An organism's genome is the hereditary information encoded in its genes. Sequencing a gene or a fragment of genetic material involves determining the order of its sub-units: adenine, cytosine, guanine, and thymine.

Scientists are using individuals' genetic sequences to map and catalog human genetic variation. They hope this will help them better understand human biology, disease susceptibility, and drug response. The International HapMap Project—the largest and most ambitious of these endeavors—sequences genetic samples from people with Nigerian, Chinese, Japanese, and Mormon (United States) ancestry.

Many observers are concerned that this kind of genetic research could be used to give undue biological significance to racial differences that are produced by social arrangements. For example, lay understandings of race inform how genetic variation is introduced to the HapMap sample, how distinctions between racial groups are discussed and researched, and how we understand why particular groups suffer disproportionately from certain diseases.

These endeavors may also obscure the social and environmental causes that produce racial disparities in health outcomes.