Breakthroughs 1997

Abstract

Even occasional observers of the scientific scene know that this year has witnessed some incredible achievements by the worldwide research community. In fact, the incredibility itself is the noteworthy feature-things once thought to be impossible have in fact been done. Like the 4-minute mile, which was once believed to be the limit of human running capacity, preconceived limits in several scientific fields were made obsolete this year. Such advances suggest that other barriers that are acceptable by today's logic could eventually yield to persistent research. This year's work has established that somatic cell nuclear transfer can clone a wholly viable sheep from the DNA of an udder cell of an adult sheep and that home observers could follow the exploration of Mars in real time as the Pathfinder mission's Sojourner robot responded to remote commands across 119 million miles. These achievements and others are recognized in this issue as Science's Breakthroughs of the Year.