If not for Nobel laureates Thomas Hunt Morgan, Eric R. Kandel, and Sydney Brenner, the notion of a general behavioral model might seem odd. Behaviors, after all, are determined by an animal's evolutionary history and ecological niche. They are often idiosyncratic, shared in detail only by closely related species.
But, thanks to Morgan's research in the early 20th century, and Kandel's and Brenner's work over the past 35 years, the fly Drosophila melanogaster, the mollusk Aplysia californica, and the worm Caenorhabditis elegans have become general behavioral models. The newest member of the club is the mouse.
This quartet yields broadly applicable behavioral findings for two reasons: First, these animals are unusually amenable to cellular and molecular experimentation; second, such experimentation has turned up certain genes, proteins, and cells that underlie behavior across many species. Evolution did not "completely reinvent the wheel and come up with a new set of molecular ...
