 Since humans stopped reproducing among themselves, what has been the greatest impact on human biology?
[Transcriber's Note: This etext was produced from Worlds of If Science Fiction, August 1957. ] I was wandering among the tall grass of the slopes, listening to the soft whistling of the wind; allowing the grass to caress my toga and thighs. And Man returned, and settled down to live. Everything has evaporated in Maternite. They were aware that they stood in the midst of an unprecedented happening; indeed, an emergency. They were created so long ago, indeed, that the ignorant believe them to have been constructed by the gods themselves. Prayers and supplications were offered to the gods, priests were sent to sacrifice, and finally, as the light of the sun was falling between the pillars, the High Priest of the Maternite Machine was heard. By this time, unfortunately, many of the Conclave had departed for home and supper. Yet perhaps it is for the best, for those left were the most earnest and intelligent. Know, then, that once granted a few cells of Prelife, it is an easy matter for the Maternite Machine to add more and more; thus assuring us, as has always been, a continuous source of Prelife to be born by the Generating Machine as children. The machines bear the exact number of children each year to balance the number of us whom the gods claim. "But now," he continued, however, with less assurance and indeed with even a stutter here and there, "an unprecedented situation has arisen. They quieted, breathing heavily, and I asked, "Is there no way, then, to produce more Prelife in order that the machines may produce more children for us? "As I have said," he replied, "give the machines but a bit of Prelife and they will produce more. Rocsates leaned forward and asked, "Must there not—must there not have been a beginning to Prelife? "Must there not, long ago, have been a source of Prelife: a source now forgotten? "I know well the legend of the animals, but what does it have to do—" The heads of the Conclave were turning to me, quizzically. "It is said that many thousands of years ago, time without reckoning, there existed on the earth creatures who were alive like us, and yet not like us. Rocsates' voice made itself heard. It is recorded most scientifically in the films." "May it not be," Rocsates put in, "that these animals had no machines to reproduce their kind?
 significant reduction of the appearance and function of sex organs
 significant reduction of the appearance and function of sex organs  more predictable measures for increasing the global population  gradual decrease in the overall intellectual quotient of a society  a lower prevalence of birth defects and learning disabilities