Although Darwin had privately questioned blending inheritance, he struggled with the theoretical difficulty that novel individual variations would tend to blend into a population. However, inherited variation could be seen, and Darwin's concept of selection working on a population with a range of small variations was workable. IHP Pavilion dv7-1129wm CPU Fan
t was not until the modern evolutionary synthesis in the 1930s and 1940s that a model of heredity became completely integrated with a model of variation.
Chapter VI begins by saying the next three chapters will address possible objections to the theory, the first being that often no intermediate forms between closely related species are found, though the theory implies such forms must have existed. HP Pavilion G72-b15EV CPU Fan
As Darwin noted, “Firstly, why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms? Why is not all nature in confusion, instead of the species being, as we see them, well defined?” Darwin attributed this to the competition between different forms, combined with the small number of individuals of intermediate forms, often leading to extinction of such forms. Compaq Presario CQ60-417DX CPU Fan
This difficulty can be referred to as the absence or rarity of transitional varieties in habitat space.
Another difficulty, related to the first one, is the absence or rarity of transitional varieties in time. Darwin commented that by the theory of natural selection “innumerable transitional forms must have existed,” and wondered “why do we not find them embedded in countless numbers in the crust of the earth?” HP Pavilion dv7-3080eg CPU Fan
(for further discussion of these difficulties, see Speciation#Darwin’s_Dilemma and Bernstein et al. and Michod)The rest of the chapter deals with whether natural selection could produce complex specialised structures, and the behaviours to use them, when it would be difficult to imagine how intermediate forms could be functional. Darwin said: HP Pavilion dv9233ca CPU Fan
Secondly, is it possible that an animal having, for instance, the structure and habits of a bat, could have been formed by the modification of some animal with wholly different habits? Can we believe that natural selection could produce, on the one hand, organs of trifling importance, such as the tail of a giraffe, which serves as a fly-flapper, and, on the other hand, organs of such wonderful structure, as the eye, of which we hardly as yet fully understand the inimitable perfection? HP Envy 14-1195la CPU Fan
His answer was that in many cases animals exist with intermediate structures that are functional. He presented flying squirrels, and flying lemurs as examples of how bats might have evolved from non-flying ancestors. He discussed various simple eyes found in invertebrates, starting with nothing more than an optic nerve coated with pigment, as examples of how the vertebrate eye could have evolved. Darwin concludes: HP Pavilion dv6-2115sf CPU Fan
"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."
Chapter VII (of the first edition) addresses the evolution of instincts. His examples included two he had investigated experimentally: slave-making ants and the construction of hexagonal cells by honey bees. HP Pavilion dv7-3067nr CPU Fan
Darwin noted that some species of slave-making ants were more dependent on slaves than others, and he observed that many ant species will collect and store the pupae of other species as food. He thought it reasonable that species with an extreme dependency on slave workers had evolved in incremental steps. He suggested that bees that make hexagonal cells evolved in steps from bees that made round cells, HP Pavilion dv7-1129wm CPU Fan
under pressure from natural selection to economise wax. Darwin concluded:
Finally, it may not be a logical deduction, but to my imagination it is far more satisfactory to look at such instincts as the young cuckoo ejecting its foster-brothers, —ants making slaves, —the larvæ of ichneumonidæ feeding within the live bodies of caterpillars, —not as specially endowed or created instincts, HP Pavilion G72-b15EV CPU Fan
but as small consequences of one general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die.
Chapter VIII addresses the idea that species had special characteristics that prevented hybrids from being fertile in order to preserve separately created species. HP Pavilion dv6-2140se CPU Fan
Darwin said that, far from being constant, the difficulty in producing hybrids of related species, and the viability and fertility of the hybrids, varied greatly, especially among plants. Sometimes what were widely considered to be separate species produced fertile hybrid offspring freely, and in other cases what were considered to be mere varieties of the same species could only be crossed with difficulty. SONY Vaio VGN-SZ6RXN/C CPU Fan
Darwin concluded: "Finally, then, the facts briefly given in this chapter do not seem to me opposed to, but even rather to support the view, that there is no fundamental distinction between species and varieties."
