This chapter reviews the sexually dimorphic nature of meiosis in mammalian species, since many aspects of recombination depend on whether the gamete is proceeding through spermatogenesis or oogenesis. Since meiotic recombination occurs at prophase during fetal development in mammalian females, few investigations of human recombination have focused on this stage. Linkage disequilibrium (LD) analysis provides a powerful tool for the generation of high resolution genetic maps. LD mapping does not require analysis of multiple generations in a family. Rather it is a simple assessment of haplotype blocks among different individuals. Fortunately, with improvements in immunostaining techniques and the increasing availability of antibodies capable of detecting meiosis-acting proteins, it has now become possible to analyze the processes of pairing, synapsis, and recombination in human fetal oocytes. Advances in mapping methodology have led to the generation of high-resolution male and female genetic maps.