In short, DNA is a huge problem for evolution, not a proof. The unanswered question being: Where is the new information coming from?
Jumping into the thread a bit late, I’m afraid.
The detailed answer depends on how you define ‘information’. Rather than dive into mathematical definitions I prefer a higher level overview.
The environment contains information. Information such as “there is no light in a deep cave” or “white things are difficult to see against a snowy background”. There is a lot of information contained in any environment.
What evolution does is to
copy that information from the environment into the DNA of organisms living in that environment. Random mutations make random changes. Some of those changes are a better match for the environment while other changes are a worse match for the environment. Natural selection selects the changes that better match the environment and preferentially amplifies them into future generations. Over time this repeated process copies information into DNA.
If some fish are living in a dark cave, there will be random mutations for larger eyes, ordinary eyes or smaller eyes. Smaller eyes will be beneficial because less energy is wasted building a useless eye in a totally dark environment. Being beneficial, those mutations spread until you end up with a population of totally blind cave fish.
The environment might contain information like “snow falls in winter, not in summer”. There are many animals that change their coat colour to match: white in winter and brown in summer. Further north where snow is present in summer as well as winter, polar bears keep their white coats all year round. Further south, where winter snow is absent or negligible, animals do not change their coat colour. Information about local snowfall has been copied into those animals’ DNA.
Information from the environment is copied into DNA by an iterative process of repeated random changes and picking the best match with natural selection. That is pretty much the way that genetic computer algorithms work.