My suspicion is that DNA is not just a data storage, copying and transmittal system, it also manages some sort of information processing as well.

That, as I understand it, is RNA's job.

Also possibly germane: a story yesterday on All Things Considered, regarding genes related to susceptibility to Type 2 diabetes being located in regions thought to be "junk DNA"; that is, areas on the genome that were presumed not to be transcribed.

I also suspect that there are other means for genetic material to be communicated other than sexually.

The most common method of that kind of transference is viruses. There's a underlying reason why we call the computer counterpart (the digital analog?) by the same name. Prions (such as are responsible for scrapies a.k.a. Kreutzfeld-Jakob, or BSE a.k.a. Mad Cow) are another example, more insidious both in the time that elapses until their invasion becomes manifest, and in that all they are is fragments of DNA.

Texas still simmers with a political controversy surrounding a vaccine for human papilloma virus (HPV), known to cause certain types of cervical cancer. If that's not a tie-in between disease and asexual DNA transfer, then I'm missing something. [By "asexual" I'm avoiding the fact that HPV is often sexually transmitted from female to female by the vector of a male who, lacking the target, is immune to the disease (but see also genital herpes, another effect of HPV)].

While I'm here....

I think you and Marcia are pretty much dead-on about environmental factors vis-a-vis cancer. Without anything more than a gut feeling, I suspect similar causes for other recent endemic syndromes, diseases and other trends, such as ADHD and reproductive difficulty. The rise in asthma among urban children is a no-brainer by comparison.

Evolution works on time scales we usually characterize as 'geological'. Sure, a random point mutation that turns out to be beneficial begins with one individual, and can occur at any moment... but it takes generations for the resultant gene to permeate the pool. On that scale, industrial civilization has appeared way too recently for any genome, let alone the human one, to respond to its toxic pressures. Except, of course, the bacteria and viruses. In their case, environmental 'toxins' are the drugs we invent. Resistant 'strains', a.k.a. sub-species, haven't taken over, but they're becoming more prevalent.

Mass extinctions in the geological record teach that the key to evolutionary response is the length of a generation compared to the rapidity and severity of environmental change.