The Book of Life, Chapter 22

Researchers passed a milestone in the race to identify the approximately 100,000 genes in the human genome Wednesday when an international team of scientists announced they'd completed the first genetic map of a human chromosome. The group identified and mapped out 545 genes in the 33 million sets of protein "letters" that spell out chromosome number 22, the second smallest of the 23 matched pairs that make up the human DNA code. While analyzing the millions of proteins in even one chromosome is an impressive feat, it's only a fraction of the three billion or so proteins that make up the human genome. Scientists in the federally funded Human Genome Project, prodded by competition from rival groups such as Craig Venter's Celera (which, unlike the government project, hopes to turn a tidy profit by locking up patents from its genetic mapping) say they will have all the research done by 2003.

That's when the real fun begins. While some real-world applications could take years to develop, scientists hope the mapping will eventually lead to an understanding of how our chromosomes work, and conversely, when and how they fail or mutate. Irregularities in gene sequences are believed to cause such ailments as brain disorders and cancer; understanding those irregularities could help prevent or cure them. Of course, along with the power to manipulate genes comes some heavy ethical questions. If you thought genetically modified foods were controversial, just wait till the debate turns to genetically modified people.