In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not have been produced by natural selection. HP Pavilion dv7-2130ev CPU Fan
He said some such features could have been by-products of adaptive changes to other features, and that often features seemed non-adaptive because their function was unknown, as shown by his book onFertilisation of Orchids that explained how their elaborate structures facilitated pollination by insects. Much of the chapter responds to George Jackson Mivart's criticisms, including his claim that features such as baleen filters in whales, ACER eMachines G520 CPU Fan
flatfish with both eyes on one side and the camouflage of stick insectscould not have evolved through natural selection because intermediate stages would not have been adaptive. Darwin proposed scenarios for the incremental evolution of each feature.
Chapter IX deals with the fact that the geologic record appears to show forms of life suddenly arising, HP Pavilion dv5-2132dx CPU Fan
without the innumerable transitional fossils expected from gradual changes. Darwin borrowed Charles Lyell's argument in Principles of Geology that the record is extremely imperfect as fossilisation is a very rare occurrence, spread over vast periods of time; since few areas had been geologically explored, there could only be fragmentary knowledge of geological formations, and fossil collections were very poor. Compaq Presario CQ60-307ea CPU Fan
Evolved local varieties which migrated into a wider area would seem to be the sudden appearance of a new species. Darwin did not expect to be able to reconstruct evolutionary history, but continuing discoveries gave him well founded hope that new finds would occasionally reveal transitional forms. To show that there had been enough time for natural selection to work slowly, HP Pavilion dv6-2010sa CPU Fan
he again cited Principles of Geology and other observations based on sedimentation and erosion, including an estimate that erosion of The Weald had taken 300 million years. The initial appearance of entire groups of well developed organisms in the oldest fossil-bearing layers, now known as the Cambrian explosion, posed a problem. Darwin had no doubt that earlier seas had swarmed with living creatures, but stated that he had no satisfactory explanation for the lack of fossils. Toshiba Satellite A40-702 CPU Fan
Fossil evidence ofpre-Cambrian life has since been found, extending the history of life back for billions of years.
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. SONY Vaio VGN-AR21B CPU Fan
The pace of natural selection would depend on variability and change in the environment. This distanced his theory from Lamarckianlaws 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. SONY Vaio VPC-EB3E1E/PI CPU Fan
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. SONY Vaio VPC-EB3E1E/WI CPU Fan
Recently extinct species were more similar to living species than those from earlier eras, and as he had seen in South America, and William Clifthad shown in Australia, fossils from recent geological periods resembled species still living in the same area.SONY Vaio VGN-FS660/W CPU Fan
Chapter XI deals with evidence from biogeography, starting with the observation that differences in flora and fauna from separate regions cannot be explained by environmental differences alone; South America, Africa, and Australia all have regions with similar climates at similar latitudes, but those regions have very different plants and animals. HP Pavilion G61-631NR CPU Fan
The species found in one area of a continent are more closely allied with species found in other regions of that same continent than to species found on other continents. Darwin noted that barriers to migration played an important role in the differences between the species of different regions. The coastal sea life of the Atlantic and Pacific sides of Central America had almost no species in common even though the Isthmus of Panama was only a few miles wide. HP Pavilion dv6560el CPU Fan
His explanation was a combination of migration and descent with modification. He went on to say: "On this principle of inheritance with modification, we can understand how it is that sections of genera, whole genera, and even families are confined to the same areas, as is so commonly and notoriously the case." Darwin explained how a volcanic island formed a few hundred miles from a continent might be colonised by a few species from that continent. HP Pavilion dv6-2128ca CPU Fan
These species would become modified over time, but would still be related to species found on the continent, and Darwin observed that this was a common pattern. Darwin discussed ways that species could be dispersed across oceans to colonise islands, many of which he had investigated experimentally.
