Allan C. Wilson studied genes, proteins, and body structures of animals and humans in the US during the second half of the twentieth century. Wilson also studied human evolution. Although morphology and behaviors of humans (Homo sapiens) and great apes differ, Wilson found that they have biochemical and genetic similarities. Wilson and his colleagues calculated the time period of humans' and African apes' common ancestor. Wilson and his team also studied DNA outside of the nucleus in the cellular energy producing particles, called mitochondrial DNA (mtDNA), to study when different human groups evolved from each other.

Roy John Britten studied DNA sequences in the US in the second half of the twentieth century, and he helped discover repetitive elements in DNA sequences. Additionally, Britten helped propose models and concepts of gene regulatory networks. Britten studied the organization of repetitive elements and, analyzing data from the Human Genome Project, he found that the repetitive elements in DNA segments do not code for proteins, enzymes, or cellular parts. Britten hypothesized that repetitive elements helped cause cells to differentiate into more specific cell kinds among different organisms.

Oliver Allison Ryder studied chromosomal evolution and endangered species in efforts for wildlife conservation and preservation at the San Diego Zoo in San Diego, California. Throughout his career, Ryder studied breeding patterns of endangered species. He collected and preserved cells, tissues, and DNA from endangered and extinct species to store in the San Diego Frozen Zoo, a center for genetic research and development in San Diego, California. Ryder and his team also sequenced vertebrate genomes under the Genome 10k initiative, a collaborative international program aiming to analyze the complete genomes of over ten thousand species of vertebrate. Ryder’s research has helped preserve species, restore diminished populations of wildlife, and protect biodiversity.