One of the evidences for common ancestry of humans and chimpanzees is 'shared ERVs', (the same endogenous retrovirus in humans as in chimpanzees). A potential falsification of that evidence would be matching ERVs that violated the nested hierarchy of species; In other words, if an ERV in the human genome had a match in a species other than chimpanzees, our closest biological relative. In other words, a common ancestor from the time before the common ancestor of humans and chimps would have had the ERV insertion and among its descendants a branch would split off away from the branch of the chimpanzee-human ancestor, so that the chimpanzee-human common ancesor branch should be carrying that ERV. Therefore, any ERV in any other primate that matches an ERV in humans must be in the chimpanzee genome also.
The tree collapses if either the human or the chimpanzee has an ERV matching that of some other primate, since if humans and chimpanzees allegedly share a common ancestor, how is it that the chimpanzee or the human is missing that ERV.
Ah, but not so fast. The proponents of common ancestry may not be so quick to give up this device.
It turns out the Rhesus monkey (Rhesus Macaque/Macaca mulatta), has a closer matching ERV-K with humans differing greatly from chimpanzees.
"The study by Romano and colleagues being published this week on PLoS Onerevealed that human ERV-K had a similar demographic signature to that of the rhesus monkey, both differing greatly from that of the chimpanzee."
However, the difference between the Rhesus-Human ERV-K from that of the chimpanzee ERV was explained away as a matter of demographics and:
"The data suggested that the humans and rhesus have been purging ERV-K copies from their genomes while the chimpanzee ERV-K population kept the signature of increasing numbers of ERV-K amplification in the genome of ancestral primates during the last 20 million years."
Here is the main article from PLoS ONE: (well not all of it, just a teeny snippet)
"Nevertheless, the elevated dispersal of both Homo and Macaca compared to Pan may be an important factor that could explain the similarities in the demographic histories of HERV-K and RhERV-K.
Unlike HERV-K and RhERV-K, the chimpanzee ERV-K demographic signal was characterized by a far larger effective population size. Assuming that host dynamics impacts on ERV-K numbers, the recent flat curve of Pan skyline after 6 MYBP agrees with the lack of evidence for severe bottlenecks in the Pan lineage and a 3.2 times larger effective ancestral population size. The latter could have facilitated the maintenance of a higher number of integrated elements observed in the chimpanzee genome, because of a weaker effect of genetic drift, although the wide HPD values caution against over-interpretation."
OK, this is dissappointing. It appeared the bar had been met, a violation of the nested hierarchy. But its hard to get a slam dunk in the evolution/creation debate.