Chapter XII continues the discussion of biogeography. HP Pavilion dv7-3004el CPU Fan
After a brief discussion of freshwater species, it returns to oceanic islands and their peculiarities; for example on some islands roles played by mammals on continents were played by other animals such as flightless birds or reptiles. The summary of both chapters says:
I think all the grand leading facts of geographical distribution are explicable on the theory of migration (generally of the more dominant forms of life), HP Pavilion dv7-4050ev CPU Fan
together with subsequent modification and the multiplication of new forms. We can thus understand the high importance of barriers, whether of land or water, which separate our several zoological and botanical provinces. We can thus understand the localisation of sub-genera, genera, and families; and how it is that under different latitudes, for instance in South America, HP G42-367TU CPU Fan
the inhabitants of the plains and mountains, of the forests, marshes, and deserts, are in so mysterious a manner linked together by affinity, and are likewise linked to the extinct beings which formerly inhabited the same continent ... On these same principles, we can understand, as I have endeavoured to show, why oceanic islands should have few inhabitants, but of these a great number should be endemic or peculiar; HP Pavilion dv5-1172el CPU Fan
Chapter XIII starts by observing that classification depends on species being grouped together in a multilevel system of groups and sub groups based on varying degrees of resemblance. After discussing classification issues, Darwin concludes:
All the foregoing rules and aids and difficulties in classification are explained, if I do not greatly deceive myself, on the view that the natural system is founded on descent with modification; Toshiba Satellite A105-S4084 CPU Fan
that the characters which naturalists consider as showing true affinity between any two or more species, are those which have been inherited from a common parent, and, in so far, all true classification is genealogical; that community of descent is the hidden bond which naturalists have been unconsciously seeking,
Darwin discusses morphology, including the importance of homologous structures. HP Pavilion dv4-1038tx CPU Fan
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?" He notes that animals of the same class often have extremely similar embryos.HP Pavilion dv7-3060sb CPU Fan
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.
The final chapter reviews points from earlier chapters, and Darwin concludes by hoping that his theory might produce revolutionary changes in many fields of natural history. HP Pavilion dv7-6055sf CPU Fan
Although he avoids the controversial topic of human origins in the rest of the book so as not to prejudice readers against his theory, here he ventures a cautious hint that psychology would be put on a new foundation and that "Light will be thrown on the origin of man". Darwin ends with a passage that became well known and much quoted: SONY VGN-CS108D CPU Fan
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us ... DELL XPS M170 CPU Fan
Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, HP Pavilion G72-b15SV CPU Fan
from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
Darwin's aims were twofold: to show that species had not been separately created, and to show that natural selection had been the chief agent of change. He knew that his readers were already familiar with the concept of transmutation of species from Vestiges, HP G62-120ES CPU Fan
and his introduction ridicules that work as failing to provide a viable mechanism. Therefore the first four chapters lay out his case that selection in nature, caused by the struggle for existence, is analogous to the selection of variations under domestication, and that the accumulation of adaptive variations provides a scientifically testable mechanism for evolutionary speciation. HP Pavilion dv6-3034ss CPU Fan
Later chapters provide evidence that evolution has occurred, supporting the idea of branching, adaptive evolution without directly proving that selection is the mechanism. Darwin presents supporting facts drawn from many disciplines, showing that his theory could explain a myriad of observations from many fields of natural history that were inexplicable under the alternate concept that species had been individually created.[ HP Pavilion dv7-3165ef CPU Fan
The structure of Darwin's argument showed the influence of John Herschel, whose philosophy of science maintained that a mechanism could be called a vera causa (true cause) if three things could be demonstrated: its existence in nature, its ability to produce the effects of interest, and its ability to explain a wide range of observations. HP X16-1000 Series CPU Fan
The Examiner review of 3 December 1859 commented, "Much of Mr. Darwin's volume is what ordinary readers would call 'tough reading;' that is, writing which to comprehend requires concentrated attention and some preparation for the task. All, however, is by no means of this description, and many parts of the book abound in information, easy to comprehend and both instructive and entertaining." IBM ThinkPad Z61m CPU Fan
While the book was readable enough to sell, its dryness ensured that it was seen as aimed at specialist scientists and could not be dismissed as mere journalism or imaginative fiction. Unlike the still-popular Vestiges, it avoided the narrative style of the historical novel and cosmological speculation, though the closing sentence clearly hinted at cosmic progression. ACER Aspire One D250 CPU Fan
Darwin had long been immersed in the literary forms and practices of specialist science, and made effective use of his skills in structuring arguments. David Quammen has described the book as written in everyday language for a wide audience, but noted that Darwin's literary style was uneven: in some places he used convoluted sentences that are difficult to read; in other places his writing was beautiful. ACER Ferrari 4000 CPU Fan
Quammen advised that later editions were weakened by Darwin making concessions and adding details to address his critics, and recommended the first edition.James T. Costa said that because the book was an abstract produced in haste in response to Wallace's essay, it was more approachable than the big book on natural selection Darwin had been working on, HP G42-367TU CPU Fan
which would have been encumbered by scholarly footnotes and much more technical detail. He added that some parts of Origin are dense, but other parts are almost lyrical, and the case studies and observations are presented in a narrative style unusual in serious scientific books, which broadened its audience.
