Pioneering molecular biologist Roy J. Britten dies

Roy J. Britten, a pioneering molecular biologist who discovered the crucial fact that humans and animals have multiple copies of some DNA segments, has died. He was 92.

The California Institute of Technology in Pasadena, where Britten performed research for decades, said Wednesday that Britten died of pancreatic cancer on Jan. 21 at his Costa Mesa home.

Britten discovered the repetitive DNA sequences in 1968. The sequences don't provide blueprints for genes but they are critical for animal development.

Britten and colleague Eric Davidson also helped demonstrate that gene expression - the way certain genes are switched on - during development plays a crucial evolutionary role, such as determining whether an animal has legs or fins. That work laid the foundation for the field of evolutionary biology.