Yes really. You were quite clear - if science can't infer biological engineering then it can't explain biological observations. I took your sentence, changed the domain without changing the logic or relationships, and the result was clearly dumb. This is one technique of demonstrating fallacious arguments.
science probably is capable of detecting the signature of intelligent agents on a given phenomena.
And I have challenged you to demonstrate this for us. I have explained the form necessary. Why won't you do it?
in rejecting a "design hypothesis" in biology, you're essentially making an argument from ignorance.
I have been very clear over several posts. I reject ID as science because it does not have the proper form. Once that hurdle is cleared, which you have conspicuously failed to do although I have challenged you to do it several times now, then we can compare it to other theories using other criteria.
First off, it's important to note that the argument in question was a discussion of one possible outcome of a test of the ability of science to detect design.
You're misrepresenting this argument by overstating its claims. Considering the context of the statement, it is not fallacious, though I suspect that you just don't like the logical implications. It's rather obvious that if a discipline is incapable of telling the difference between hypotheses X and Y, then any claim that "it was X and not Y" is by definition unreliable. In the case of biology, if we assume it's impossible to detect the presence of engineering even when we know it happened, then it follows directly that scientific declarations of "it was not designed" are untrustworthy.
And I have challenged you to demonstrate this for us. I have explained the form necessary. Why won't you do it?
Consider the case of the insulin-producing bacterium. Suppose the I hypothesize a designer is responsible. To test that hypothesis, I would predict that the signature of genetic engineering would show up as an "out of place" gene in otherwise "normal" bacterial DNA (I could do a DNA comparison to show this). I can detect that the bacteria produce human insulin, so I could compare the "out of place" gene sequence against the known human insulin sequence. If my hypothesis is correct, then I would expect to find an excellent match. Now, since we're aware of the techniques associated with recombinant DNA, the presence of the human insulin gene sequence in an otherwise unremarkable bacterial DNA supports the hypothesis that a designer was involved in this case.
QED. There's your test. And I suspect that you were already well aware of the details.