anmarine evolutionary perspective ecology » Marine Ecology. ISSN 0173-9565 ORIGINAL ARTICLE Charles Darwin and marine biology Philip S. Rainbow Department of Zoology, Natural History Museum, London, UK Keywords Abstract Barnacle; Beagle; coral reefs; Darwin; Grant; Lyell; transmutation; unlformltarlanlsm. In a celebration of the 200th anniversary of his birth in 1809, this short essay explores the influence of marine biology on Charles Darwin,vice and versa. Correspondence Darwin made his first forays into the world of marine biology as a medical stu­ Philip S. Rainbow, D epartm ent of Zoology, dent in Edinburgh from 1825 to 1827. He came under the influence there of Natural History M useum , London SW7 5BD, the Lamarckian Robert Grant, and developed an understanding of the simple UK. organisation of the early developmental stages of marine invertebrates. Yet Dar­ E-mail: [email protected] win balked at Lamarckian transmutation. The voyage ofBeagle the led to Dar­ Accepted: 17 November 2010 win’s perceptive theory of the origin of coral reefs, an origin still mainly accepted today. This theory was steeped in the uniformitarianism of the geolo­ doi : 1 0 .1 1 1 1/j. 1439-0485.2010.00421 .x gist Lyell, depending on the slow, gradual growth of billions of coral polyps keeping pace with slow sinking of land to produce an atoll. Prom 1846 to 1854 Darwin revolutionised the understanding of barnacles, producing monographs still relevant today. His barnacle studies gave him the credibility to pronounce on the origin of species; he found great variation in morphology, and a series of related species with remarkable reproductive adaptation culminating in the presence of dwarf males. Barnacles showed him an evolutionary narrative laid out before him, and contributed greatly to his qualification and confidence to write with authority on the origin of species. Born in Shrewsbury on 12 Pebruary 1809, Charles Robertto carry out his external hospital study in Edinburgh Darwin could hardly have been said to have had the sea (Desmond & Moore 1991). Charles, however, became in his blood, but as a child he was an inveterate collectordisillusioned with his medical studies as he experienced of objects such as shells and birds eggs and developed anthe drudgery of his lectures and poor quality of his lec­ early interest in natural history. By his teens, hunting hadturers, and then the distress of clinical studies with become Charles’ passion, and in 1825 his exasperated associated blood, gore and suffering. Initial diligence father, the well respected local doctor Robert Darwin, gave way to the sampling of student life. On his own came to utter the oft-quoted prediction ‘You care forin his second year, Darwin found a diversion in marine nothing but shooting, dogs, and rat-catching, and youbiology. will be a disgrace to yourself and all your family’ (Des­ In November 1826, Charles Darwin joined the Plinian mond & Moore 1991). Strong action was needed to halt Society, an undergraduate group discussing natural his­ Charles’ aimless way of life and so, following his father tory and antiquarian researches, and occasionally going and elder brother Erasmus, medicine was chosen as the on collecting expeditions together. This proved a safety required remedy. valve from medicine, and, over the academic year, Darwin In October 1825, Charles Darwin, aged 16, found accompanied his Plinian friends on zoological walks on himself enrolled in the University of Edinburgh to studythe shores of the Firth of Forth, and ventured out on medicine, accompanied for the first year by Erasmus trawlers fishing at sea. He became familiar with a host of who, although a medical student at Cambridge, was able marine invertebrates previously strange to him, including 130 Marine Ecology32 (Suppl. 1 ) (2011 ) 130-134 © 2011 Blackwell Verlag GmbH Rainbow Charles Darwin and marine biology sponges, soft corals Alcyonium( digitatum), sea slugs founded as London University in 1826, admitting stu­ (Tritonia hombergi), polychaetes (the sea mouseAphrodite dents regardless of religion and gender, a secular alterna­ aculeata) and bryozoans(Flustra foliacea). tive to Oxford and Cambridge. London University was At this time Darwin came under the influence and clearly a more suitable venue for Grant’s seditious views mentorship of a man who would be key to the laterthan God-fearing Edinburgh. development of Darwin’s ideas on evolution. RobertThe 2 years at Edinburgh convinced Charles Darwin Edward Grant was a marine invertebrate zoologist and athat medicine was not for him, and in 1827 he left Edin­ fellow Plinian, living in Edinburgh on a decreasing legacyburgh a disappointed man: he did not like medicine, nor from his late father (Desmond & Moore 1991). Grant the men who pursued it; he had found no qualities in became Darwin’s unofficial tutor on marine invertebrates,professors to generate long-lasting respect (even Grant teaching him to make observations and to dissect speci­had disappointed him); and he was not ready to be a mens. Through Grant, Darwin developed