Charles Darwin and Alfred Russel Wallace - their theory of evolution - malthus on population
Alfred Russel Wallace OM FRS (8 January – 7 November ) was a British naturalist, His family, like many Wallaces, claimed a connection to William Wallace, a leader of Scottish forces during the Wars of Scottish Independence in. Memes appeared in human evolution when our ancestors became capable of imitation. As Darwin () first pointed out, if you have creatures that vary, and if . the internal end of the knowledge relationship” (Plotkin , p ), .. This problem led Wallace to argue, against Darwin, that humans. Darwin and Wallace both seemed to think that small changes over time would result in new species, Alfred Wallace seems to have concentrated his efforts a.
Another attempt at securing a gentleman's education and career was made, after his father had suggested the Church, by sending him to Christ's College, Cambridge, into study theology with a view to becoming ordained as a clergyman. During his Cambridge years he did not immerse himself in Theological studies but rather fell in with a set who were keen on fox-hunting and game shooting. He also loved to collect plants, insects, and geological specimens, guided by his cousin William Darwin Fox, an entomologist.
He developed a particular interest in collecting beetles, the rarer in species the better. His autobiography quotes one particular beetle hunt in detail: Alas it ejected some intensely acrid fluid, which burnt my tongue so that I was forced to spit the beetle out, which was lost, as well as the third one".
His modest and untrained scientific inclinations were encouraged by Alan Sedgewick, a geologist and also by a botany professor, John Stevens Henslow, who was instrumental, despite heavy paternal opposition, in securing a unpaid place for Darwin as a naturalist on a long term scientific expedition that was to be made by HMS Beagle. The intended career in the church had, at no time, been explicitly abandoned but his gaining the place on the HMS Beagle meant that he took another path in life.
Alfred Russel Wallace was born near Usk, Monmouthshire now part of GwentWales as the eighth child of a family a family, where the father of the family was employed as librarian in Hertford, an English county town not too far distant from London. Wallace lost much of his remaining property through ill advised dealings in resulting in real hardship for the family - Alfred Russel Wallace, then barely into his teenage years, had to cut short his formal education late in Family contacts in the form of an older brother, William, owning a surveying business led to Wallace embarking on a career as a surveyor where a growing interest in Natural History could also be followed up, to some extent, between daily tasks.
It happened, however, that William Wallace's business fell on hard times causing Wallace to lose his place in He was now successful in gaining a position as a teacher of Surveying in the Collegiate School in Leicester where he had access to a library where there were several reliable books on Natural History.
In Wallace made the acquaintance of another young man seriously interested in Natural History named Henry Walter Bateswho although only nineteen years of age, was a well-recognised proficient in the then fashionable pursuit of beetle-collecting and who had already been able to get some scholarly work in Entomology printed in the learned journal, Zoologist. Other formative developments in his life in these times included attendance at a demonstration of mesmerism - Wallace found that he could himself reproduce the same effects as the mesmerist demonstated and, more seriously, the death of his brother, William, in February which was followed by Wallace returning to surveying and his brother, John, joining him in the business.
Wallace found his adminstrative responsibilities particularly arduous. After the failure of the business Wallace worked as a surveyor in connection with a proposed railway in the Vale of Neath. He also found time to give lectures on science and engineering at the Mechanics' Institute of Neath and to act as a curator of the Neath Philosophical and Literary Institute's museum. His interest in Natural History continued and he entered into a regular correspondence with his friend Henry Bates.
During thes times Wallace seems to have read, and to have corresponded with Henry Bates about, Charles Darwin's journal on the Voyage of the Beagle, Charles Lyell's Principles of Geology which offered to demonstrate how long-term change, in Geology in this instance, could be effected through the operation of slow, long-term processes, and an anonomously published work Vestiges of the Natural History of Creation, later known to be by Robert Chamberswhich was an early, popular, and notably controversial effort at arguing pursuasively against both Creationism and Lamarckism as full explanations of the existence of the solar system, the earth, and the diversity of species.
