Query Id: tqa2:L_0432
Run: dangnt-nlp
Darwin discusses morphology, including the importance of homologous structures. He says, "What can be more curious than that the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat, should all be constructed on the same pattern, and should include the same bones, in the same relative positions?" This made no sense under doctrines of independent creation of species, as even Richard Owen had admitted, but the "explanation is manifest on the theory of the natural selection of successive slight modifications" showing common descent. He notes that animals of the same class often have extremely similar embryos. Darwin discusses rudimentary organs, such as the wings of flightless birds and the rudiments of pelvis and leg bones found in some snakes. He remarks that some rudimentary organs, such as teeth in baleen whales, are found only in embryonic stages. These factors also supported his theory of descent with modification.
Darwin refers specifically to the distribution of the species rheas, and to that of the Galápagos tortoises and mockingbirds. He mentions his years of work on his theory, and the arrival of Wallace at the same conclusion, which led him to "publish this Abstract" of his incomplete work. He outlines his ideas, and sets out the essence of his theory:
James Moore describes how people try to get Darwin on the side of their view of nature. In The Origin of Species nature is seen as being at war, but also likened to a web of complex relations. Here, Darwin gave people a basis for urging humans not to take control of nature but to cooperate with it. In popular imagination, a scientific theory has a single fixed meaning, but in reality it becomes cultural property, and is usable by different interested parties.
Chapter X examines whether patterns in the fossil record are better explained by common descent and branching evolution through natural selection, than by the individual creation of fixed species. Darwin expected species to change slowly, but not at the same rate – some organisms such as Lingula were unchanged since the earliest fossils. The pace of natural selection would depend on variability and change in the environment. This distanced his theory from Lamarckian laws of inevitable progress. It has been argued that this anticipated the punctuated equilibrium hypothesis, but other scholars have preferred to emphasise Darwin's commitment to gradualism. He cited Richard Owen's findings that the earliest members of a class were a few simple and generalised species with characteristics intermediate between modern forms, and were followed by increasingly diverse and specialised forms, matching the branching of common descent from an ancestor. Patterns of extinction matched his theory, with related groups of species having a continued existence until extinction, then not reappearing. Recently extinct species were more similar to living species than those from earlier eras, and as he had seen in South America, and William Clift had shown in Australia, fossils from recent geological periods resembled species still living in the same area.
The Voyage of the Beagle is the title most commonly given to the book written by Charles Darwin and published in 1839 as his Journal and Remarks, bringing him considerable fame and respect. This was the third volume of The Narrative of the Voyages of H.M. Ships Adventure and Beagle, the other volumes of which were written or edited by the commanders of the ships. Journal and Remarks covers Darwin's part in the second survey expedition of the ship HMS Beagle. Due to the popularity of Darwin's account, the publisher reissued it later in 1839 as Darwin's Journal of Researches, and the revised second edition published in 1845 used this title. A republication of the book in 1905 introduced the title The Voyage of the "Beagle", by which it is now best known.
Beagle was originally scheduled to leave on 24 October 1831 but because of delays in her preparations the departure was delayed until December. Setting forth on what was to become a ground-breaking scientific expedition she departed from Devonport on 10 December. Due to bad weather her first stop was just a few miles ahead, at Barn Pool, on the west side of Plymouth Sound,. The Beagle left anchorage from Barn Pool on 27 December, passing the nearby town of Plymouth. After completing extensive surveys in South America she returned via New Zealand, Sydney, Hobart Town (6 February 1836), to Falmouth, Cornwall, England on 2 October 1836.
The recurring shipmates were journalist and presenter Lex Runderkamp, biologists Dirk Draulans and Sarah Darwin (who is the great-great-granddaughter of Charles Darwin), the artist Anthony Smith and the writer Redmond O'Hanlon. Apart from them several other more or less well-known people joined the voyage and some joined for only one or more legs of the voyage, including some other descendants of Charles Darwin.
