David silber writes: Are there any geneticists out there. I am not a geneticist, but I am a doctor. I have had graduate level medical genetics courses. There is most certainly enough inactive DNA to carry genetic markers. HLA-risk factor lab testing as well other electrophoresis lab testing is based on these genetic markers. We use genetic markers to find people who have everything from Chrones Disease to Retinitis Pigmentosa. I believe it is close to 90% of genetic material is 'carrier' , spacer or marker material. I don't remember he exact percentage and I'm too lazy to look it up, but I know I'm darn close. The big news of mapping the human genome is geared towards finding these markers and the defective genes they represent. Keep an eye on the news in the next ten years, breakthroughs are just around the corner in carotid artery disease and eye disease. John D. Barbato,O.D. "I torch my soul to show that I am pure deep inside my heart.", Billy Corgin, smashing punkins