There's evidence that a gene responsible for placental development in humans came from an ancient virus!
Syncytin-1, a protein coded by the ERV1 gene which is crucial for placental development. Syncytin-1 is a human endogenous retroviral element, viral genetic material that has incorportated into our genome. It is conserved among apes and old-world monkeys.
Syncytin-2, another placental development gene, is derived from a different retrovirus.
spacemonkeymafia42 t1_j9nfn1v wrote
Reply to comment by fil- in How did the placenta evolve? by fil-
There's evidence that a gene responsible for placental development in humans came from an ancient virus!
Syncytin-1, a protein coded by the ERV1 gene which is crucial for placental development. Syncytin-1 is a human endogenous retroviral element, viral genetic material that has incorportated into our genome. It is conserved among apes and old-world monkeys.
Syncytin-2, another placental development gene, is derived from a different retrovirus.