excerpts from the book Earth Abides (1949) by George R. Stewart:
"It has never happened!" cannot be construed to mean, "It can never happen!" -- as well say, "Because I have never broken my leg, my leg is unbreakable," or "Because I've never died, I am immortal." One thinks first of some great plague of insects -- locusts or grasshoppers -- when the species suddenly increases out of all proportion, and then just as dramatically sinks to a tiny fraction of what it has recently been. The higher animals also fluctuate. The lemmings work upon their cycle. The snowshoe-rabbits build up through a period of years until they reach a climax when they seem to be everywhere; then with dramatic suddenness their pestilence falls upon them. Some zoologists have even suggested a biological law: that the number of individuals in a species never remains constant, but always rises and falls -- the higher the animal and the slower its breeding-rate, the longer its period of fluctuation.
During most of the nineteenth century the African buffalo was a common creature on the veldt. It was a powerful beast with few natural enemies, and if its census could have been taken by decades, it would have proved to be increasing steadily. Then toward the century's end it reached its climax, and was suddenly struck by a plague of rinderpest. Afterwards the buffalo was almost a curiosity, extinct in many parts of its range. In the last fifty years it has again slowly built up its numbers.
As for man, there is little reason to think that he can in the long run escape the fate of other creatures, and if there is a biological law of flux and reflux, his situation is now a highly perilous one. During ten thousand years his numbers have been on the upgrade in spite of wars, pestilences, and famines. This increase in population has become more and more rapid. Biologically, man has for too long a time been rolling an uninterrupted run of sevens.
Consider the case of Captain Maclear's rat. This interesting rodent inhabited Christmas Island, a small bit of tropical verdure some two hundred miles south of Java. The species was first described for science in 1887, the skull being noted as large and strongly built, with beaded supra-orbital edges and the anterior edge of the zygomatic plate projecting forward conspicuously.
A naturalist observed the rats as populating the island "in swarms," feeding upon fruit and young shoots. To the rats the island was as a whole world, an earthly paradise. The observer noted: "They seem to breed all the year round." Yet such was the luxuriance of the tropical growth that the rats had not attained such numbers as to provide competition among members of the species. The individual rats were extremely well nourished, and even unduly fat.
In 1903 some new disease sprang up. Because of their crowding, and also probably because of the softened condition of the individuals, the rats proved universally susceptible, and soon were dying by thousands. In spite of great numbers, in spite of an abundant supply of food, in spite of a very rapid breeding rate, the species is extinct.
"It has never happened!" cannot be construed to mean, "It can never happen!" -- as well say, "Because I have never broken my leg, my leg is unbreakable," or "Because I've never died, I am immortal." One thinks first of some great plague of insects -- locusts or grasshoppers -- when the species suddenly increases out of all proportion, and then just as dramatically sinks to a tiny fraction of what it has recently been. The higher animals also fluctuate. The lemmings work upon their cycle. The snowshoe-rabbits build up through a period of years until they reach a climax when they seem to be everywhere; then with dramatic suddenness their pestilence falls upon them. Some zoologists have even suggested a biological law: that the number of individuals in a species never remains constant, but always rises and falls -- the higher the animal and the slower its breeding-rate, the longer its period of fluctuation.
During most of the nineteenth century the African buffalo was a common creature on the veldt. It was a powerful beast with few natural enemies, and if its census could have been taken by decades, it would have proved to be increasing steadily. Then toward the century's end it reached its climax, and was suddenly struck by a plague of rinderpest. Afterwards the buffalo was almost a curiosity, extinct in many parts of its range. In the last fifty years it has again slowly built up its numbers.
As for man, there is little reason to think that he can in the long run escape the fate of other creatures, and if there is a biological law of flux and reflux, his situation is now a highly perilous one. During ten thousand years his numbers have been on the upgrade in spite of wars, pestilences, and famines. This increase in population has become more and more rapid. Biologically, man has for too long a time been rolling an uninterrupted run of sevens.
Consider the case of Captain Maclear's rat. This interesting rodent inhabited Christmas Island, a small bit of tropical verdure some two hundred miles south of Java. The species was first described for science in 1887, the skull being noted as large and strongly built, with beaded supra-orbital edges and the anterior edge of the zygomatic plate projecting forward conspicuously.
A naturalist observed the rats as populating the island "in swarms," feeding upon fruit and young shoots. To the rats the island was as a whole world, an earthly paradise. The observer noted: "They seem to breed all the year round." Yet such was the luxuriance of the tropical growth that the rats had not attained such numbers as to provide competition among members of the species. The individual rats were extremely well nourished, and even unduly fat.
In 1903 some new disease sprang up. Because of their crowding, and also probably because of the softened condition of the individuals, the rats proved universally susceptible, and soon were dying by thousands. In spite of great numbers, in spite of an abundant supply of food, in spite of a very rapid breeding rate, the species is extinct.
