2011 Science News of the Year: Life

Multicellular life from a test tube

In less than two months, yeast in a test tube evolved from single-celled life to bristly multicellular structures. The new, snowflakelike forms act like multicellular organisms, reproducing by splitting when they reach large sizes and evolving further in response to harsh conditions, William Ratcliff of the University of Minnesota, Twin Cities reported in Norman, Okla.,