Genetics, Overview

This chapter provides an overview of genetics, which is the study of the transmission of and variation in hereditary traits. In the case of genetic analyses of natural animal populations at the level of organisms or above, most studies draw their inferences from the relative degree of difference in consanguinity among individuals, populations, and species. The confidence with which such inferences can be relied upon depends on the accuracy of the genetic estimates derived from the collected genetic data, which in turn is linked to the amount of genetic data as well as the underlying assumptions made during the analysis of the data. The most common source of genomic DNA is from soft tissue samples. Soft tissue samples are readily available from dead animals, e.g., stranded or killed specimens. The advantage of PCR-based techniques is that only a minute amount of target DNA is required, and hence adequate amounts of DNA are readily obtained from skin biopsies, sloughed skin, hair, and even feces, which can be collected from free-ranging marine mammals with relative ease. © 2009