Literatura científica selecionada sobre o tema "Beagle Expedition (1831-1836) cct"

Charles Darwin and Alfred Russel Wallace independently arrived at similar theories of evolution by natural selection as announced in 1858. Both men had undertaken transformative travels that provided data for their conclusions. This article compares and contrasts their published travel narratives and shows how it impacted their interpretations. While Darwin’s voyage aboard the H.M.S. Beagle (1831-1836) was largely in the southern hemisphere temperate zone, Wallace’s (1854-1862) island-hopping expedition was confined to the Malayan (Indonesian) Archipelago. Although very similar, there were slight differences in their resulting theories of natural selection. The debates that would divide them on this issue related especially to sexual dimorphism in birds and butterflies, with examples from their travels. Both men, however, perceived the profound differences between the Australian fauna and that of the rest of the world. Wallace was able to identify the exact boundary between these two different “creations,” later dubbed “Wallace’s Line.”

The 1831–1836 voyage of H.M.S. Beagle under Captain Robert FitzRoy launched Charles Darwin's entry into the world of geology with two pioneering publications on oceanic islands to his credit. Best known is Darwin's 1842 contribution on the theory of atoll development from the subsidence of volcanic islands and coeval upward growth of coral reefs. This work can be linked, in part, to the ten days during which the Beagle visited the Keeling (Cocos) Islands. The subsequent and lesser known of Darwin's parallel contributions is his 1844 summary on all the volcanic islands visited during the expedition, including Santiago (Cape Verde Islands), Terceira (Azores), St. Paul's Rocks, Fernando Noronha, Ascension, St. Helena, the Galápagos Islands, Tahiti, and Mauritius. Ostensibly, the centerpiece of the 1844 volume is Darwin's extensive coverage of Ascension based on the five days spent there in 1836. However, Darwin had many more days at his disposal in the Galápagos and ‘St. Jago’ (Santiago), where the Beagle stopped in the Cape Verde Islands at the outset and again near the end of the voyage. The volcanic islands where Darwin spent the most time were in the Galápagos (thirty-five days) and the Cape Verdes (twenty-nine days). In particular, those island groups make an interesting comparison with respect to the development of Darwin's ideas on tectonic uplift based on basalt flows with inter-bedded limestone formations. Chance played a huge role in what Darwin saw and did not see during his island travels. The initial visit to the Cape Verde islands was instrumental in shaping Darwin's earliest vision of a book on volcanic islands, but his time there was entirely fortuitous due to a forced change in FitzRoy's plan for a stay in the Canary Islands. Although Darwin was on the look out for limestone formations in the Galápagos islands comparable to those on Santiago in the Cape Verdes, he missed finding them due only to the vagaries of FitzRoy's charting schedule in the Galápagos. This overview looks at limestone distribution in the Cape Verde and Galápagos archipelagos as now understood and speculates on how a wider knowledge of both regions may have influenced Darwin's thinking on global patterns of island uplift and subsidence.

Joseph Beete Jukes studied geology at Cambridge University under Adam Sedgwick at a time when Lyell's Principles of Geology (1830-1833) revitalized the subject and when Darwin was engaged in the voyage of the Beagle (1831-1836). He owed his first professional position in Newfoundland to the patronage of Sedgwick, Lyell, Darwin and others both in Cambridge and in London, and his appointment as naturalist on H.M.S. Fly (1842-1846), to survey the Great Barrier Reef of Australia to these same supporters. Darwin published his coral reef theory in 1838, and this provided the intellectual basis for Jukes's work. In New South Wales Jukes was met by another of Sedgwick's pupils, W. B. Clarke, the leading earth scientist in the colony. Clarke himself had recently met J. D. Dana, the reef geologist on the Wilkes Expedition, who was also enthusiastic for Darwin's theory. Jukes's reef work was characterised both by Darwin's theoretical insights, which he supported but did not extend, and Sedgwick's pragmatic commitment to empirical investigation. Jukes's work in Australia, and indeed his subsequent career until his tragic death in 1869, illustrates both the intellectual and the practical consequences of his early association with the Cambridge geology school, and the way in which his mentor Sedgwick (and through him the leading geologists of the time - Darwin, Lyell and Murchison) determined his career and influenced his views. His Great Barrier Reef research, published in 1847, as well as his association with Clarke, helped to mould the development of geology in colonial New South Wales into the mould of metropolitan science in general and that of Sedgwick's Cambridge in particular.