George McDonald Church studied DNA from living and from extinct species in the US during the twentieth and twenty-first centuries. Church helped to develop and refine techniques with which to describe the complete sequence of all the DNA nucleotides in an organism's genome, techniques such as multiplex sequencing, polony sequencing, and nanopore sequencing. Church also contributed to the Human Genome Project, and in 2005 he helped start a company, the Personal Genome Project. Church proposed to use DNA from extinct species to clone and breed new organisms from those species.

The Human Genome Diversity Project, or HGDP, was an effort led by US-based scientists to collect DNA from members of Indigenous communities living around the world for the purpose of understanding human history, migration, and evolution. Launched in 1991, and led by Luca Cavalli-Sforza, a scientist at Stanford University in Stanford, California, the HGDP initially had the support of US funding agencies. However, the project eventually lost that support when representatives of Indigenous groups protested the project as being exploitative and fellow scientists accused it of racism. Though the project ultimately failed to collect most of the samples it had originally planned, the HGDP was one of the first attempts by scientists to catalogue worldwide human genetic variation, and the DNA samples it did collect formed the basis of many subsequent research studies concerned with understanding human genetic variation and migration patterns.