The latter two of these works might be thought to have almost prepared Alfred Russel Wallace's mind for an acceptance of evolutionism. Wallace had read Charles Darwin's book about the Voyage of the Beagle and his admiration for the adventures and the observations of natural phenomena that Darwin wrote about as having occured during the Beagle voyage and also those related in a book by William H. Edwards entitled A Voyage Up the River Amazon which came into Wallace's hands resulted in his suggesting to his friend Bates that they set themselves up as professional collectors of Natural History specimens to supply the needs of institutions and gentlemen naturalists.
The two young men, they were both in their early twenties, sailed for the mouth of the Amazon in April, In South America Wallace and Bates worked independently of each other with Wallace travelling and collecting samples in the Amazon basin for several years until, earlyill health led him to decide to return home to England.
His activities as a collector of Natural History specimens, and his authorship of academic papers and of his two books that were fairly well received brought him a little bit of notice in the then somewhat fashionable Natural History circles of society and, during these times he became introduced to many interested persons including one Charles Darwin. Wallace is considered to have been something of a convinced evolutionist but without seeing how such evolution might be driven.
In this paper Wallace sets out his "Law" which he claims to have discovered some ten years previously and which he has since then been subject to testing.
This possible Law being that: Shortly thereafter Wallace's paper continues: It is evidently possible that two or three distinct species may have had a common antitype, and that each of these may again have become the antitypes from which other closely allied species were created. This paper was read by Sir Charles Lyell who found its contents to suggest strongly that Species were not fixed creations of God, but were in fact naturally mutable.
As a friend of Charles Darwin, who knew that Darwin had been considering the Emergence of Species for a considerable time he subsequently urged Darwin to make efforts to complete his work on related subjects to establish academic priority for his own ideas.
I can see no more reason to doubt that these causes in a thousand generations would produce a marked effect, and adapt the form of the fox or dog to the catching of hares instead of rabbits, than that greyhounds can be improved by selection and careful breeding. Professor Owen has pointed out the numerous instances in the animal kingdom of a principle of structure prevalent throughout the vegetable kingdom, exemplified by the multiplication of organs in one animal performing the same function, and not related to each other by combination of powers for the performance of a higher function.
The Invertebrate animals, according to the Professor, afford the most numerous and striking illustration of the principles which he has generalised as the 'Law of Irrelative Repetition. The repetition of similar segments in the spinal column, and of similar elements in a vertebral segment, is analogous to the repetition of similar crystals, as the result of the polarising force in the growth of an inorganic body.
Not only does the principle of vegetative repetition prevail more and more as we descend in the scale of animal life, but the forms of the repeated parts of the skeleton approach more and more to geometrical figures; as we see, for example, in the external skeletons of the echini and star-fishes: Here, therefore, we have direct proof of the concurrence of such general all-pervading polarising force, with the adaptive or special organising force, in the development of an animal body.
Baer pointed out that the structure was 'more generalised,' in the ratio of the proximity of the individual to the starting point of its existence. In proportion as the individual is subject to the action and reaction of surrounding influences, in other words, as it advances in life, does it acquire a more specialised structure--more decided specific and individual characters [ 18 ].
Owen has shown that the more generalised structure is, in a very significant degree, a characteristic of many extinct as compared with recent animals; and it may be readily conceived that specialisation of structure would be the result of the progressive modification of any organ applied to a special purpose in the animal economy.
We have cited these attempts to elucidate the nature of the organising forces, to show the prevalent condition of the most advanced physiological minds in regard to the cause of the successive introduction of distinct species of plants and animals.
Demaillet invoked the operation of the external influences or conditions of life, with the consentaneous volitional efforts, in order to raise species in the scale, as the fish, e. Buffon called in the same agency to lower the species, by way of degeneration, as the bear, e. Lamarck added to these outward influences the effects of increased or decreased use or action of parts.
