Volume 30 brings readers up to date on the investigation of eminent evolutionary biologists and paleobiologists. Contributions explore such topics as + adaptation in Drosophila and the role of cytochrome P450s + Population genetics and species conservation of the cheetah + germ--layer theory + assymetry in the mammalian skeleton + genetic diversity of marine fish + the phenomenon of industrial melanism + the variation in lizard cranal kinesis. Other chapters focus on such issues as overdominance and its relation to higher mutation--rate estimates and the use of molecular clocks in determining the rate of nucleotide substitution in higher plants.