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.

Torsten Nils Wiesel studied visual information processing and development in the US during the twentieth century. He performed multiple experiments on cats in which he sewed one of their eyes shut and monitored the response of the cat’s visual system after opening the sutured eye. For his work on visual processing, Wiesel received the Nobel Prize in Physiology or Medicine in 1981 along with David Hubel and Roger Sperry. Wiesel determined the critical period during which the visual system of a mammal develops and studied how impairment at that stage of development can cause permanent damage to the neural pathways of the eye, allowing later researchers and surgeons to study the treatment of congenital vision disorders.

Max Ludwig Henning Delbrick applied his knowledge of theoretical physics to biological systems such as bacterial viruses called bacteriophages, or phages, and gene replication during the twentieth century in Germany and the US. Delbrück demonstrated that bacteria undergo random genetic mutations to resist phage infections. Those findings linked bacterial genetics to the genetics of higher organisms. In the mid-twentieth century, Delbrück helped start the Phage Group and Phage Course in the US, which further organized phage research. Delbrück also contributed to the DNA replication debate that culminated in the 1958 Meselson-Stahl experiment, which demonstrated how organisms replicate their genetic information. For his work with phages, Delbrück earned part of the 1969 Nobel Prize for Physiology or Medicine. Delbrück's work helped shape and establish new fields in molecular biology and genetics to investigate the laws of inheritance and development.

Etienne Stephane Tarnier was a physician who worked with premature infants in France during the nineteenth century. He worked at the Maternité Port-Royal in Paris, France, a hospital for poor pregnant women. Tarnier developed and introduced prototypes of infant incubators to the Maternité in 1881. Tarnier's incubators became standard in neonatal care, especially for premature infants, enabling doctors to save many such infants that previously would have died.

Harvey Karman was an abortionist, inventor, and activist for safe abortion techniques in the US during the twentieth century. Karman developed the Karman cannula, a flexible soft tube used for vacuum aspiration abortions. Karman traveled extensively throughout the US to educate healthcare providers on how to administer safe abortions. He also traveled to Bangladesh, India, China, and other developing nations to promote safe and simple abortion techniques that anyone could perform without previous medical training. As of 2017, Karman’s abortion technique and cannula continue to be widely used throughout the world for terminating early pregnancies. Karman challenged laws prohibiting abortion in the US prior to 1973 and worked to create methods for abortion that were safer, less expensive, and easier to administer than previous abortion techniques.

Conrad Hal Waddington was an embryologist and theoretical biologist. His early experimental work investigated aspects of embryonic induction and the properties of the organizer first identified by Hans Spemann and Hilde Mangold, while his later studies focused on genetic assimilation. Waddington is probably best known for developing the concept of the epigenetic landscape, and he also held significant interest in many different areas ranging from the visual arts and poetry to philosophy. Throughout his career, Waddington maintained that the arts were integral to science, and he continued to draw inspiration from the arts for his own work.

Annie Wood Besant was a social activist who advocated for women’s access to birth control as well as marriage reform, labor reform, and Indian Nationalism in the nineteenth century in England and India. In her early career, Besant was involved in various social and political advocacy organizations including the National Secular Society, the Malthusian League, and the Fabian Society. Besant gave many public lectures and authored various articles in support of secularism, workers’ rights and unionization, and women’s rights. In 1877, Besant and her colleague Charles Bradlaugh republished the pamphlet The Fruits of Philosophy, by Charles Knowlton, on reproduction and contraception. Besant and Bradlaugh were tried for violating the obscenity law that prohibited the publication of obscene material, including sex and contraception. Later in her life, she converted to theosophy and moved to India where she joined the Theosophical Society. In India, Besant campaigned for Indian self-rule and became the president of the Indian National Congress. Besant, through republication of The Fruits of Philosophy and many public lectures and writings on women’s rights, expanded public knowledge of birth control.

Leon Chesley studied hypertension, or high blood pressure, in pregnant women during the mid-twentieth century. Chesley studied preeclampsia and eclampsia, two hypertensive disorders found in approximately five percent of all US pregnancies. In New Jersey and New York, Chesley devoted over forty years to researching preeclampsia and eclampsia. Chesley conducted several long-term studies using the same group of women beginning from their pregnancies. Chesley’s multi-decade research led to more accurate diagnosis of preeclampsia and eclampsia in pregnant women and significantly reduced the mortality of pregnant women due to hypertensive diseases.

Charles Bradlaugh was as a political and social activist in the seventeenth century in England. He held leadership positions in various organizations focused on social and political activism including the Reform League, the London Secular Society, the newspaper National Reformer, and the National Secular Society. Throughout his career, Bradlaugh advocated for better conditions for the working poor, and for the separation of government and religion. The British government prosecuted him numerous times for violating laws prohibiting the publication, sale, and transmission of antireligious, antigovernment, and obscene materials. In 1877, Bradlaugh and another secularist, Annie Besant, republished The Fruits of Philosophy, a pamphlet about contraceptive techniques originally whose author was physician Charles Knowlton. In the nineteenth century, individuals did not have access to information on sex, reproduction, and contraception, as much of society argued such information encouraged immoral behavior. Bradlaugh and Besant were tried for publishing information on sexual anatomy, conception, and methods to control reproduction. Bradlaugh expanded public knowledge of reproduction and contraception, and initiated the process of dismantling the obscenity laws.

Fortunio Liceti studied natural philosophy and medicine in Italy during the first half of the seventeenth century. Liceti wrote greater than seventy works on a wide range of topics, including the human soul, reproduction, and birth defects observed in animals and human infants. In the seventeenth century, people commonly addressed birth defects using superstition and considered them as signs of evil, possibly caused by spiritual or supernatural entities. Liceti described infants with birth defects as prodigies and monsters to be admired and studied rather than feared. Liceti’s works established monsters as a possible subject of scientific inquiry and served as models for the future study of birth defects, a field later called teratology. Liceti was one of the first scholars to attempt to systematically categorize birth defects based on their causes, including multiple causes unrelated to the supernatural.