The Author of Vestiges, availing himself of the ingenious illustration of a pre-ordained exception, occurring at remote intervals, to the ordinary course, derived by Babbage from the working of his Calculating Engine, threw out the suggestion of a like rare exception in the character of the offspring of a known species, and he cites the results of embryological studies, to show how such 'monster,' either by excess or defect, by arrest or prolongation of development, might be no monster in fact, but one of the preordained exceptions in the long series of natural operations, giving rise to the introduction of a new species.
Owen has not failed to apply the more recent discoveries of Parthenogenesis to the same mysterious problem. But he resists the seduction of possibilities, and governed by the extent of actual observation, says: Wallace calls attention to the 'tremendous rate of increase in a few years from a single pair of birds producing two young ones each year, and this only four times in their life; in fifteen years such pair would have increased to nearly ten millions!
But, as a general rule, the animal population of a country is stationary, being kept down by a periodical deficiency of food and other checks. Hence the struggle for existence; and the successful result of adapted organisation and powers in a well developed variety, which Mr. Darwin generalises as 'Natural Selection,' and which Mr. Wallace [ 23 ] illustrates as follows: The superior variety would then alone remain, and on a return to favourable circumstances would rapidly increase in numbers and occupy the place of the extinct species and variety.
The variety would now have replaced the species, of which it would be a more perfectly developed and a more highly organised from. Applying this principle to the two hundred mammalian species of which he had given a history in his great work, he believed himself able to reduce them to a very small number of primitive stocks or families [ 26 ].
Of these he enumerates fifteen: Such evidences have been mainly operative with the later adopters and diffusers of Buffon's principle in the reduction of the number of primitive sources of existing species, and the contraction of the sphere of direct creative acts. Thus Lamarck [ 29 ] reduces the primordial forms or prototypes of animals to two, viz. The class of fishes, deriving its several forms from combinations of transmuted squids and crabs, then proceeded through the well-defined vertebrate pattern up to man.
With a philosophic consistency, wanting in his latest follower, Lamarck sums up: Darwin, availing himself of the more exact ideas of the affinities and relationships of animal groups obtained by subsequent induction, says: Darwin logically admits, 'would lead us one stop further, namely, to the belief that all animals and plants have descended from some one prototype;' [ 32 ] and, summing up the conditions which all living things have in common, this writer infers from that analogy, 'that probably all the organic beings which have ever lived on this earth, have descended from some one primordial form, into which life was first breathed.
Darwin formally recognises, in the so-limited beginning, a direct creative act, something like that supernatural or miraculous one which, in the preceding page, he defines, as 'certain elemental atoms which have been commanded suddenly to flash into living tissues.
He leaves us to imagine our globe, void, but so advanced as to be under the conditions which render life possible; and he then restricts the Divine power of breathing life into organic form to its minimum of direct operation. All subsequent organisms henceforward result from properties imparted to the organic elements at the moment of their creation, pre-adapting them to the infinity of complications and their morphological results, which now try to the utmost the naturalist's faculties to comprehend and classify.
And we admit, with Buckland, that such an aboriginal constitution, 'far from superseding an intelligent agent, would only exalt our conceptions of the consummate skill and power, that could comprehend such an infinity of future uses, under future systems, in the original groundwork of his creation.
Literal scripturalism in the time of Lactantius, opposed and reviled the demonstrations of the shape of the earth; in the time of Galileo it reviled and persecuted the demonstrations of the movements of the earth; in the time of Dean Cockburn of York, it anathematised the demonstrations of the antiquity of the earth; and the eminent geologist who then personified the alleged anti-scriptural heresy, has been hardly less emphatic than his theological assault, in his denunciations of some of the upholders of the 'becoming and succession of species by natural law,' or by 'a continuously operating creative force.
The author of the volume 'On the Origin of Species,' starts from a single supernaturally created form. He does not define it; it may have been beyond his power of conception. It is, however, eminently plastic, is modified by the influence of external circumstances, and propagates such modifications by generation. Where such modified descendant find favourable conditions of existence, there they thrive; where otherwise they perish.
