The promise is tantalizing, offering hardier food crops and new tools to fight human disease. From modest organisms such as yeast, fungus and flies to the majestic human genome, the biology of life is emerging in greater detail than ever before. Much work remains to be done. It's like you've got all the boards and nails, but you don't have anything built yet. The gene myth Scientists have studied genes for decades, finding a single gene that controls eye color in flies, for example, or causes cystic fibrosis in humans.
Most organisms have thousands of genes, and most remain unidentified.
In addition, most interesting characteristics depend on many genes working in concert. To better understand the struggle, consider DNA as the book of life. For humans, it stretches to 3 billion letters. The strands are made up of four different types of molecules, known by the initials A, G, C and T. Each creature has DNA in its cells, and the differences in DNA are what make the difference between a fish and a tree, a bacteria and a human being. The announcement that made headlines in June meant that scientists had roughly mapped out the entire sequence of As, Gs, Cs and Ts for a human being.