Thomas Henry Huxley was born on May 4, 1825, in Ealing, Middlesex, England.

He was an English biologist, anthropologist, educator, and advocate of agnosticism. Despite his lack of early formal education, he studied mechanical engineering and science, and read books on many subjects. His self-taught study of German enabled his future proficiency in the biological research conducted in Germany, and a talent for drawing aided his later zoological studies. In 1841, he apprenticed with his brother-in-law, a physician John Godwin Scott in London. He continued his self-education and in 1842, he received a scholarship to Charing Cross Hospital and published his first scientific paper in 1845. With mounting debts, he never finished his studies and applied to the Royal Navy where he was made Assistant Surgeon to HMS Rattlesnake on a voyage of discovery and surveying to New Guinea and Australia. The Royal Society published several of his papers in its Philosophical Transactions. Upon his return to England in 1850, he was elected a Fellow of the Royal Society and in 1851, he not only received its medal but was elected to its Council. In 1854, he became Professor of Natural History at the Royal School of Mines and naturalist to the British Geological Survey in 1855. He was Fullerian Professor at the Royal Institution (1855–1858; 1865–1867); Hunterian Professor at the Royal College of Surgeons (1863–1869); President of the British Association for the Advancement of Science (1869–1870); President of the Quekett Microscopical Club (1878); President of the Royal Society (1883–1885); Inspector of Fisheries (1881–1885); and President of the Marine Biological Association (1884–1890). He was elected a member of the American Philosophical Society in 1869. In recognition of his many public services, he was given a pension by the state and was appointed Privy Councillor in 1892. He was also known for his support of Charles Darwin's theories.

In 1855, he married Henrietta Anne Heathorn (1826–1914). He died on June 29, 1895, in Eastbourne, Sussex, England.

Alpheus Hyatt was born on April 5, 1838, in Washington, D.C.

He was an American zoologist and paleontologist. He briefly attended the Maryland Military Academy and Yale University, and after graduating from Harvard University in 1862, he enlisted in the Massachusetts Volunteer Infantry for the Civil War, emerging with the rank of captain. After the war, he worked at the Essex Institute (now the Peabody Essex Museum) in Salem, Massachusetts. He co-founded American Naturalist and served as its editor from 1867 to 1870. He became a professor of paleontology and zoology at the Massachusetts Institute of Technology in 1870, where he taught for eighteen years, and was a professor of biology and zoology at Boston University from 1877 until his death in 1902. He also served as curator of the Boston Society of Natural History. In 1875, he was elected a member of the National Academy of Sciences. In 1898, he received the honorary degree of LL.D. from Brown University.

In 1867, he married Audella "Della" Beebe (1840–1932). He died on January 15, 1902, in Cambridge, Massachusetts.