Placentation and maternal investment in mammals

Capellini, Isabella; Venditti, Chris; Barton, R.A.

Abstract

The mammalian placenta exhibits striking inter-specific morphological variation, yet the implications of such diversity for reproductive strategies and fetal development remain obscure. More invasive hemochorial placentae, in which fetal tissues directly contact the maternal blood supply, are believed to facilitate nutrient transfer, resulting in higher fetal growth rates, and to be a state of relative fetal advantage in the evolution of maternal-offspring conflict. The extent of interdigitation between maternal and fetal tissues has received less attention than invasiveness but is also potentially important because it influences the surface area for exchange. We show that, although increased placental invasiveness and interdigitation are both associated with shorter gestations, interdigitation is the key variable. Gestation times associated with highly interdigitated labyrinthine placentae are 44% of those associated with less interdigitated villous and trabecular placentae. There is however no relationship between placental traits and neonatal body and brain size. Hence, species with more interdigitated placentae produce neonates of similar body and brain size but in less than half the time. We suggest that the effects of placental interdigitation on growth rates and the way that these are traded off against gestation length may be promising avenues for understanding the evolutionary dynamics of conflict.

Citation

Capellini, I., Venditti, C., & Barton, R. (2011). Placentation and maternal investment in mammals. The American Naturalist, 177(1), 86-98. https://doi.org/10.1086/657435

• Journal Article Type: Article
• Publication Date: Jan 1, 2011
• Deposit Date: Oct 4, 2010
• Publicly Available Date: Feb 19, 2014
• Journal: American Naturalist
• Print ISSN: 0003-0147
• Electronic ISSN: 1537-5323
• Publisher: The University of Chicago Press
• Peer Reviewed: Peer Reviewed
• Volume: 177
• Issue: 1
• Pages: 86-98
• DOI: https://doi.org/10.1086/657435
• Keywords: Placenta, Maternal investment, Parent-offspring conflict, Phylogenetic, Foetal growth.
• Public URL: https://durham-repository.worktribe.com/output/1539099