Scientific American (june 2003)

TEST TUBE BABIES AND CLONES • THE NEXT STEP FOR PHYSICS Mad Cow–Type Plague Strikes Wild Deer JUNE 2003 WWW.SCIAM.COM COMPUTER, HEAL THYSELF AN END TO DISASTROUS CRASHES? Martian Mysteries How Chain Letters Evolve COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. $4.95 contents june 2003 SCIENTIFIC AMERICAN Volume 288 Number 6 features EMERGING DISEASES 38 Shoot This Deer BY PHILIP YAM Wild deer in parts of the U.S. are dying of a contagious wasting illness similar to mad cow disease. Unchecked, it might endanger humans and livestock. ASTRONOMY 44 The Unearthly Landscapes of Mars BY ARDEN L. ALBEE The weird dynamics shaping the surface of the Red Planet reveal that Mars is not just a colder, drier Earth. COMPUTING 54 Self-Repairing Computers BY ARMANDO FOX AND DAVID PATTERSON Systems inevitably fail. The key to reliable computing is building systems that crash gracefully and recover quickly. BIOTECHNOLOGY 62 Pandora’s Baby BY ROBIN MARANTZ HENIG If today’s social arguments against human cloning sound familiar, it’s because foes of in vitro fertilization raised them 20 years ago. PHYSICS 68 The Dawn of Physics beyond the Standard Model 54 The key to crash recovery BY GORDON KANE After 30 years of triumphs, the Standard Model of particle physics is at the height of its success. Something even better is on the way. INFORMATION SCIENCE 76 Chain Letters and Evolutionary Histories BY CHARLES H. BENNETT, MING LI AND BIN MA Studies of chain letters show how to infer the family tree of anything that evolves, from genes to languages to plagiarized schoolwork. www.sciam.com SCIENTIFIC AMERICAN COPYRIGHT 2003 SCIENTIFIC AMERICAN, INC. 5 SCIENTIFIC AMERICAN Volum