Phylogenetic Evidence for Early Hemochorial Placentation in Eutheria

TitlePhylogenetic Evidence for Early Hemochorial Placentation in Eutheria
Publication TypeJournal Article
Year of Publication2009
AuthorsELLIOT MG, CRESPI BJ
JournalPlacenta
Volume30
Issue11
Pagination949 - 967
Date Published11/2009
AbstractThe eutherian placenta is remarkable for its structural and functional variability. In order to construct and test comparative hypotheses relating ecological, behavioral and physiological traits to placental characteristics it is first necessary to reconstruct the historical course of placental evolution. Previous attempts to do so have yielded inconsistent results, particularly with respect to the early evolution of structural relationships between fetal and maternal circulatory systems. Here, we bring a battery of phylogenetic methods – including parsimony, likelihood and Bayesian approaches – to bear on the question of placental evolution. All of these approaches are consistent in indicating that highly invasive hemochorial placentation, as found in human beings and numerous other taxa, was an early evolutionary innovation present in the most ancient ancestors of the living placental mammals.
DOI10.1016/j.placenta.2009.08.004
DOI10.1016/j.placenta.2009.08.004