So how do you explain the way the ERVs show up in various species of ape, as though there was a family tree with people and chimps on the same branch?
Are you willing to claim that the hypothetical designer is constrained by the rule that any ERV in both new world and old world monkeys must also be in every species of ape, including ourselves?
By the rule that any ERV in both orangutans and gibbons, which live in Asia must also be in every species of African ape, including ourselves?
If the hypothetical designer is constrained by the rules summarized in the diagram, why? Explain in detail.
If it isn't, then why do we find this pattern?
This is just the primates. The same sort of rules apply everywhere: artiodactyls, carnivores, you name it.
Here is another essay from TalkOrigins with a family tree for artiodactyls; among other things, it indicates that a genetic marker found in both pigs and whales will also be found in hippos and cows.
With all these examples, how reasonable is doubting "common descent"?
These four constitute the argument:
ltr21q22.3
ltr41
ltr32
ltr21q22.2
There aren't any notations for retroviral DNA on the branch between chimps and humans, so claiming humans more closely related to chimps than Gorillas isn't supported by your chart.
The classic primate "family tree" excluding a few early branches looks like this: