Even though the last common ancestor of Homo sapiens and Neanderthals lived at least 400,000 years ago, traces of our cousins can still be found in our DNA. Fragments of DNA from viruses that affected Neanderthals have been found in modern human genomes according to new research led by Emanuele Marchi from the University of Oxford’s Department of Zoology, which was was published online this month in Current Biology.
Marchi’s results show that humans today have traces of Neanderthal viruses in portions of our DNA that don’t code for protein. DNA from Denisovan bone fragments was compared with genetic samples from Neanderthals and cancer patients today. The results showed that viruses that infected Neanderthals nearly half a million years ago can still be found in our genomes today, and researchers aren’t sure yet what implications that DNA may have for modern diseases like HIV and cancer.
Viral DNA that gets passed down though DNA is known as endogenous retroviruses (ERVs). While ERVs make up almost a tenth of our genomes, it is found in regions that we don’t really understand. There are hints that some of these ERVs can team up to cause disease, but it requires a lot more study. Future research will seek to understand ERVs better to determine if it still has pathogenic properties and if those ancient genetic sequences can possibly be used to target treatments.
As genetic sequencing techniques continue to improve, we will continue to understand our evolutionary history more completely. By learning more about what makes us who we are, we will be able to exploit those processes to improve our quality of life while we’re here and will make it better for those who come after.