tuck was the first of many to submit this important milestone in arguably the world's most important scientific endeavor. The Human Genome Project has completed mapping its first entire chromosome, number 22. Second-smallest of our 23 chromosomes, some of 22's genes can cause "heart defects, immune system disorders, cancers, schizophrenia and mental retardation." Portion of its DNA which is "junk" (encodes no protein): 42%. Read it at your favorite source: CNN, MSNBC, the Boston Globe, the Christian Science Monitor, the AP, or Reuters.