On this glorious spring day in Cambridge, England, the heraldic flags are flying from the stone towers, and I feel like I could be in the 17th century—or, as I pop into the Eagle Pub to meet University of Cambridge longevity theorist Aubrey de Grey, the 1950s. It was in this pub, after all, that James Watson and Francis Crick met regularly for lunch while they were divining the structure of DNA and where, in February 1953, Crick made his breathless announcement that they had succeeded.

Dolly, 6

The first mammal cloned from an adult cell, whose 1996 birth raised the specter of human cloning, was euthanized February 14 after developing a lung tumor. Dolly got arthritis early in life, which critics cite as evidence of cloning's potential perils. Waggishly named for Dolly Parton because her genesis was a mammary gland cell, the Finn Dorset sheep is now stuffed and on exhibit at the National Museum of Scotland.



Martha Chase, 75

When I first learned about the structure of DNA in an undergraduate genetics class, my instructor-a British scientist and feminist-hammered one point into our heads: James Watson and Francis Crick did not discover the famous double helix alone. The x-ray photograph that led to their breakthrough came from the lab of a little known King's College scientist named Rosalind Franklin. No one gave her credit for her work, my instructor said, so Franklin died in scientific obscurity.