an understand­transmutationist or be labelled a radical like his grandfa­ ing of animal development and the simple organisation ofther, Erasmus Darwin (Browne 1995). Medicine was not the early life-history stages of particular invertebrates. for him, but he now had little choice - the family fell Grant was an expert on sponges recognised by his peers,back on the typical safety net for second sons, the Church as exemplified by the naming of the newly erected spongeof England. So from 1827 to 1831, Charles Darwin found genus Grantia in his honour by John Fleming in 1828; himself at Christ’s College at the University of Cambridge the common local spongeSpongia compressa, the purse on the first stage of his journey to Holy Orders. There sponge, becameGrantia compressa. It was Grant who was still room for natural history, now under the influ­ coined the name ‘Porifera’ for the sponges. ence of John Henslow, the Professor of Botany, and for After working with Grant, Darwin (aged 18) gave a talk geology under the influence of Adam Sedgwick, Professor to the Plinian Society on 17 March 1827, showing that of Geology. the larvae of the bryozoanFlustra foliacea use cilia for However, there was no more immediate access to mar­ locomotion and that the black markings (sea pepper­ine biology for Darwin until the portentous year of 1831. corns) on the shells of oysters are the eggs of the marine Then Henslow introduced Darwin to Robert FitzRoy, leech Pontobdella muricata. A triumph for a budding captain of HMSBeagle, who subsequently invited to Dar­ marine biologist but, according to Darwin’s daughterwin to join a voyage around the world as a self-financing Elenrietta, Darwin had been scooped 3 days earlier bygentleman naturalist. The voyage lasted from December Grant in a talk to the more formal (graduate) student 1831 to October 1836. Darwin regularly sent back natural society, the Wernerian Natural History Society - an intro­history and geology collections which gained him a scien­ duction for Darwin to ‘the jealousy of scientific men’tific reputation in his absence, and the voyage changed (Browne 1995). his life for ever. Grant, however, represented something more - sedition In January 1835, Darwin collected many specimens of a personified (Desmond & Moore 1991). Grant was a fran­ large intertidal gastropod mollusc on a shore in the Cho­ cophile who had studied anatomy and embryology innos archipelago, Chile, a collection not considered even France with Geoffroy Saint-Hilaire. Correspondingly,worthy of reference in several editions of Darwin’s journal Grant was a Lamarckian, more openly so later, for hisof the voyage (Darwin 1839). The mollusc concerned was views were still forming at this time. Lamarck (1809) used a muricid gastropod,Concholepas concholepas (as Conc­ the term ‘transmutation’ for his theory that described the holepas peruviana), the shells of which were riddled with altering of one species into another. Lamarck did notcavities containing minute animals, no bigger than pin­ propose common ancestry but considered that complexheads. These were to be later identified as boring barna­ forms transmutated from simple forms of life created cles, and these were also destined to affect Darwin’s continuously by spontaneous generation. As a Lamarck­future life enormously. ian, Grant arranged life into chains, considering that the Before leaving on theBeagle, Darwin had been greatly origins of animals and plants lay in the simplest forms;influenced by Sir Charles Lyell, a leading geologist of the and that the natural ordering, simple to complex, oftime, who had published the first edition of hisPrinciples sponges represented the historical order of appearance ofo f Geology in three volumes (1830, 1832, 1833). Lyell was sponges. Thus Grant directly exposed Darwin to evolu­a believer in uniformitarianism, a philosophy claiming tionary theory, with the associated concepts of structuralthat geological and biological forces have always been homology and unity of plan with similar organs presentworking in the same way and at the same intensity over in different animals. Grant went on in 1827 to becomeages. This view of uniformitarianism was in conflict with Professor of Comparative Anatomy for life (1874) at Uni­the then-prevailing theory of catastrophism, which con­ versity College, London. University College had beensidered that the earth experienced major changes only as Marine Ecology32 (Suppl. 1) (2011) 130-134 © 2011 Blackwell Verlag GmbH 131 Charles Darwin and marine biology Rainbow a result of large catastrophic events. A key considerationunstudied for 6 years. Robert Grant, now in London, was whether the earth was old enough to experience volunteered to help, particularly with ‘lower animals’, but large-scale changes in any other way, but Lyell thought it was turned down by Darwin who had become a compe­ necessary to create a vast time scale for Earth’s history to tent (and competing) coral expert, given his interest in vouch for fossil remains of extinct species, excluding sud­coral reef formation.