RETURN OF THE LIVING DEAD?

Through a teardrop of ancient amber -- fossilized tree sap as hard as plastic and as translucent as glass -- the scientists beheld their quarry: a small stingless bee that shared the earth with giant mastodons. With sterile instruments and gloved hands, microbiologist Raul Cano and his student Monica Borucki proceeded with an improbable experiment. First they delicately extracted the bee's diminutive digestive tract. Then they placed the tissues in nutrient-rich broth. Within a week the mixture turned cloudy, a sign that bacterial spores, dormant inside the bee for 25 million to 40 million years, had suddenly, miraculously surged back to...