The handy-dandy kitchen device.

In gray tree frogs, the duration of males' mating calls is correlated with enhanced genetic fitness among offspring (A. M. Welch et al., Reports, 19 June, p. 1928). Perhaps the same genes that enable some frogs to sustain longer calls also confer a survival advantage to their young (E. Pennisi, Research News, 19 June, p. 1837). If so, this may be an example of a more general, but underappreciated, evolutionary process, in which fitness is increased through the combined effect of multiple inherited characteristics. In the case of gray tree frogs, a characteristic with little if any apparent adaptive significance (longer calls) may be associated with other traits that improve overall fitness by a possible instance of genetic covariation.