GENETIC ENGINEERING Scientists are trying to figure out the entire three billion-letter human genome with high precision as a prelude to figuring out eventually what protein each gene produces and for what purpose. It all started in 1866 when Austrian botanist and monk Gregor Mendel proposed basic laws of heredity based on crossbreeding experiments with pea plants. His findings, published in a local natural-history journal, were largely ignored for more than thirty years. In 1910 U.S. biologist Thomas Hunt Morgan’s experiment with fruit flies reveal that some genetically determined traits are sex linked. His work also confirms