LOL! The old bait and switch. Rather than scientific evidence, you're now demanding something else, which is actually not necessary to support the hypothesis.
Your other comments simply confirm my point. You're raising "scientific" objections to the possibility of finding specific, observable signs of genetic engineering. You claim without proof that it would be impossible to show intelligent activity. Of course, the flip side of that coin is that it would therefore be likewise impossible to show that the phenomenon was a result of random processes.
Observable phenomena were your original criterion for a scientific hypothesis, and the burden would certainly be on the hypothesizer to to produce compelling evidence in intelligent intervention; and you seem to think it's impossible to isolate it. Then again, those other folks who can trace genes back for a long time don't seem to suffer from the difficulties you bring up.... So perhaps your complaint has more to do with personal emotional attachments, than it reflects any real scientific concerns you might have.
But the fact remains -- by your complaints you simply confirm the validity of the ID hypothesis, AND you kindly offer encouragement to those who might claim to be able to scientifically isolate "ID signal" from "naturalistic noise."
Unlike an actual object that one is determining if it was the result of an intelligent action, what actual object does I.D. point to other than “biological complexity”?
Well, the ability to digest citrate is biological complexity. Was it caused by the actions of an intelligent agent?
Everyone in the ID movement is welcome to look for evidence of genetic engineering. It's not even expensive since genome data is online.
When humans engineer organisms -- and I presume you would include this as an example of intelligent design -- they tend to insert genes from one species to another, even crossing the lines at the level of kingdom.
This results in organisms that do not fit in a nested hierarchy. So ID supporters might spend their time looking for breaks in the nested hierarchy. ERVs would be a logical starting place.