Simplicity was always the key to Caenorhabditis elegans' success. This transparent worm, just a millimetre in length, thrives throughout the world yet is among the most primitive organisms imaginable.
On the face of it, C. elegans sounds a pretty unrewarding creature to study. Nevertheless, some 1,000 scientists spend their time working with it and about 5,500 scientific papers have been penned in its honour.
Now three experts - Sydney Brenner, Sir John Sulston and Robert Horvitz - have won the Nobel prize for physiology or medicine for their research on this lowly worm.
Brenner, one of the pioneers of genetics, started it all in the 1960s when he gained the backing of the Medical Research Council for a project to explore the development of multicellular organisms. C. elegans was ideal for the task Brenner envisaged - it has just 959 somatic cells in its body, grows to adulthood in three days, is a hermaphrodite so mutants can be easily isolated and is small enough to study under the electron microscope.
The research at Cambridge's MRC laboratory of molecular biology would ultimately enable a tiny worm to tell science about a much more complex cousin - humankind.
C. elegans shares many essential biological characteristics with us. It is conceived as a single cell that develops into a complex organism that ages and then dies. It has muscles, a digestive tract, a nervous system and even the ability to learn.
Brenner extracted a genetic map from the worm. Sulston derived its entire cell lineage and discovered the key process of programmed cell death. Horvitz identified the specific genes responsible for this process and then found that many were also carrying out similar functions in humans.
Today, C. elegans ' simplicity is helping scientists to understand ageing and sex, memory and the immune system, diabetes and cancer.