Simple answer: Because DNA/RNA is an information code like xml, and information codes do not simply form up out of the blue from inanimate matter, for no particular reason.
I have a degree in computer science and I'm familiar with information theory. I'm not going to belittle you for a statement like this because I've seen several science fiction authors make the same mistake. In fact, there were actual scientific theories at one time that memories were stored in strands of so-called "memory RNA". This however has proven false. Still though, the fact that computers use binary (base 2) while DNA seems to be base 4 is inductively enticing...so, people still fall into that trap.
Thinking about DNA in terms of functional abstraction rather than information content is not as intuitive. People have a hard time imaging that someone could know how to build something without knowing what it was supposed to look like when it was finished. This notion seems absurd and yet you see it all the time in nature. This is probably related to a lack of understanding of perception and consciousness which most intelligent people have no concept of. I don't know that this is the place to discuss it but I like fruit flies because their behavior is quite similar to that of single celled organisms even though they have vastly more brain power. This behavior is simple environmental response. Other organisms like nematodes and flatworms do this too but fruit flies are about the most complex organisms I can think of that behave this way. But I don't want to hijack the thread so that's all I'll say about it.
Our entire biosphere is driven by information.
This sounds similar to the Gaia hypothesis which although imaginative has been created without evidence. Versions of this theory are sometimes mentioned by Creationists as proof of a grand design.
The fruit fly experiments, designed specifically to prove for all time the validity of the concept of macroevolution and the theory of evolution, failed so spectacularly and unambiguously that a number of prominent scientists at the time denounced evolution.
Yes, this claim has been made a number of times. It still remains a claim though rather than proof. It should be possible to create two separate species from a parent fruit fly population. However, I am not aware of any experiment that has ever tried to do this. If this experiment had been tried several times and had failed then you would indeed have strong evidence against evolution. However, since this experiment has never been done, I'm not sure where this imaginary proof would be coming from. To the best of my ability to try to understand the line of reasoning of such claims, it appears to be something like the following: If an organism can be selectively bred to include harmful characteristics then this conflicts with my assumption that evolution always makes organisms better. Therefore, evolution--and not my assumption--must be wrong.
The closest I can think of where you begin to get into an evolutionary framework is where characteristics interfere with reproduction. This is because anything that constrains reproduction also constrains gene flow and this could eventually lead to separate species. Obvious examples of this include the varying populations of black bear around the world as well as the European bison compared to the American bison. Another example that comes to mind is the forest versus the savanna elephant (and possibly the desert elephant) even those these are genetically closely related.
That failure was due to the fact that the only information there ever was in that picture was the information for a fruit fly. The experiments proved in no uncertain terms that information for any sort of a meaningfully new creature could not be created by any combination of mutation and selection, as the theory of evolution demands.
Actually, this is demonstrably false. Obvious examples include pericentric inversions, centromere splitting/telomere joining, and chromosome duplication. Other examples include allotropes. Anyway this claim seems to be based on a bounded notion of species characteristics when in reality species have no definite characteristic boundaries. For example, the African wild dog is a different species from the domestic dog. They actually have differing numbers of chromosomes. However, it would be very difficult to point to any specific characteristic that they do not share other than the fact that domestic dogs make eye contact.
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