Scientists from Tufts University in Massachusetts explain in a press release how relics of ancient pandemics in the form of viral DNA sequences embedded in our genomes are still active in healthy people today.
These ancient retroviruses (viruses that use RNA as their genomic material) comprise around 8 percent of the human genome, left behind as a result of infections from millions of years ago.
Normally, viral genetic material is not passed down from generation to generation. But some ancient retroviruses have gained the ability to infect germ cells and thus pass their DNA down to future generations.
Publishing their results in PLOS Biology, the researchers reveal a level of retroviral activity in the human body that was previously unknown.
'There is still much to learn about the ancient viruses that linger in the human genome, including whether their presence is beneficial and what mechanism drives their activity' said lead author Aidan Burn. 'Answering these questions could reveal previously unknown functions for these ancient viral genes and better help researchers understand how the human body reacts to evolution alongside these vestiges of ancient pandemics.