In the first state of things, the result is so analogous to that which man brings about, in establishing a breed of domestic animals from a selected stock, that it suggested the phrase of 'Natural Selection;' and we are appealed to, or at least 'the young and rising naturalists with plastic minds' [ 35 ], are adjured, to believe that the reciprocal influences so defined have operated, through divergence of character and extinction, on the descendants of a common parent, so as to produce all the organic beings that live, or have ever lived, on our planet.
Now we may suppose that the primeval prototype began by producing, in the legal generative way, creatures like itself, or so slightly affected by external influences, as at first to be scarcely distinguishable from their parent. When, as the progeny multiplied and diverged, they came more and more under the influence of 'Natural Selection' so, through countless ages of this law's operation, they finally rose to man. But, we may ask, could any of the prototype's descendants utterly escape the surrounding influences?
To us such immunity, in the illimitable period during which the hypothesis of Natural Selection requires it to have operated, is inconceivable. No living being, therefore, can now manifest the mysterious primeval form to which Darwin restricts the direct creative act; and we may presume that this inevitable consequence of his hypothesis, became to him an insuperable bar to the definition of that form.
But do the facts of actual organic nature square with the Darwinian hypothesis? Are all the recognised organic forms of the present date, so differentiated, so complex, so superior to conceivable primordial simplicity of form and structure, as to testify to the effects of Natural Selection continuously operating through untold time? The most numerous living beings now on the globe are precisely those which offer such a simplicity of form and structure, as best agrees, and we take leave to affirm can only agree, with that ideal prototype from which, by any hypothesis of natural law, the series of vegetable and animal life might have diverged.
If by the patient and honest study and comparison of plants and animals, under their manifold diversities of matured form, and under every step of development by which such form is attained, any idea may be gained of a hypothetical primitive organism,--if its nature is not to be left wholly to the unregulated fancies of dreamy speculation--we should say that the form and condition of life which are common, at one period of existence, to every known kind and grade of organism, would be the only conceivable form and condition of the one primordial being from which 'Natural Selection' infers that all the organisms which have ever lived on this earth have descended.
Now the form in question is the nucleated cell, having the powers of receiving nutritive matter from without, of assimilating such nutriment, and of propagating its kind by spontaneous fission.
Why does Charles Darwin eclipse Alfred Russel Wallace? - BBC News
These powers are called 'vital,' because as long as they are continued the organism is said to live. The most numerous and most widely diffused of living beings present this primitive grade of structure and vital force, which grade is inferior to that of the truly definable 'plant' or 'animal,' but is a grade represented and passed through by the term of every, even the highest, class of animals, in the course of embryonic development.
The next stages of differentiated or advanced organisation are defined as follows in Professor Owen's last publication: The prevalence of the essential first step in the production of all higher organisms, viz. The single-celled organisms, such as many of the so-called animalcules of infusions, which are at a stage of organisation too low for a definite transfer to either the vegetable or animal kingdoms, offer a field of observation and experiment which may yet issue in giving us a clearer insight into the development of the organic living cell.
This, at least, may be affirmed, that the inductive groundwork of his opponents is by no means such as can justify any dogmatic negation of Heterogeny as applicable to the simplest Protozoa. On the basis, therefore, of analogical probability, it may be inferred: The monad that by 'natural selection' has ultimately become man, dates from the farthest point in the remote past, upon which our feigners of developmental hypotheses can draw with unlimited credit: Accordingly we find that every grade of structure, from the lowest to the highest, from the most simple to the most complex, is now in being,--a result which it is impossible to reconcile with the Darwinian hypothesis of the one and once only created primordial form, the parent of all subsequent living things.
It is now, therefore, generally inferred that the extinction of species, prior to man's existence, has been due to ordinary causes--ordinary in the sense of agreement with the great laws of never-ending mutation of geographical and climatal conditions on the earth's surface. The individuals of species least adapted to bear such influences and incapable of modifying their organisation in harmony therewith, have perished.
Extinction, therefore, on this hypothesis, is due to the want of self-adjusting, self-modifying power in the individuals of the species. In a joint paper on the tendency of varieties to form species by natural means of selection [ 39 ]one of the authors writes: In the struggle it would have a better chance of surviving, and those of its offspring which inherited the variation would also have a better chance.
