Misconceptions about Conception and Other Fallacies: Historical Bias in Reproductive Biology

Natural selection (differential reproduction) is a major tenet of evolutionary theory. In mammals the success of reproduction is primarily controlled by females who provide the majority of offspring care via gestation and lactation. In some species, maternal care also extends post-weaning. This primacy of female reproduction in evolution has not quite crept into our understanding of organismal adaptations in anatomy, physiology, and behavior. This cultural legacy has left its mark and led to misconceptions in our understanding of reproductive biology that are especially prominent in the understanding of reproduction in the general public. Here, I give examples of such misconceptions. I focus on aspects of physiology (the "sperm race," the "estrous cycle," the "28-day" menstrual cycle, "sex" hormones, and meiosis) as well as aspects of terminology in morphology and behavior. The issues I raise are not new, but all remain embedded in the teaching of reproductive biology especially at the introductory level. For each issue, I examine the historical bias, the consequences of that bias, and, more importantly, ways to ameliorate that bias going forward.