The book aroused international interest and a widespread debate, with no sharp line between scientific issues and ideological, social and religious implications. Toshiba Satellite L350-146 CPU Fan
Much of the initial reaction was hostile, but Darwin had to be taken seriously as a prominent and respected name in science. There was much less controversy than had greeted the 1844 publicationVestiges of Creation, which had been rejected by scientists, but had influenced a wide public readership into believing that nature and human society were governed by natural laws. HP Pavilion dv8335ea CPU Fan
The Origin of Species as a book of wide general interest became associated with ideas of social reform. Its proponents made full use of a surge in the publication of review journals, and it was given more popular attention than almost any other scientific work, though it failed to match the continuing sales of Vestiges. Dell Vostro 3400 CPU Fan
Darwin's book legitimised scientific discussion of evolutionary mechanisms, and the newly coined termDarwinism was used to cover the whole range of evolutionism, not just his own ideas. By the mid-1870s, evolutionism was triumphant.
With the exception of a brief hint in the final chapter, Darwin had avoided the subject of human evolution. APPLE MG62090V1-Q020-S99 CPU Fan
Despite this, the first review claimed it made a creed of the "men from monkeys" idea from Vestiges. Human evolution became central to the debate and was strongly argued by Huxley who featured it in his popular "working-men's lectures". Darwin did not publish his own views on this until 1871. APPLE 15" Macbook Pro Unibody CPU Fan
The naturalism of natural selection conflicted with presumptions of purpose in nature and while this could be reconciled bytheistic evolution, other mechanisms implying more progress or purpose were more acceptable. Herbert Spencer had already incorporated Lamarckism into his popular philosophy of progressive free market human society. Gateway 6020GZ CPU Fan
He popularised the termsevolution and survival of the fittest, and many thought Spencer was central to evolutionary thinking.
Scientific readers were already aware of arguments that species changed through processes that were subject to laws of nature, but the transmutational ideas of Lamarck and the vague "law of development" of Vestiges had not found scientific favour. Toshiba Satellite Pro M30-891 CPU Fan
Darwin presented natural selection as a scientifically testable mechanism while accepting that other mechanisms such as inheritance of acquired characters were possible. His strategy established that evolution through natural laws was worthy of scientific study, and by 1875, most scientists accepted that evolution occurred but few thought natural selection was significant.Toshiba Satellite Pro M30-782 CPU Fan
Darwin's scientific method was also disputed, with his proponents favouring theempiricism of John Stuart Mill's A System of Logic, while opponents held to the idealist school of William Whewell's Philosophy of the Inductive Sciences, in which investigation could begin with the intuitive truth that species were fixed objects created by design. HP Pavilion dv5-1050eo CPU Fan
Early support for Darwin's ideas came from the findings of field naturalists studying biogeography and ecology, including Joseph Dalton Hooker in 1860, and Asa Gray in 1862. Henry Walter Bates presented research in 1861 that explained insect mimicry using natural selection. Alfred Russel Wallace discussed evidence from his Malay archipelago research, including an 1864 paper with an evolutionary explanation for the Wallace line. SONY VGN-SZ220 CPU Fan
Evolution had less obvious applications to anatomy and morphology, and at first had little impact on the research of the anatomist Thomas Henry Huxley. Despite this, Huxley strongly supported Darwin on evolution; though he called for experiments to show whether natural selection could form new species, and questioned if Darwin'sgradualism was sufficient without sudden leaps to cause speciation. Dell Studio XPS 1645 CPU Fan
Huxley wanted science to be secular, without religious interference, and his article in the April 1860 Westminster Review promoted scientific naturalism over natural theology, praising Darwin for "extending the domination of Science over regions of thought into which she has, as yet, hardly penetrated" and coining the term "Darwinism" as part of his efforts to secularise and professionalise science. ACER eMachines 7230 CPU Fan
Huxley gained influence, and initiated the X Club, which used the journal Natureto promote evolution and naturalism, shaping much of late Victorian science. Later, the German morphologist Ernst Haeckel would convince Huxley that comparative anatomy and palaeontology could be used to reconstructevolutionary genealogies. DELL Latitude E4300 CPU Fan
The leading naturalist in Britain was the anatomist Richard Owen, an idealist who had shifted to the view in the 1850s that the history of life was the gradual unfolding of a divine plan. Owen's review of the Origin in the April 1860 Edinburgh Review bitterly attacked Huxley, Hooker and Darwin, but also signalled acceptance of a kind of evolution as a teleological plan in a continuous "ordained becoming"SONY Vaio VGN-A29LP CPU Fan
with new species appearing by natural birth. Others that rejected natural selection, but supported "creation by birth", included the Duke of Argyll who explained beauty in plumage by design. Since 1858, Huxley had emphasised anatomical similarities between apes and humans, contesting Owen's view that humans were a separate sub-class. HP Pavilion dv7t-6100 CTO CPU Fan
Their disagreement over human origins came to the fore at the British Association for the Advancement of Science meeting featuring the legendary 1860 Oxford evolution debate. In two years of acrimonious public dispute that Charles Kingsley satirised as the "Great Hippocampus Question" and parodied in The Water-Babies as the "great hippopotamus test", HP Pavilion dv7-3163cl CPU Fan
Huxley showed that Owen was incorrect in asserting that ape brains lacked a structure present in human brains. Others, including Charles Lyell and Alfred Russel Wallace, thought that humans shared a common ancestor with apes, but higher mental faculties could not have evolved through a purely material process. Darwin published his own explanation in the Descent of Man (1871). HP Pavilion dv7-4140ed CPU Fan
Evolutionary ideas, although not natural selection, were accepted by German biologists accustomed to ideas of homology inmorphology from Goethe's Metamorphosis of Plants and from their long tradition of comparative anatomy. Bronn's alterations in his German translation added to the misgivings of conservatives, but enthused political radicals.Compaq Presario CQ60-155ep CPU Fan
Ernst Haeckel was particularly ardent, aiming to synthesise Darwin's ideas with those of Lamarck and Goethe while still reflecting the spirit of Naturphilosophie. Their ambitious programme to reconstruct the evolutionary history of life was joined by Huxley and supported by discoveries in palaeontology. Haeckel used embryology extensively in his recapitulation theory, which embodied a progressive, HP Mini 110-3000sd CPU Fan
almost linear model of evolution. Darwin was cautious about such histories, and had already noted that von Baer's laws of embryology supported his idea of complex branching.
Asa Gray promoted and defended Origin against those American naturalists with an idealist approach, notably Louis Agassiz who viewed every species as a distinct fixed unit in the mind of the Creator, Compaq Presario CQ60-155ep CPU Fan
classifying as species what others considered merely varieties. Edward Drinker Cope and Alpheus Hyatt reconciled this view with evolutionism in a form of neo-Lamarckisminvolving recapitulation theory.
French speaking naturalists in several countries showed appreciation of the much modified French translation by Clémence Royer, but Darwin's ideas had little impact in France, where any scientists supporting evolutionary ideas opted for a form of Lamarckism. SONY Vaio VPC-EA46FM/B CPU Fan
The intelligentsia in Russia had accepted the general phenomenon of evolution for several years before Darwin had published his theory, and scientists were quick to take it into account, although the Malthusian aspects were felt to be relatively unimportant. The political economy of struggle was criticised as a British stereotype by Karl Marx and by Leo Tolstoy, Toshiba Satellite L500-1XL CPU Fan
who had the character Levin in his novel Anna Karenina voice sharp criticism of the morality of Darwin's views.
