Viruses helped create the placenta?

[selfAdjoint]

At http://science-matters.blogspot.com/2006/05/endogenous-retroviruses-are-we-product.html , part of a carnival of animacules being celebrated, is an article on endoviruses. These are the descendents of retroviruses that inserted their code into the DNA, which have subsequently settled down as tru host genes.

And not just junk DNA either, as the article asserts that the mammalian placenta, among other structures, is built out of mutated versions of proteins from three separate endovirus genes!

 

[trinitrotoluene]

organelles

yes the same theories have existed for years in the production of organism's organelles. mitochondria and chloroplasts both contain ring DNa that is constistant with such an endo virus, yet exist in every single organism on the planet