Word: molecular
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Advances in molecular biology and genomic medicine are increasing the odds that compounds dreamed up by scientists make it from the lab to the pharmacy. Here are some of the latest candidates, either just approved by the Food and Drug Administration (FDA) or under review. ?DIABETES If you're a diabetic and the daily injections of insulin are torture, then get ready for some relief. Pfizer received FDA approval in January to market the first inhaled insulin, Exubera, which should become available around midyear. The powdered insulin, taken just before meals, is released into the mouth and lungs through...
...cells of modern Native Americans: mitochondrial DNA, which resides outside the nuclei of cells and is passed down only through the mother; and the Y chromosome, which is passed down only from father to son. Since DNA changes subtly over the generations, it serves as a sort of molecular clock, and by measuring differences between populations, you can gauge when they were part of the same group...
...least you can try. Those molecular clocks are still rather crude. "The mitochondrial DNA signals a migration up to 30,000 years ago," says research geneticist Michael Hammer of the University of Arizona. "But the Y suggests that it occurred within the last 20,000 years." That's quite a discrepancy. Nevertheless, Hammer believes that the evidence is consistent with a single pulse of migration...
Theodore Schurr, director of the University of Pennsylvania's Laboratory of Molecular Anthropology, thinks there could have been many migrations. "It looks like there may have been one primary migration, but certain genetic markers are more prevalent in North America than in South America," Schurr explains, suggesting secondary waves. At this point, there's no definitive proof of either idea, but the evidence and logic lean toward multiple migrations. "If one migration made it over," Dillehay, now at Vanderbilt University, asks rhetorically, "why not more...
...absolute terms, of course, the U.S. is still the world leader in scientific research. A half-century's worth of momentum is tough to derail. Yet, says Shirley Tilghman, president of Princeton and a molecular biologist, "there's still reason to feel some urgency. The world is not standing still while we take a pause...