Genetics of reproduction and its evolutionary significance

PROBLEM: To provide an evolutionary perspective on reproductive problems. METHOD OF STUDY: A broad range of evolutionary and reproductive data in the literature were analyzed. RESULTS: Evolutionary considerations provide some insight into two aspects of human reproduction. First, the inefficiency of the reproductive process (20-35% of fertilized ova yield successful pregnancies) may reflect the stress placed on the reproductive process by the relatively short evolutionary time between the hunter-gatherer and settled agricultural patterns of human life. Second, the immaturity of the immune response of the human newborn is most likely a consequence of its delivery while still in the embryonic/fetal stage of development. Delivery at this time is necessitated by the rapid development of the human brain in utero. CONCLUSIONS: The attempts to develop reproductive technologies should take into account the fundamental limits on the human reproductive process. A variety of in utero preventive and therapeutic techniques should be developed to provide the newborn with enhanced resistance to infectious diseases or to correct congenital defects. All new procedures should be thoroughly investigated and proved before being put into clinical practice.