University of Michigan scientists have detected 19 new pieces of viral DNA strands, lurking within human genome after they evaluated DNA information from 2,500 individuals. The latest discovery highlights the impact of certain virus strains and their ability to impact human DNA for generations. The DNA strands were left by viruses that infected human ancestors for the first time, hundreds of thousands of years back.

The scientists behind the genome research project studied 2,500 people and detected that a stretch of newfound DNA, present in 50 of the participants, contained an intact, full genetic recipe for a total virus. The detailed findings of U-M and Tufts University research team have been published in the Proceedings of the National Academy of Sciences.

So far, it isn’t known whether it can replicate, or reproduce. However, other studies of ancient virus DNA have demonstrated that it can have an impact on the humans carrying it.

Besides finding these new strands, scientists have also given confirmation about the presence of 17 other pieces of virus DNA detected in human genomes by other scientific studies conducted in the past.

During the study, researchers inspected the entire span of DNA, or genome, from people worldwide, including a huge number of people from Africa, the place where modern human ancestors had originated prior to their migration across the world. With the help of sophisticated techniques, the team compared main areas of genome of each person to the ‘reference’ human genome.

The researchers at Tufts University and the University of Michigan Medical School worked jointly on the project. The experiment was funded by the National Institutes of Health.

The study findings have come as an add-on to what science is already aware of regarding human endogenous retroviruses, or HERVs. HERVs are infectious viruses that have successfully placed a DNA-based copy of their RNA genetic material within the genomes of our ancestors.