Hooker, Joseph Dalton

Hooker, Joseph Dalton

British Botanist 1817-1911

Joseph Dalton Hooker was one of the leading British botanists of the late nineteenth century. He was born in Halesworth, Sussex, and was the son of another great British botanist, Sir William Jackson Hooker (1785-1865). Hooker graduated with a degree in medicine from Glasgow University, where his father was a professor of botany. His father eventually held the position of Director of Kew Gardens in London and, through his leadership, made it one of the finest botanical gardens in the world, with an extensive collection of plants from the British colonies. In 1855 Joseph Hooker became assistant director of Kew Garden and became director when his father died in 1865.

Hooker is best known for his work in taxonomy, the science of classification, and plant geography, the science of plant distribution. These primary interests were shaped by his participation in a famous four-year scientific expedition under the command of Captain James Clark Ross that sought to determine the position of the south magnetic pole. Hooker was aboard the H.M.S. Erebus, one of the two expeditionary ships that left England in 1839. Although he was appointed the ship's assistant surgeon, Hooker made extensive collections of botanical material from geographic regions not previously explored, including the Great Ice Barrier and several oceanic islands such as Tasmania, the Falklands, and New Zealand. Hooker was struck by the similarity of the floras of these regions. He explained these similarities by adopting a land-bridge theory, one that postulated the existence of a lost circumpolar continent. It was on the basis of these observations that Hooker began to adopt an evolutionary explanation for the similarities. His work was summarized in a collection known as The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror. The publication of its six quarto volumes between 1853 and 1855 established Hooker as one of the great botanists of the nineteenth century.

Hooker continued to travel and explore through much of his life, and in the process compiled many floras. He also collected many plant specimens, which he introduced to England. He is especially well known for his stunning, previously unknown species of Rhododendron that he discovered in the Sikkim region of the Himalayas. Many of these are still grown in Kew Gardens. He also made notable contributions in pure morphology, including classic studies on the unusual plant Welwitschia (1863).

Hooker is also known for his close friendship with the most famous naturalist of his day, Charles Darwin (1809-1882). In fact, Darwin trusted Hooker enough to confide his radical new theory of descent with modification by means of natural selection (later called evolution by means of natural selection) in 1844, some fifteen years before Darwin wrote On the Origin of Species (1859). Although Hooker knew of this theory well in advance of its publication, he was not convinced of its importance until his own observations of the distribution of plants were completed. Darwin and Hooker remained close friends until Darwin's death. Hooker led a long and productive life and was knighted in 1877. He died in Sunningdale, England, in 1911.

see also Biogeography; Botanical Gardens and Arboreta; Curator of a Botanical Garden; Darwin, Charles; Taxonomist; Taxonomy.

Vassiliki Betty Smocovitis

Bibliography

Allen, M. The Hookers of Kew, 1785-1911. London: Michael Joseph, 1967.

Desmond, R. "Joseph Hooker." In Dictionary of Scientific Biography, Vol. 6. New York: Scribner's Sons, 1970.

Huxley, Leonard. Life and Letters of Sir Joseph Dalton Hooker. London: John Murray, 1918.

Turrill, William Bertram. Joseph Dalton Hooker. London: Thomas Nelson and Sons Ltd., 1964.