There were serious scientific objections to the process of natural selection as the key mechanism of evolution, includingKarl von Nägeli's insistence that a trivial characteristic with no adaptive advantage could not be developed by selection. Darwin conceded that these could be linked to adaptive characteristics. HP Mini 110-3000sd CPU Fan
His estimate that the age of the Earth allowed gradual evolution was disputed by William Thomson (later awarded the title Lord Kelvin), who calculated that it had cooled in less than 100 million years. Darwin accepted blending inheritance, but Fleeming Jenkin calculated that as it mixed traits, natural selection could not accumulate useful traits. Darwin tried to meet these objections in the 5th edition. HP Pavilion dv7-3162nr CPU Fan
Mivartsupported directed evolution, and compiled scientific and religious objections to natural selection. In response, Darwin made considerable changes to the sixth edition. The problems of the age of the Earth and heredity were only resolved in the 20th century.
By the mid-1870s, most scientists accepted evolution, but relegated natural selection to a minor role as they believed evolution was purposeful and progressive. HP 480481-001 CPU Fan
The range of evolutionary theories during "the eclipse of Darwinism" included forms of "saltationism" in which new species were thought to arise through "jumps" rather than gradual adaptation, forms of orthogenesis claiming that species had an inherent tendency to change in a particular direction, and forms of neo-Lamarckism in which inheritance of acquired characteristics led to progress. HP 622029-001 CPU Fan
The minority view of August Weismann, that natural selection was the only mechanism, was called neo-Darwinism. It was thought that the rediscovery of Mendelian inheritance invalidated Darwin's views.
While some, like Spencer, used analogy from natural selection as an argument against government intervention in the economy to benefit the poor, Toshiba Satellite L555-12P CPU Fan
others, including Alfred Russel Wallace, argued that action was needed to correct social and economic inequities to level the playing field before natural selection could improve humanity further. Some political commentaries, including Walter Bagehot's Physics and Politics (1872), attempted to extend the idea of natural selection to competition between nations and between human races. HP GB0507PGV1-A CPU Fan
Such ideas were incorporated into what was already an ongoing effort by some working inanthropology to provide scientific evidence for the superiority of Caucasians over non white races and justify European imperialism. Historians write that most such political and economic commentators had only a superficial understanding of Darwin's scientific theory, and were as strongly influenced by other concepts about social progress and evolution, HP Pavilion dv7-1135nr CPU Fan
such as the Lamarckian ideas of Spencer and Haeckel, as they were by Darwin's work. Darwin objected to his ideas being used to justify military aggression and unethical business practices as he believed morality was part of fitness in humans, and he opposed polygenism, the idea that human races were fundamentally distinct and did not share a recent common ancestry. Dell Latitude E6510 CPU Fan
The book produced a wide range of religious responses at a time of changing ideas and increasing secularisation. The issues raised were complex and there was a large middle ground. Developments in geology meant that there was little opposition based on a literal reading of Genesis, but defence of the argument from design and natural theology was central to debates over the book in the English-speaking world. DELL DC280005FF0 CPU Fan
Natural theology was not a unified doctrine, and while some such as Louis Agassiz were strongly opposed to the ideas in the book, others sought a reconciliation in which evolution was seen as purposeful. In the Church of England, some liberal clergymen interpreted natural selection as an instrument of God's design, with the cleric Charles Kingsley seeing it as "just as noble a conception of Deity". HP KSB0605HB CPU Fan
In the second edition of January 1860, Darwin quoted Kingsley as "a celebrated cleric", and added the phrase "by the Creator" to the closing sentence, which from then on read "life, with its several powers, having been originally breathed by the Creator into a few forms or into one". While some commentators have taken this as a concession to religion that Darwin later regretted, HP 580696-001 CPU Fan
Darwin's view at the time was of God creating life through the laws of nature, and even in the first edition there are several references to "creation".
