Using the humble pea, an obscure Austrian monk named Gregor Johann Mendel proved that living things pass their characteristics to later generations with mathematical regularityalmost as if the formula for each trait were conveyed in a separate little package. Last week, more than a century later, a team of young Harvard researchers reported that they had finally zeroed in on that Mendelian package. For the first time, science had isolated a single gene.
Viral Assistance. Although the gene has long been recognized as the basic unit of heredity, it has been only 26 years since molecular biologists learned that the gene is...