In recent times, pregnancy has become an issue of philosophical concern from different perspectives, from bioethical debates on abortion to metaphysical discussions on parthood relations between mothers and embryos, through feminist studies on biomedical practices on pregnancy. Laura Nuño de la Rosa, Mihaela Pavlicev and Arantza Etxeberria, philosophers of biology and evolutionary biologist, engage together to resolve the philosophical puzzle of how to understand the individuality of pregnancy. Their contribution brings about the insight that, from the evo-devo perspective, eutherian pregnant females are historical individuals.

The question of the numerical individuality of pregnant females, whether mother and embryo constitute a single individual, had been previously addressed by the metaphysics of pregnancy. Just like insect colonies, symbiotic organisms, or the Portuguese Man-O-War, pregnancy challenges in its own way the commonsense delineation of biological entities as distinct, self-enclosed, and independent individuals. However, the problem of the individuality of pregnancy has received scarce attention within the philosophical community discussing biological individuality. Physiological as well as evolutionary approaches to individuality tend to assume that two distinct individuals are involved from fertilization to birth and treat pregnant females as containers of their offspring.

The authors first reconstruct classical narratives on the evolution of pregnancy. They identify two main threads that have shaped the container model in evolutionary biology. Firstly, evolutionary accounts on the origin of pregnancy tend to emphasize the continuity between oviparity and viviparity and focus on the embryonic side of this evolutionary transformation. Secondly, evolutionary explanations of pregnancy as an evolutionary strategy have been dominated by the “conflict hypothesis”, which points to the potential for conflicting “interests” between maternal and fetal genes.

In contrast to this view, recent studies in evo-devo have focused on the evolution of relational cooperative novelties in the origination of pregnancy. These evolutionary novelties include the role of inflammation at implantation, as well as the evolution of new uterine cell types that promote codependence and hardly fit into the view of  females as “containers” of their offspring.

In the second part of the paper, the authors argue that this new empirical evidence on the developmental evolution of eutherian reproduction, together with criteria used in evo-devo to individuate historical entities, requires us to reconsider the individuality of pregnancy. In evo-devo, historical units are conceptualised as evolved entities which fulfill two main criteria, their continuous persistence and their non-exchangeability. While the notion of historical individuality has classically been applied to body parts, the authors contend that pregnant females fulfill the criteria to be considered as historical individuals: pregnancy is an evolved relational novelty that gives rise to a new kind of historical individual. Finally, in the last section the authors discuss how the notion of historical individuality differs from, but may also coexist with, other concepts of biological individuality.

Publication:

Nuño de la Rosa L, Pavlicev M and Etxeberria A (2021) Pregnant Females as Historical Individuals: An Insight From the Philosophy of Evo-Devo. Front. Psychol. 11:572106. doi: 10.3389/fpsyg.2020.572106