High schools throughout the United States, especially those serving high poverty and high minority communities, struggle to find qualified science teachers to fill vacancies, a situation that has been further exacerbated by the COVID-19 pandemic. This science teacher shortage is caused by a combination of low levels of recruitment into the profession and high levels of attrition from the profession, which has led those hoping to ameliorate the shortage to focus on either increasing the recruitment of pre-service teachers into science teacher preparation programs or improving the retention of in-service science teachers in the field. Instead of viewing these two ends of the so-called science teacher pipeline as distinct and dichotomous, the primary goal of this two-paper dissertation is to explore and characterize the connection between the recruitment and retention of science teachers. In the first paper, a content analysis approach is used to identify the factors that motivated six science undergraduates to apply to a secondary science teacher preparation program and compare their motivations to those described in the literature. In the second paper, a multi-case study is conducted to determine how the science teaching commitments of six pre-service science teachers changed over the course of their science teacher preparation program and to identify the elements of their science teacher preparation program that contributed to changing commitments to science teaching. By drawing upon the findings of both papers, this dissertation argues that there is a link between science teacher recruitment and retention, and it lies in the conversion of interest in science teaching into commitment to science teaching. This connection positions science teacher preparation programs not only as instruments of science teacher recruitment, but also as a first line of defense against science teacher attrition.