After giving this some thought, I have concluded that ERV sequences in genomes of organisms are not from viruses but are part of the original design of the organism. I have learned that chimps and humans have many ERVs at the same locations in their genomes. The probability that this could occur by random chance is very, very small. I conclude then that these sequences are not from viruses but are part of the original design of the organism. Also, some of the ERV sequences have been shown to have function.