Environmental effects on reproductive performance in preindustrial women

Abstract

Early life environments can have long-lasting effects on adult reproductive performance, but disentangling the influence of early and adult life environments on fitness is challenging, especially for long-lived species. Using a detailed dataset spanning over two centuries, we studied how early and adult life environments impact reproductive performance in preindustrial women. We assessed the effect of environmental conditions associated with the parish of birth and the parish where the women had their offspring. We considered resource availability differences between rural, urban, northern, and southern parishes by comparing women who switched environments during their lifetime with those who did not. We found that urban-born women had an earlier age at first reproduction and lower offspring survival to adulthood than rural-born women, while South Quebec women had more offspring born than North Quebec women. Moreover, switching from urban to rural led to higher offspring survival, while the reverse had the opposite effect. In addition, moving from South to North resulted in fewer offspring born and surviving, whereas moving from North to South had the inverse effect. Finally, women who changed from rural to urban and from South to North had their first child at an older age compared to those who stayed in the same urbanity type. Our study underscores the complex and interactive effects of early and adult life environments on reproductive traits, highlighting the need to consider both when studying environmental effects on reproductive outcomes.