The syncytiotrophoblast is the outermost layer of the placenta, the part that is pressed against the uterus. It’s literally a layer of cells that have fused together, forming a wall. ... There’s no other structure like this anywhere else in the body.”
When evolutionary biologists like Chuong mapped the genomes of these cells, they found that the protein that allowed these cells to fuse into a wall, called syncytin, didn’t look like it came from human DNA. It looked more like HIV.
So the entire premise of the placenta evolving from a virus rests on the fact that the organ has a unique function requiring a unique protein in the body. Saying the source probably is a virus seems quite a leap of thought. And aren't there many highly specialized proteins in the body?
Has anybody has some more information on what protein in a retrovirus looks similar to syncytin?
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So the entire premise of the placenta evolving from a virus rests on the fact that the organ has a unique function requiring a unique protein in the body. Saying the source probably is a virus seems quite a leap of thought. And aren't there many highly specialized proteins in the body?
Has anybody has some more information on what protein in a retrovirus looks similar to syncytin?
Paper that discusses similarities between the envelope glycoprotein of retroviruses and syncytin: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758191/
This field is called paleovirology, and the paper also discusses in some more detail how fragments of viral DNA can end up in human DNA.