Virus DNA in human genome (evolution by infection)

If it wasn’t for virus DNA in human genome, humans would NOT exist. The evolution of the mammalian placenta has happened because of endogenous retroviruses. The viruses in human genome have come from infections millions of years ago that have stayed around in our DNA. The human endogenous retroviruses are on longer functional viruses capable of infecting. Instead, what’s left in the human genome are parts of these viruses, specific important genes. These are the critical genes for placental evolution. Placental mammals have adopted these genes in a wonderful way, and turned a tool used by viruses to infect cells into a tool for creating the placenta. The evolution of the mammalian placenta is not a rare, one time event. Instead, the evolution of the mammalian placenta has occurred over and over. What’s even more astounding is that the placenta has evolved in non-mammalian species as well. We humans need retrovirus genes for our development. We descend from viruses. Subscribe: