But DNA is not a computer code, and tweaking it requires no intelligence. We see viruses modify DNA regularly, with no indication whatsoever that they were intelligently designed.
No, it doesn't. Not according to the definition provided by Shannon et. al., and if you mean to use a different definition, then you really need to define the term, because I know how computer science defines "information", and if that's the definition we're using, you are very wrong. All that's required to increase the information in a code is to make the code longer or to increase the alphabet involved, both of which are trivially possible without intelligence.
I'm not sure what you mean by "increased noticed multiple acts of sophistication", could you please explain that?
You want a complex, sophisticated code? Decode a rock. The sheer intricacies that go into placing each individual atom are astounding, to the point that it absolutely dwarfs the complexity of DNA. There is so much information there, it must require a level of intelligence! Right?
You don't understand what information means.
Tiny.
The whole thing is worth watching, but if you just want the most important bits, around 3:00, then around 7:20. Even a very small advantage in fitness often is selected for.