ERVs have been used extensively as evidence for evolution, since we share a large number of ERVs with the higher primates and the insertion points are always the same. But as evil as they are, they also play continuous roles in our genome:
If you think that viruses have played no part in human evolution think again. Up to 46 per cent of our DNA was actually provided some time in the past by invading viruses, Ryan says. In comparison, just 1.5 per cent of our genomes arise from the genes we inherit from our primate and animal ancestors.
Ryan argues that Human Endogenous Retroviruses, or Hervs, are a viral integration process integral to the genome of all mammals. It came about by an extensive series of retroviral epidemics that infected our ancestors over tens of millions of years. This means that the virus is something more than just a pest.
Ryan suggests that certain viruses play vital roles in human activity. “There are eight full-length viruses in the human placenta playing different roles, such as a human virus that codes for syncytin 1, which fuses cells together to create a protective layer between mother and baby,” says Ryan. “Proof of the symbiotic inclusion of such viruses as part of our DNA is the fact they have been conserved throughout evolution.”ID has difficulty explaining ERVs because they cause such harm to any given generation and they are clearly detrimental to health in the short term. Here is a reminder of how important ERVs are to evolutionary studies.
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