Near the end of 1831, while the Beagle was still being fitted out at Devonport in preparation for sailing, the recently graduated Charles Darwin arrived in Plymouth to take up the opportunity of sailing on the ship as a self-funded gentleman naturalist who would be a companion to the captain while the ship was at sea, and who would make his own expeditions inland while the ship's crew was surveying the coasts. He told his sister that he had "breakfasted yesterday with a Mr. Harris whom I like more than anybody I have seen.— He has written a great deal on Electricity", and wrote to tell his university tutor John Stevens Henslow about his progress, noting that he had met "one or two pleasant people, foremost of whom is Mr. Thunder & Lightning Harris, whom I daresay you have heard of." In his diary he noted that on the evening of 21 November he attended a "popular lecture from Mr Harris on his lightning conductors" at the Athenaeum. Harris used an "Electric machine" for a thunder cloud and a tub of water for the sea, then with "a toy for a line of battle ship he showed the whole process of it being struck by lightning & most satisfactorily proved how completely his plan protects the vessel from any bad consequences. This plan consists in having plates of Copper folding over each other, let in in the masts & yards & so connected to the water beneath. — The principle, from which these advantages are derived, owes its utility, to the fact that the Electric fluid is weakened by being transmitted over a large surface to such an extent that no effects are perceived, even when the mast is struck by the lightning. — The Beagle is fitted with conductors on this plan; it is very probable, we shall be the means of trying & I hope proving the utility of its effects."
Giant tortoises are characteristic reptiles that are found on two groups of tropical islands: the Aldabra Atoll in Seychelles and the Galapagos Islands in Ecuador (a population at the Mascarene Islands was exterminated by the 1900s) . These tortoises can weigh as much as and can grow to be long. Giant tortoises originally made their way to islands from the mainland; for example, Aldabra Atoll and Mascarenes giant tortoises are related to Madagascar tortoises while Galapagos giant tortoises are related to Ecuador mainland tortoises. This phenomenon of excessive growth is known as islands gigantism or insular gigantism. It occurs when the size of the animals that are isolated on an islands increases dramatically in comparison to their mainland relatives. This is due to several factors such as relaxed predation pressure, competitive release, or as an adaptation to increased environmental fluctuations on islands. These animals belong to an ancient group of reptiles, appearing about 250 million years ago. By the Upper Cretaceous, 70 or 80 million years ago, some had already become gigantic. About 1 million years ago tortoises reached the Galápagos Islands. Most of the gigantic species began to disappear about 100,000 years ago. Only 250 years ago there were at least 20 species and subspecies in islands of the Indian Ocean and 14 or 15 subspecies in the Galápagos Islands.
Giant tortoises are among the world's longest-living animals, with an average lifespan of 100 years or more. The Madagascar radiated tortoise Tu'i Malila was 188 at death in Tonga in 1965. Harriet (initially thought to be one of the three Galápagos tortoises brought back to England from Charles Darwin's Beagle voyage but later shown to be from an island not even visited by Darwin) was reported by the Australia Zoo to be 176 years old when she died in 2006. Also, on 23 March 2006, an Aldabra giant tortoise named Adwaita died at Alipore Zoological Gardens in Kolkata. He was brought to the zoo in the 1870s from the estate of Lord Clive and is thought to have been around 255 years old when he died. Around the time of its discovery, they were caught for food in such large quantities that they became virtually extinct by 1900. Giant tortoises are now under strict conservation laws and are categorised as threatened species.
The Seychelles giant tortoise (A. g. hololissa) is broad, flattened on the back and with raised scutes, it is usually a brownish-grey color.In comparison, the true Aldabra tortoise (A. g. gigantea) is a roundly-domed, black-colored species.
