The placenta as a model for understanding the origin and evolution of vertebrate organs

  title={The placenta as a model for understanding the origin and evolution of vertebrate organs},
  author={Oliver W. Griffith and G{\"u}nter P. Wagner},
  journal={Nature Ecology \&Evolution},
How organs originate and evolve is a question fundamental to understanding the evolution of complex multicellular life forms. [] Key Result We argue that a diversity of genomic changes facilitated these physiological transformations and that these changes are likely to have occurred during the evolution of organs more broadly. Finally, we argue that a key aspect to understanding the evolutionary origin of organs is that they are likely to result from novel interactions between distinct cell populations.

Novel tissue interactions support the evolution of placentation

This review demonstrates that placentas are derived from hormonally active organs, that considerable signalling potential exists between maternal and fetal tissues in egg‐laying vertebrates, and that this signalling potential is conserved through the oviparity‐viviparity transition.

The genome of the live-bearing fish Heterandria formosa implicates a role of conserved vertebrate genes in the evolution of placental fish

The results show that a substantial portion of positively selected genes have a function that correlates well with the morphological changes that form the placenta of H. formosa, compared to the corresponding tissue in non-placental poeciliids.

Different Genes are Recruited During Convergent Evolution of Pregnancy and the Placenta

It is concluded that redundancies in gene function have enabled the repeated evolution of viviparity through recruitment of different genes from genomic “toolboxes”, which are uniquely constrained by the ancestries of each lineage.

Recent advances in understanding evolution of the placenta: insights from transcriptomics

This essay examines how studies of gene transcription can inform us about placental evolution in eutherian and marsupial mammals and more broadly about convergent evolution of viviparity and placentation in vertebrates.

Recent advances in understanding evolution of the placenta : insights from transcriptomics

This essay examines how studies of gene transcription can inform us about placental evolution in eutherian and marsupial mammals and more broadly about convergent evolution of viviparity and placentation in vertebrates.

The Primacy of Maternal Innovations to the Evolution of Embryo Implantation.

The emerging scenario suggests that the very initial stages in the evolution of embryo implantation required evolutionary changes to the maternal physiology, which modified an ancestral generic mucosal inflammation in response to the presence of the embryo into an active embedding process.

Uterine cellular changes during mammalian pregnancy and the evolution of placentation

It is concluded that further research is needed to understand the evolution of placentation among viviparous mammals, particularly concerning the level of placental invasiveness, hormonal control, and genetic underpinnings of pregnancy in marsupial taxa.

Tracing the origin of a new organ by inferring the genetic basis of rumen evolution

Comparative analyses reveal that the rumen and the first-chamber stomachs of camels and cetaceans shared a common tissue origin from the esophagus, providing novel insights into the origin and evolution of a complex organ.

Developmental morphology and evolution of extraembryonic membranes of lizards and snakes (Reptilia, Squamata)

Comparisons with viviparous species reveal that both phylogeny and reproductive mode influence variation in extraembryonic membrane development and that phylogenetic variation influences placental evolution.

Embryo implantation evolved from an ancestral inflammatory attachment reaction

The data suggest that implantation in eutherians is derived from an ancestral inflammatory reaction to embryo attachment in the therian ancestor, and the ability to shift from an inflammatory attachment reaction to a noninflammatory period of pregnancy was a key innovation in e Lutherian mammals that allowed an extended period of intimate placentation.



Genomic evolution of the placenta using co-option and duplication and divergence.

Using a timecourse microarray analysis including the entire lifetime of the placenta, molecular and genomic changes that underlie placentation are uncovered and it is found that two distinct evolutionary mechanisms were utilized during placental evolution in mice and human.

Independent Origins and Rapid Evolution of the Placenta in the Fish Genus Poeciliopsis

It is argued that placentas are complex, that they have evolved multiple times in Poeciliopsis, and that there are closely related sister taxa that have either no placentes or intermediate stages in the evolution of a placenta.

Diversification of the eutherian placenta is associated with changes in the pace of life

It is demonstrated that life history differences among eutherian mammals are associated with major transitions in maternofetal interdigitation and placental invasiveness, and that selection for a faster pace of life intensifies parent–offspring conflict.

The genomic and cellular foundations of animal origins.

Comparisons among animals and their unicellular and colonial relatives reveal that the Urmetazoan likely possessed a layer of epithelium-like collar cells, preyed on bacteria, reproduced by sperm and egg, and developed through cell division, cell differentiation, and invagination.

A review of inter- and intraspecific variation in the eutherian placenta

Comparisons within species identify candidate mechanisms that are activated in response to environmental stressors ultimately contributing to the aetiology of obstetric syndromes such as pre-eclampsia.

The evolution of cell types in animals: emerging principles from molecular studies

The recent advent of cell type molecular fingerprinting has yielded initial insights into the evolutionary interrelationships of cell types between remote animal phyla and has allowed us to define some first principles of celltype diversification in animal evolution.

Early animal evolution and the origins of nervous systems

  • G. Budd
  • Biology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2015
It is argued that no simple approach will resolve the first issue, but it remains likely that animals evolved relatively late, and that their nervous systems thus arose during the late Ediacaran, in a context provided by the changing planktonic and benthic environments of the time.

Deep homology and the origins of evolutionary novelty

Advances in developmental genetics, palaeontology and evolutionary developmental biology have recently shed light on the origins of some of the structures that most intrigued Charles Darwin, including animal eyes, tetrapod limbs and giant beetle horns.

Evolution of vertebrate viviparity and specializations for fetal nutrition: A quantitative and qualitative analysis

Phylogenetic analyses indicate that viviparity has originated independently in more than 150 vertebrate lineages, including a minimum of 115 clades of extant squamate reptiles, and substantial matrotrophy has arisen at least 33 times in these v Viviparous clades.