Let this work go on for a thousand generations, and who will pretend to affirm,' asks Mr. Darwin, 'that a new species might not be the result? Now this, we take leave to say, is no very profound or recondite surmise; it is just one of those obvious possibilities that might float through the imagination of any speculative naturalist; only, the sober searcher after truth would prefer a blameless silence to sending the proposition forth as explanatory of the origin of species, without its inductive formation.
In the degeneration-theory of Buffon, man is one of the primitive types,--the created apes and monkeys are derivatives. He might have illustrated it as follows: Suppose also that a tiger or like destructive carnivore should swim over and settle in the island, which happened to be destitute of flints for weapons. The human organisation being slightly plastic, those individual with the longest and strongest arms, and with the most prehensile use of the great toe, let the difference be every so small, would be slightly favoured, would survive during the time of the year when food was scarcest on the ground, but ripe and ready on certain trees; they would also rear more young which would tend to inherit these slight peculiarities.
The best climbers would escape the tigers, the worst would be rigidly destroyed. Buffon would have seen no more reason to doubt that these causes, in a thousand generations, would produce a marked effect, and adapt the form of the wild man to obtain fruits rather than grains, than Darwin now believes that man can be improved by selection and careful interbreeding into a higher, more heroic, more angelic form!
The advocate of Buffon's hypothesis might point out that it is on islands, as Borneo and Sumatra, for example, where the orang-utan--the obvious result of such 'degradation by natural selection'--is exclusively found.
And is it not there also, and in some other islands of the Malayan Archipelago, where the next step in the scale of 'degeneration' is exhibited in the still longer-armed Ungkas and other tail-less Hylobates?
And though we call them 'tail-less' yet they have the 'os coccygis;' and this being a terminal appendage of stunted vertebrates, offers the very condition for the manifestation of an occasional developmental variety.
If cats, after accidental mutilation or malformation, can propagate a tail-less breed, why may not apes produce a tailed variety, and by natural selection in a long course of ages, degenerate into endless incipient species of 'baboons and monkeys'? Darwin, it may be said, repudiates the coarse transmutational conditions and operations of Buffon and Lamarck; or, if there be any parallel between his and Buffon's illustration of the changing of species, at all events such parallels must run in opposite directions.
Darwin starts from a single created prototype, from which it is difficult to conceive he can mean any other course of organic progress than an ascensive one. But of this, in the absence of a definition of the starting point, we cannot be perfectly sure.
Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.
Darwin, when naturalist on board H. Beagle, 'to throw some light on the origin of species. Darwin's views of animated nature. We look, however, in vain for any instance of hypothetical transmutation in Lamarck so gross as the one above cited; we must descend to older illustrators of the favourite idea, to find an equivalent case of the bear in pursuit of water-insects, and we find one in the following: Il se fit encore d'autres petits changemens dans leur figure.
- Why does Charles Darwin eclipse Alfred Russel Wallace?
- Darwin on the Origin of Species
- Alfred Russel Wallace
Once their fins were no longer immersed in the waters of the sea, they cracked and became deformed by drying out. While they found in the reeds and vegetation into which they had fallen some food to sustain themselves, the tubes of their fins separated from each other, grew longer and became covered with barbs; or, to speak more precisely, the membranes which had previously held them together underwent a change.
The barb formed of these warped layers itself grew longer; the skin of these animals very gradually became covered with a down of the same colour as the skin, and this down grew. The small fins which they had under their belly, which like their large fins had assisted them to move in the sea, became feet, and served for their movement on the land.
There were still other small changes in their shape. The ship was to leave in four weeks on an expedition to chart the coastline of South America.
Alas, poor Wallace
As FitzRoy had intended, Darwin spent most of that time on land investigating geology and making natural history collections, while HMS Beagle surveyed and charted coasts. Most of his zoology notes are about marine invertebrates, starting with plankton collected in a calm spell. FitzRoy had given him the first volume of Charles Lyell 's Principles of Geology, which set out uniformitarian concepts of land slowly rising or falling over immense periods, [II] and Darwin saw things Lyell's way, theorising and thinking of writing a book on geology.
