Actually, this research demonstrates this, answers your question, and described in the following.
From:
ERVs
Three Layers of Endogenous Retroviral Evidence for the Evolutionary Model
"The targets of retroviruses are usually somatic cells, but if the infected cell happens to be a sperm or egg cell, known as a gamete, or a testicular or ovarian cell that divides into a gamete, that gamete may be used to produce an offspring. In such a case, the provirus becomes a permanent fixture within the offspring’s genome. Its permanence is due to fact that “there is no mechanism for removing proviruses precisely from the genome, without leaving behind a solo LTR or deleting chromosomal DNA (
Johnson and Coffin, 1999).” Although the retrovirus was foreign to the organism it infected, and thus would be considered exogenous to that organism, once passed on to the organisms offspring, it would be present in the offspring’s natural, healthy state, and thus would considered endogenous to it.
Now being passed on from one generation to the next, ERVs accumulate copying mistakes by DNA polymerase during subsequent host cell replication. Since ERVs are generally not conserved, they accumulate mutations at the same rate as introns. And, as with introns, over time, the mutations can become fixed in the host population’s gene pool (
Boeke and Stoye, 1997. In Coffin, Hughes, & Varmus, 1997). Given enough time, enough mutations accumulate to render the ERV incapable of activation.
If two or more individuals have ERVs of the same family at the same loci, one might think that there exist two plausible explanations: 1) that a retrovirus inserted in a common ancestor, and was passed on to the individuals via sexual reproduction; or 2) that separate retroviruses inserted in the same loci in separate ancestors, and were passed on to the individuals from each respective ancestor. What rules out the latter of these explanations for the majority of shared ERVs is the highly random nature of integration discussed earlier, and shared mutation among ERVs in identical loci, to be discussed shortly.
Thus, we can then conclude—regardless of how many individuals have retroviruses in the same loci of their genomes—the majority of those retrovirus necessarily inserted within the genomes individual cells of individual ancestral organisms common to each of them, and were passed on to those individuals via sexual reproduction. If the organisms are of the same species the individual from which the insertion originated may likely have also been of the same species. If, however, the organisms are of different species, the shared ERVs are referred to as orthologous, and that is when things get interesting."
