[
Trends Genet,
1997]
Focused studies on model organisms with favorable features have been important for advancing many areas of biology. Nematodes have been a successful model for analyzing development. Can they also be used to study evolution? Paul Sternberg and his present and former colleagues are attempting to answer this question by studying variation of that well-described little structure, the nematode vulva. Their efforts have been well rewarded. Two recent publications extend a series of papers showing a surprising degree of evolutionary variability in vulval development among species. Could it be that comparison of nematode species will prove to be as powerful for penetrating the intimate mechanisms of evolutionary change as analysis of mutant nematodes has been to understanding mechanisms of development?