky and childish gesture. Only a handful of citizens guessed the terrible truth, and were laughed at for their pains. Five years after their withdrawal the Joneses returned across the Vandemeer Peninsula and the war had begun. “A final word. There has been much loose talk among the troops about the slogan of the Joneses, which goes L_{T}=L_{O}e-^{T/2N}. Some uninformed people actually believe it is an invocation which gives the Joneses supernatural power and invulnerability. It is not. It is merely an ancient and well-known formula in genetics which quantitatively describes the loss of unfixed genes from a population. By mouthing this formula, the Joneses are simply expressing in a compact way their ruthless determination that all genes except theirs shall disappear from the planet and the Joneses alone survive. In the formula L_{T} means the number of genes after the lapse of T years, L_{O} means the original number of genes, e means the base of the natural system of logarithms and N means number of generations.” The surgeon said slowly and with wonder: “So _that_ was my God!” He stretched out his hands before him. The fingers were rock-steady. Ross left him and paced the corridor uneasily. Fine. Now he knew. Lost genes in genetically small populations. On Halsey’s Planet, some fertility gene, no doubt. On Azor, a male-sex-linked gene that provides men with the backbone required to come out ahead in the incessant war of the genders? Bernie was a gutless character. Here, all too many genes determining somatotype. On the planets that had dropped out of communication, who knew? Scientific-thought genes? Sex-drive-determining genes? One thing was clear: any gene-loss was bad for the survival of a planetary colony. Evolution had——on Earth——worked out in a billion trial-and-error years a working mechanism, man. Man exhibited a vast range of variation, which was why he survived almost any conceivable catastrophe. Reduce man to a single type and he is certain to succumb, sooner or later, to the inevitable disaster that his one type cannot cope with.