While his prolific mating is a clear sign of the king's success, this unique gorilla's extensive family tree grew out of tragic circumstances.

Molecular biologist Peter Savolainen of the Royal Institute of Technology in Stockholm, Sweden, and his colleagues have studied the origins of domestic dogs using hair samples and mitochondrial DNA.

To help ensure the survival of endangered whooping cranes, Operation Migration maintains an artificial breeding program that prepares chicks for adulthood.

Sharing 99 percent of our DNA, chimps have been used in the study of infectious diseases, gene therapy, vaccine development, reproduction, and anatomy.

Many creatures undergo startling transformations as they mature. But we are just beginning to understand the genetic blueprints that guide these changes.