Darwin's finches (also known as the Galápagos finches) are a group of about fifteen species of passerine birds. They are often classified as the subfamily Geospizinae or tribe Geospizini. They belong to the tanager family and are not closely related to the true finches. The closest known relative of the Galápagos finches is Tiaris obscura. They were first collected by Charles Darwin on the Galápagos Islands during the second voyage of the Beagle. Apart from the Cocos finch, which is from Cocos Island, the others are found only on the Galápagos Islands.
Darwin's finches are different closely related species which Darwin discovered on the Galapagos Islands. Darwin's voyage on the Beagle, and the finches in particular, are known to have influenced his thinking so that he would later produce a basic theory of evolution by natural selection. Darwin reasoned that there had to be a common ancestor. Later, extensive research was done by Peter and Rosemary Grant. The birds are all about the same size (10–20 cm). They mainly differ in the form of the beak. The beak is adapted to the food they eat. The birds are all brownish or black. They have short rounded wings and a rounded tail that often appears cocked to one side. Most male finch mature to a solid black color, while the females mature to a drab grayish color. Exceptions are made for the Vegetarian and Tree Finches the males never become completely black rather they have a black head, neck and upper breast. Warbler, Woodpecker and Mangrove Finches have more of an olive color.
The term "Darwin's finches" was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book Darwin's Finches. David Lack based his analysis on the large collection of museum specimens collected by the 1905–06 Galápagos expedition of the California Academy of Sciences, to whom Lack dedicated his 1947 book. The birds vary in size from 10 to 20 cm and weigh between 8 and 38 grams. The smallest are the warbler-finches and the largest is the vegetarian finch. The most important differences between species are in the size and shape of their beaks, and the beaks are highly adapted to different food sources. The birds are all dull-coloured.
There have been big advances in plant breeding and animal breeding, such as crop hybridization, GMOs (genetically modified organisms) and artificial insemination of livestock. Further down the food chain came innovations in food processing and food distribution (e.g. frozen foods).
A breeding program is the planned breeding of a group of animals or plants, usually involving at least several individuals and extending over several generations. There are a couple of breeding methods, such as artificial (which is man made) and natural (it occurs on its own, which is very rare).
One major technique of plant breeding is selection, the process of selectively propagating plants with desirable characteristics and eliminating or "culling" those with less desirable characteristics.
The Darwin Industry has also stretched to many related figures before, during and after Darwin's time. Darwin's grandfather Erasmus Darwin has been a subject of great interest, and the broad philosophical currents of Naturphilosophie and Romanticism in science during the 19th century are still being explored. Studies of Jean-Baptiste Lamarck, Georges Cuvier, Charles Lyell, Thomas Henry Huxley, Richard Owen, Alfred Russel Wallace and many others have all been influenced to a greater or lesser degree by the work of the Darwin Industry. Because of the unusual hybrid nature of The Origin of Species as both a popular and scientific work, one major focus of the Darwin Industry has been the role of popularization and education in the spread of Darwin's theory: the popular work of Huxley, Ernst Haeckel, Herbert Spencer, and most dramatically, Robert Chambers (who wrote the 1844 sensation Vestiges of the Natural History of Creation), is increasingly seen as important in its own right in the history of evolutionary thought.
Others basing their studies of reproductive ecology on Darwin's evolutionary approach included Friedrich Hildebrand and Severin Axell in Europe, Asa Gray and Charles Robertson in North America. In Italy, Federigo Delpino adopted the theory of descent but like Sprengel had a teleological approach and explained the mechanisms of flowers by the intervention of a "psychovitalistic intelligence". Delpino classified flowers on the basis of the pollinators they attracted, and coined many of the terms still in use such as pollination syndrome and ornithophily. There was an enormous increase in knowledge during this period. In 1874, Asa Gray paid tribute to Darwin's work on orchids for explaining "all these and other extraordinary structures, as well as of the arrangement of blossoms in general, and even the very meaning and need of sexual propagation". He credited Darwin with establishing the understanding that "Nature abhors close fertilization".
See the publication of Darwin's theory for the resulting developments, in the context of his life, work and outside influences at the time.