Sophisticated methods that make better use of the various types of information contained in genetic data have been developed. These methods can be grouped into two types of approaches: coalescent or genealogical approaches that use the genealogical information contained in DNA sequences and multilocus genotype approaches that use gametic disequilibrium information. It is important to realize that these two types of methods differ not only in the type of information they use, but also on the nature of the parameters they estimate. Coalescent methods (and those based on summary statistics) estimate long-term evolutionary parameters, whereas multilocus genotype methods estimate short-term ecological parameters. This chapter discusses the second type of approaches, those based on multilocus genotype data. It first provides some examples of applications of classical population genetic approaches and their limitations. Then, the chapter introduces multilocus genotype approaches with an account of their short history and some details about their implementation followed by some examples. Finally, it discusses the need to integrate the information provided by genetic data with that coming from demographic and environmental data and provides examples of how to achieve this goal.