Baden Powell praised "Mr Darwin's masterly volume [supporting] the grand principle of the self-evolving powers of nature". In America, HP Pavilion dv7-4014eo CPU Fan
Asa Gray argued that evolution is the secondary effect, or modus operandi, of the first cause, design, and published a pamphlet defending the book in terms of theistic evolution, Natural Selection is not inconsistent with Natural Theology.Theistic evolution became a popular compromise, and St. George Jackson Mivart was among those accepting evolution but attacking Darwin's naturalistic mechanism. DELL Studio 1555 CPU Fan
Eventually it was realised that supernatural intervention could not be a scientific explanation, and naturalistic mechanisms such as neo-Lamarckism were favoured over natural selection as being more compatible with purpose.Even though the book had barely hinted at human evolution, it quickly became central to the debate as mental and moral qualities were seen as spiritual aspects of the immaterial soul, HP G62-339WM CPU Fan
and it was believed that animals did not have spiritual qualities. This conflict could be reconciled by supposing there was some supernatural intervention on the path leading to humans, or viewing evolution as a purposeful and progressive ascent to mankind's position at the head of nature. While many conservative theologians accepted evolution, HP Pavilion dv5-1145ev CPU Fan
Charles Hodge argued in his 1874 critique "What is Darwinism?" that "Darwinism", defined narrowly as including rejection of design, was atheism though he accepted that Asa Gray did not reject design. Asa Gray responded that this charge misrepresented Darwin's text. By the early 20th century, four noted authors of The Fundamentals were explicitly open to the possibility that God created through HP F787 CPU Fan
evolution, but fundamentalism inspired the American creation–evolution controversy that began in the 1920s. Some conservative Roman Catholic writers and influential Jesuits opposed evolution in the late 19th and early 20th century, but other Catholic writers, starting with Mivart, pointed out that early Church Fathers had not interpreted Genesis literally in this area. HP Pavilion dv7-3155eb CPU Fan
The Vatican stated its official position in a 1950 papal encyclical, which held that evolution was not inconsistent with Catholic teaching.
Various alternative evolutionary mechanisms favoured during "the eclipse of Darwinism" became untenable as more was learned about inheritance and mutation. DELL Studio 1458 CPU Fan
The full significance of natural selection was at last accepted in the 1930s and 1940s as part of the modern evolutionary synthesis. During that synthesis biologists and statisticians, including R. A. Fisher, Sewall Wright and J.B.S. Haldane, merged Darwinian selection with a statistical understanding of Mendelian genetics. Toshiba Satellite A505-S6970 CPU Fan
Modern evolutionary theory continues to develop. Darwin's theory of evolution by natural selection, with its tree-like model of branching common descent, has become the unifying theory of the life sciences. The theory explains the diversity of living organisms and their adaptation to the environment. It makes sense of thegeologic record, biogeography, parallels in embryonic development, biological homologies, HP Pavilion dv6-3090si CPU Fan
vestigiality,cladistics, phylogenetics and other fields, with unrivalled explanatory power; it has also become essential to applied sciences such as medicine and agriculture. Despite the scientific consensus, a religion-based political controversy has developed over how evolution is taught in schools, especially in the United States. HP G60-215EM CPU Fan
Interest in Darwin's writings continues, and scholars have generated an extensive literature, the Darwin Industry, about his life and work. The text of Origin itself has been subject to much analysis including avariorum, detailing the changes made in every edition, first published in 1959, and a concordance, an exhaustive external index published in 1981. Toshiba Satellite A100-011 CPU Fan
Worldwide commemorations of the 150th anniversary of the publication of On the Origin of Species and the bicentenary of Darwin's birth were scheduled for 2009. They celebrated the ideas which "over the last 150 years have revolutionised our understanding of nature and our place within it".DELL XPS M1210 CPU Fan, HP G62-120SL CPU Fan,HP Pavilion dv6-2117eo CPU Fan,Toshiba Satellite L305D-S5950 CPU Fan
commenter cet article