Genomics is a branch of biology focused on the structure, function, evolution, and mapping of genomes, the complete set of DNA in the single cell of an organism. Sequencing a genome means determining the order of its chemical sub-units. Scientists use these sequences to map and catalog human genetic variation to improve our understanding of human biology, disease susceptibility, and drug response.
As the cost of genetic sequencing has fallen rapidly in recent years, concerns have increased about inaccurate or misunderstood results, violations of genetic privacy, and misuse of genetic databases. Though direct-to-consumer genetic testing has become a highly publicized industry, many experts express considerable skepticism about its usefulness, either for health conditions or ancestry information. Genetic sequencing is also increasingly used in police work, since DNA in even small amounts of blood, saliva, or other biological materials left at a crime scene can identify or exonerate a suspect. However, police DNA databases, which in many jurisdictions include people who have been arrested for but never convicted of a crime, raise concerns about privacy, potential civil liberties violations, and racial discrimination.