Müller was born in the village of Windischholzhausen, near ErfurtinThuringia, Germany, the son of a minister. Müller had what would be seen today as a normal scientific education at the universities of Berlin (earning a BSc in Botany) and Greifswald, culminating in a PhD in Biology. He subsequently decided to study medicine. As a medical student, he began to question religion and in 1846 became an atheist, joining the Free Congregations and supporting free love. Despite completing the course, he did not graduate because he refused to swear the graduation oath, which contained the phrase "so help me God and his sacred Gospel".
Müller was disappointed by the failure of the Prussian Revolution in 1848, fearing implications for his life and career. As a result, he emigrated to Brazil in 1852, with his brother August and their wives, to join Hermann Blumenau's new colony in the State of Santa Catarina. In Brazil, Müller became a farmer, doctor, teacher and biologist. During this time, he studied the natural history of the sub-tropicalAtlantic forest, around the Itajaí River valley.
Müller gained an official teaching post, and spent a decade teaching mathematics at a college in Desterro.[4][5] The college was taken over by the Jesuits, and Müller (though retaining his salary) returned to the Itajaí River valley. He negotiated a number of botanical activities with the provincial government and spent the next nine years doing botanical research and advising farmers. In 1876 he was appointed as a Travelling Naturalist to the National Museum in Rio de Janeiro.
In his retirement years, Müller received many offers of support and offers of financial help. He was one of many naturalists to visit and work in South America during the nineteenth century, but was the only one to settle in Brazil for the rest of his life. A statue of Müller was erected in Blumenau in 1929.[6]
During his life Müller published over 70 papers in English and Portuguese, and also in German-language periodicals. The topics covered a range of natural topics from entomology, marine biology and botany.
Müllerian mimicry is named after and discovered by him. This phenomenon concerns the resemblance between two or more unpalatable species which are protected from predators capable of learning. The protection is often a noxious chemical, perhaps gained from the larva eating a particular plant; or it may be a sting or other defence. It is an advantage for such potential prey to advertise their status in a way clearly perceptible to their predators; this is called aposematicorwarning coloration. The principle is of wide application, but in Müller's case the prey were butterflies, and the predators usually birdsorreptiles.[7]
In Müllerian mimicry, an advantage is gained when unpalatable species resemble each other, especially when the predator has a good memory for colour (as birds, for instance, do have). Thus one trial may work to dissuade a bird from several species of butterfly which all have the same warning coloration. Müller and other naturalists believed that such systems of mimicry could only come about by means of natural selection, and all of them wrote about it.
Another of Müller's discoveries were the Müllerian bodies in the flowering plant genus Cecropia. Müller was able to show that the small bodies at the petiole-bases of Cecropia are food bodies and are used by protecting ants of the genus Azteca which inhabit the hollow stems of these fast growing trees.
Much of Müller's botany was stimulated by the series of botanical works published by Darwin. After Darwin's Fertilisation of Orchids (1862) he spent years of work on orchids, sending observations to his brother Hermann and to Darwin. Darwin used some of this work in his second edition of 1877, and Hermann later became famous for his work on pollination. On Climbing plants (1867) Müller lent a letter to Darwin listing 40 genera of climbing plants classified by their method of climbing. The next few months saw more observations, which Darwin had translated and published as Müller's first paper in English.[8] As a botanist, Fritz Müller is denoted by the author abbreviationF.J.Müll. when citingabotanical name.[9]
Müller became a strong supporter of Charles Darwin. He wrote Für Darwin in 1864, arguing that Darwin's theory of evolutionbynatural selection was correct, and that Brazilian crustaceans and their larvae could be affected by adaptations at any growth stage. Müller sent a copy to Darwin, who had the book privately translated for his own use.[10] A later translation into English, with some additional material by Müller, was made by W.S. Dallas, and was published as Facts and Arguments for Darwin in 1869.
^West, David A. 2003. Fritz Müller: a naturalist in Brazil. Blacksburg: Pocahontas Press.
^Desterro has been replaced by the modern city of Florianópolis (= Floripa), which is on the mainland as well as the Island of Santa Catarina. The island is about 120 miles SE of São Paulo, about 330 miles SE of Rio de Janeiro, and about 300 miles north of Montevideo on the Rio de la Plata.
^Henry Bates notes the "splendid climate of Desterro" and its links with German settlements. Bates H.W. 1882. Central America, the West Indies and South America. 2nd revised ed., Stanford, London. p 432, 436 and map of the Seaports of Brazil opp p427.
^Bates H.W. 1882. Central America, the West Indies and South America. 2nd revised ed., Stanford, London. p408 et seq
^Müller, Fritz 1878. Über die Vortheile der Mimicry bei Schmetterlingen. Zoologischer Anzeiger1, 54–55.
Müller F. 1879. Ituna and Thyridia: a remarkable case of mimicry in butterflies. (transl. R. Meldola) Proceedings of the Entomological Society of London 20-29.
^Müller, Fritz 1867. Notes on some of the climbing-plants near Desterro in South Brazil. J Linn Soc (Botany)9, 344-9 (read 7 Dec 1865).
Alfred Möller, 1920. Fritz Müller. Werke, Briefe und Leben [virtually the sole biographical source for this significant biologist]
Cezar Zillig, 1997. Dear Mr. Darwin. A intimidade da correspondência entre Fritz Müller e Charles Darwin. Sky/Anima Comunicação e Design, São Paulo, 241 pp. [letters between Müller and Darwin, with very interesting comments on the life of Fritz Müller. In Portuguese]
Andreas Daum, Wissenschaftspopularisierung im 19. Jahrhundert: Bürgerliche Kultur, naturwissenschaftliche Bildung und die deutsche Öffentlichkeit, 1848–1914. Munich: Oldenbourg, 1998, ISBN3-486-56337-8, [contains a short biography and much information on the contemporary context, including Darwinism in Germany, Haeckel, Krause, etc.]
David A. West, 2003. Fritz Müller: A Naturalist in Brazil. Blacksburg: Pocahontas Press. ISBN0-936015-92-6 [modern, and most welcome, though the biographical information rests almost entirely on Möller's book. West adds excellent summaries and assessments of Müller's biological work]
