I’ve discussed the ERV evidence here and elsewhere, so I thought I would add some information that has helped me discuss the topic in the past. I will probably break this up into several posts to make it a bit more manageable.
First, the human and chimp genome papers have the best info for the overall tally of ERV’s in each genome.
From the 2001 human genome paper:
https://www.nature.com/articles/35057062/tables/11
From the 2005 chimp genome paper:
https://www.nature.com/articles/nature04072/tables/2
For the human genome, there foiund ~203,000 ERV’s (ERV classes I-III) that take up about 5% of the human genome. MaLR’s are viral LTR’s that have become part of transposons (if memory serves), so they are listed in the same category. In the chimp genome paper, they only listed the species specific ERV’s. In that paper they saw 82 human specific ERV’s and 279 chimp specific ERV’s, that is ERV’s that reached fixation (or at least a common presence) in each lineage after the lineages split. This means humans and chimps share more than 99% of their ERV’s.