Henry Walter Bates FRS FLS FGS (Leicester, 8 February 1825 – London, 16 February 1892) was an English naturalist and explorer who gave the first scientific account of mimicry in animals. He was most famous for his expedition to the Rainforests of the Amazon with Alfred Russel Wallace in 1848. Wallace returned in 1852, but lost his collection in a shipwreck. When Bates arrived home in 1859 after a full eleven years, he had sent back over 14,712 species (mostly of insects) of which 8,000 were new to science.

Bates was born in Leicester and, like Wallace, T.H. Huxley and some other British scientists of the time, he had no formal education in science, and left school at 12. He came from a literate middle-class family and taught himself mainly by reading (like Wallace, Huxley and Herbert Spencer, he was an auto-didact). At 13 he became apprenticed to a hosier. He joined the Mechanics' Institute (which had a library), studied in his spare time, and collected insects in Charnwood Forest. In 1843 he had a short paper on beetles published in the journal Zoologist.

Henry Walter (1611–1678?) was a Welsh Anglican priest who became a Puritan.

Walter was born in the parish of St. Arvans, Monmouthshire, south Wales in 1611 and studied at the University of Oxford, matriculating as a member of Jesus College, Oxford in 1633 and obtaining his Bachelor of Civil Law degree in the same year. He was ordained as a priest in the Church of England, and became curate of Mounton, not far from St. Arvans, in 1639 through his brother's influence. However, Walter's religious views diverged from those of the Church of England, becoming aligned with those of the non-conformist William Wroth, who was also based in Monmouthshire; Wroth made Walter the main executor of his will. During the English Civil War, Walter seems to have left Monmouthshire for London. In 1646, he was one of three Puritan clergymen sent by the House of Commons to preach in Welsh in Wales, and he was the first name on the list of clerical commissioners approving clergy appointments in Wales under the Act for the Propagation of the Gospel in 1650. In 1653, Walter became vicar of St Woolos in Newport, but he was ejected from there in 1662 after the Restoration. In 1672, he was given a licence to minister in Llantarnam and later inspired the Independent congregation in Mynyddislwyn, to whom he left some money in his will. He died sometime before 8 August 1678.

Walter Bates (14 March 1760 – 11 February 1842) was an American who, through actions of his family and himself, came to Nova Scotia to live under British rule.

Bates was born on a farm in eastern Connecticut and may have stayed there except for the activities of his elder brothers on the Tory side of the American War of Independence. That situation forced him to shelter himself among the British sympathizers on Long Island where he taught school. In 1783, he accepted a British offer of 200 acres (0.81 km²) of land in Nova Scotia plus two years’ supplies and transportation to his new homestead at Kingston. He was part of the first contingent of settlers who sailed in that year. The ship was the Union_(ship) and he later wrote of his experiences.

Charles Robert Darwin, FRS (12 February 1809 – 19 April 1882) was an English naturalist. He established that all species of life have descended over time from common ancestors, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.

Darwin published his theory with compelling evidence for evolution in his 1859 book On the Origin of Species, overcoming scientific rejection of earlier concepts of transmutation of species. By the 1870s the scientific community and much of the general public had accepted evolution as a fact. However, many favoured competing explanations and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution. In modified form, Darwin's scientific discovery is the unifying theory of the life sciences, explaining the diversity of life.

Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. Studies at the University of Cambridge encouraged his passion for natural science. His five-year voyage on HMS Beagle established him as an eminent geologist whose observations and theories supported Charles Lyell's uniformitarian ideas, and publication of his journal of the voyage made him famous as a popular author.