Placentation and maternal investment in mammals

Barton, Robert�A.; Capellini, Isabella; Venditti, Chris; Barton, Robert A.

Abstract

The mammalian placenta exhibits striking interspecific morphological variation, yet the implications of such diversity for reproductive strategies and fetal development remain obscure. More invasive hemochorial placentas, 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 placentas are 44% of those associated with less interdigitated villous and trabecular placentas. There is, however, no relationship between placental traits and neonatal body and brain size. Hence, species with more interdigitated placentas 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 parent‐offspring conflict.

Citation

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

• Journal Article Type: Article
• Acceptance Date: Sep 8, 2010
• Online Publication Date: Nov 18, 2010
• Publication Date: Jan 1, 2011
• Deposit Date: Mar 20, 2015
• Publicly Available Date: Mar 20, 2015
• Journal: The American naturalist
• Print ISSN: 0003-0147
• 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, Parent‐offspring conflict, Life history, Brain evolution, Reproductive strategies, Gestation.
• Public URL: https://hull-repository.worktribe.com/output/371860
• Publisher URL: http://www.jstor.org/stable/10.1086/657435
• Additional Information: Copy of article first published in The American naturalist, 2011, v.177, issue 1
• Contract Date: Mar 20, 2015