Screening allozymes has been the dominant method for analyzing genetic variation in natural populations since the 1960s and indeed for some applications it is still the most appropriate technique. However, the more recent advent of methods to investigate variation in the DNA molecule directly has increased accuracy and resolution and facilitated the investigation of different questions relevant to population genetics. This book seeks to enable researchers to analyze simultaneously various genomic components, and thus improve interpretation of their experimental data. Topics covered include allozyme electrophoresis, analysis of mitochondrial and chloroplast DNA, RFLP analysis, PCR amplification and direct sequencing, development of species specific probes, DNA fingerprinting, and statistical interpretation of data. Emphasis is on protocols that save time and expense, facilitating the screening of large numbers of samples, and in every case significant recent developments in the field are incorporated. This volume should be a useful lab manual for researchers involved in screening populations to determine variation, genetic distance, gene flow, effective population size, and other related parameters.