Why do placentas evolve? Evidence for a morphological advantage during pregnancy in live-bearing fish.

ABSTRACT: A live-bearing reproductive strategy can induce large morphological changes in the mother during pregnancy. The evolution of the placenta in swimming animals involves a shift in the timing of maternal provisioning from pre-fertilization (females supply their eggs with sufficient yolk reserves prior to fertilization) to post-fertilization (females provide all nutrients via a placenta during the pregnancy). It has been hypothesised that this shift, associated with the evolution of the placenta, should confer a morphological advantage to the females leading to a more slender body shape during the early stages of pregnancy. We tested this hypothesis by quantifying three-dimensional shape and volume changes during pregnancy and in full-grown virgin controls of two species within the live-bearin

SUBMITTER: Fleuren M 

PROVIDER: S-EPMC5901924 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature