H. Robert Horvitz identified the genes that play a significant role in programmed cell death and amyotrophic lateral sclerosis (ALS); he also discovered a new receptor that responds to serotonin. His pioneering research was performed on the nematode Caenorhabditis elegans.

C.elegans is a translucent worm about 1 millimeter long. Its genetic similarity to humans has made the nematode a focus of scientific study. In 1965, Dr. Sydney Brennan was the first to decide that the tiny creature was an ideal model for the study of the genetic code because it has far fewer genes than a human being, and yet its genetic structure is remarkably similar to a human's. Within two decades, biologists around the world were studying the worm and its 1090 cells. Indeed, work on sequencing its genome assisted molecular biologists studying the human genome. Moreover, medical biologists often collaborate with worm biologists, noting, for example, that the...