He identified the little-known Megatherium by a tooth and its association with bony armour, which had at first seemed to him to be like a giant version of the armour on local armadillos. The finds brought great interest when they reached England. He read Lyell's second volume and accepted its view of "centres of creation" of species, but his discoveries and theorising challenged Lyell's ideas of smooth continuity and of extinction of species. Three Fuegians on board had been seized during the first Beagle voyagethen during a year in England were educated as missionaries.
Darwin found them friendly and civilised, yet at Tierra del Fuego he met "miserable, degraded savages", as different as wild from domesticated animals. Unlike his scientist friends, he now thought there was no unbridgeable gap between humans and animals.
The Fuegian they had named Jemmy Button lived like the other natives, had a wife, and had no wish to return to England. High in the Andes he saw seashells, and several fossil trees that had grown on a sand beach. He theorised that as the land rose, oceanic islands sank, and coral reefs round them grew to form atolls. He heard that slight variations in the shape of tortoise shells showed which island they came from, but failed to collect them, even after eating tortoises taken on board as food.
Inception of Darwin's theory While still a young man, Charles Darwin joined the scientific elite. When the ship reached Falmouth, Cornwallon 2 OctoberDarwin was already a celebrity in scientific circles as in December Henslow had fostered his former pupil's reputation by giving selected naturalists a pamphlet of Darwin's geological letters.
Zoologists had a huge backlog of work, and there was a danger of specimens just being left in storage. Owen's surprising results included other gigantic extinct ground sloths as well as the Megatheriuma near complete skeleton of the unknown Scelidotherium and a hippopotamus -sized rodent -like skull named Toxodon resembling a giant capybara. The armour fragments were actually from Glyptodona huge armadillo-like creature as Darwin had initially thought.
On the same day, he presented his mammal and bird specimens to the Zoological Society. The ornithologist John Gould soon announced that the Galapagos birds that Darwin had thought a mixture of blackbirds" gros-beaks " and fincheswere, in fact, twelve separate species of finches. On 17 February, Darwin was elected to the Council of the Geological Society, and Lyell's presidential address presented Owen's findings on Darwin's fossils, stressing geographical continuity of species as supporting his uniformitarian ideas.
Darwin stayed with his freethinking brother Erasmuspart of this Whig circle and a close friend of the writer Harriet Martineauwho promoted Malthusianism underlying the controversial Whig Poor Law reforms to stop welfare from causing overpopulation and more poverty. As a Unitarian, she welcomed the radical implications of transmutation of speciespromoted by Grant and younger surgeons influenced by Geoffroy.
Transmutation was anathema to Anglicans defending social order,  but reputable scientists openly discussed the subject and there was wide interest in John Herschel 's letter praising Lyell's approach as a way to find a natural cause of the origin of new species. Darwin had not labelled the finches by island, but from the notes of others on the ship, including FitzRoy, he allocated species to islands.
By mid-March, Darwin was speculating in his Red Notebook on the possibility that "one species does change into another" to explain the geographical distribution of living species such as the rheas, and extinct ones such as the strange Macraucheniawhich resembled a giant guanaco. He sketched branching descent, then a genealogical branching of a single evolutionary treein which "It is absurd to talk of one animal being higher than another", discarding Lamarck's independent lineages progressing to higher forms.
Darwin on the Origin of Species – The Friends of Charles Darwin
Charles Darwin's health While developing this intensive study of transmutationDarwin became mired in more work. On 20 September he had "an uncomfortable palpitation of the heart", so his doctors urged him to "knock off all work" and live in the country for a few weeks.
After visiting Shrewsbury he joined his Wedgwood relatives at Maer HallStaffordshire, but found them too eager for tales of his travels to give him much rest. His charming, intelligent, and cultured cousin Emma Wedgwoodnine months older than Darwin, was nursing his invalid aunt.