s quarterly 106 ( 1 ) : 121. wallace ' s first essay on the origin of the colour sense was published simultaneously with, but independently of, gladstone ' s paper. he had presented a possible evolutionary route for animal colour vision, starting with perception of degrees of brightness, ending with perception of colours according to wave length. in his view, green and blue would have been the first colours to which the eye became specially adapted, in accord with their universal presence in foliage and sky, as well as their soothing influence. reds, yellows and violets would follow, as present in small amounts, offering great contrast, and useful to animals hunting for food and mates. this essay was revised and republished a year later, with specific response to gladstone ( and through him, to magnus and geiger ). ' these curious facts ' wrote wallace, with regard to gladstone ' s homeric data, ' can not, however, be held to prove so recent an origin for colour - sensations as they would at first sight appear to do '. he pictured brightly coloured structures as having evolved in response to an already present and well - developed ability of animals, especially birds, to see colour, long before the arrival of man. wallace concluded that ' man ' s perception of colour in the time of homer was little if any inferior to what it is now... owing to a variety of causes, no precise nomenclature of colours had become established... - - elizabeth henry bellmer, 1 january 1999. annals of science 56 ( 1 ) : 38. as the new century ripened and imperialist rivalries increased, wallace became convinced that a vast civilizational crisis was at hand and that the very survival of the human species demanded the rapid overthrow of capitalism. a few months before his death in 1913, he wrote ( the revolt of democracy ), " there must be no further compromise, no mere talking. to allow the present state of things to continue is a crime against humanity. " how ironic to recall his warnings today when billionaire arsonists have set almost the entirety of wallace ' s malay archipelago ablaze with their greed... - - mike davis, march 1998. capitalism, nature, socialism 9 ( 1 ) : 77. wallace ' s major contribution to the literature of reform is his corrosive criticism of nineteenth - century society, through which he offered a human vision of social reformation. he advocated recognizing racial equality, nationalizing land, giving women equal opportunity for education and employment, decreasing military expenditure, and saving the environment. his friend james


are sexually dimorphic in plumage throughout the year. also, it has not yet been proven that maintaining a colourful and bright plumage is costly, nor that it is a handicap for survival... - - concha mateos & juan carranza, november 1997. animal behaviour 54 ( 5 ) : 1211. the approach taken by gregorius for modelling and analyzing the population genetic basis of wallace ' s theory of speciation will be extended to allow analysis of the opposite case, where speciation is prevented by the reinforcement of genetic coherence. in this approach, a mutant gene modifies the current mating preferences without implying any advantage or disadvantage in fitness ( including mating success ). the latter assumption is indispensable in order to avoid confusion of the secondary effects of mating systems on fitness with their primary recombinational effects. it also reduces the analytical problems resulting from having to disentangle effects of fitness and mating preference on the evolution of mating behaviour... - - wilfried steiner & hans - rolf gregorius, november 1997. biosystems 43 ( 2 ) : 139. in 1881 wallace took the lead. he formed the land nationalization society on his own lines, with himself as president. in land nationalization ( 1882 ) he laid out his program. the state was to assume title to all land. to meet a conservative debating ploy, he would compensate present landowners. however, he ingeniously minimized the amount in a manner that tells us he knew the nuts and bolts of his subject. compensation was to be an annuity limited to the duration of lives in being. it was to be based only on the net income actually being derived from the land before nationalization - - i. e. not from the highest and best use, and not from future higher uses. all men and women ( wallace, like mill, was also a feminist ) could bid to lease parcels from the state for actual use. in the socio - biological terms in which he thought, this would consummate the natural relation of man to nature. it would also let men alternate between industry and agriculture as wallace, a loving gardener, himself did. wallace ' s land nationalization was individualist, not collectivist. individual lessees were to have secure tenure, and tenant - rights to improvements. rents to the state would be used, not to engross the state, but to obviate taxes. these rents would be based on the assessed " inherent value " of land, dependent only on natural and social conditions.


- rights to improvements. rents to the state would be used, not to engross the state, but to obviate taxes. these rents would be based on the assessed " inherent value " of land, dependent only on natural and social conditions. as a surveyor and a biogeographer, wallace readily distinguished " inherent value " from man ' s improvements to land, which he saw as transitory. tax assessors in most american states and other former english colonies distinguish land and improvements routinely today, and many did then, too, although in england itself the concept was somewhat novel... - - mason gaffney, october 1997. american journal of economics & sociology 56 ( 4 : ) : 613. wallace, on the other hand, explained evolution not in terms of competitive struggles between species and the environment, but in terms of the governor that regulates the speed of a steam engine by maintaining constancy in the angular velocity of a flywheel. as bateson puts it, building on wallace ' s idea, the job of evolution is to maintain the constancy of something - - specifically, the survival of the entire system comprised of all species and the environment. darwin, according to bateson, focused on the wrong subject - - the individual species - - when in fact the real subject of evolution is the species plus environment. in fact, the species and the environment co - evolve, to use a term that is popular among management writers today. moreover, if you add the remarkable findings reached in the past thirty years by biologist lynn margulis, this process of co - evolution sustains the total system through cooperative symbiotic relationships, not competitive knock - outs... - - h. thomas johnson, 11 october 1997. keynote presentation, the deming institute fall 1997 meeting, washington, d. c. perhaps the effect of wallace ' s line most relevant to us is its possible role in a decisive step of human evolution. paleontologists tend to stress africa as the cradle of humanity, to view cro - magnon europe as the site where late ice age human culture flowered, and to neglect australia as a remote outpost occupied by supposedly primitive aborigines. human behavior took a great leap forward sometime between 100, 000 years ago, where there were still no signs of art or complex tools anywhere in the world, and the period around 40, 000 to 30, 000 years ago, when great art and complex tools began to abound in europe. paleontologists usually assume that this development began among


still no signs of art or complex tools anywhere in the world, and the period around 40, 000 to 30, 000 years ago, when great art and complex tools began to abound in europe. paleontologists usually assume that this development began among humans in africa or the mideast, then spread to europe and finally ( in diluted form ) to our poorer cousins in aboriginal australia. but anatomically modern humans appeared in australia before they did in europe - - probably by 60, 000 years ago and possibly even earlier. to reach australia, the protohumans who had reached asia from africa around one million years ago ( as attested by the famous java man fossils ) had to cross a dozen straits separating australia from asia.... each next strait would have been a stimulus to improve our nascent watercraft technology ; each new island, a stimulus to adapt to a new environment and to invent new technologies ; each island ' s untapped rich resources, the basis for a new human population explosion... - - jared m. diamond, august 1997. discover 18 ( 8 ) : 83. wallace ' s writings of this period make free use of the contrast between ' savage ' and ' civilized ', he talks often of ' higher ' and ' lower ' races, and was clearly committed to a notion of long - run progressive change in organic evolution and in human history. yet there is no easy or simple mapping of the higher and lower, civilized and savage onto the progressive evolutionary narrative. social, moral and intellectual progress are differentiated from one another, and lack of harmony between them can be catastrophic in its consequences. the hierarchical ordering ' higher ' and ' lower ' is sometimes used by wallace to refer to inherited differences between peoples, but is also sometimes used to denote levels of civilization, and to do so in ways which do not carry any obvious value connotation. the word ' civilization ' carries a negative as often as a positive valuation in wallace ' s writing. whilst the civilized nations remain in a state of social and moral ' barbarism ', uncivilized savages approach a ' perfect social state '... - - ted benton, spring 1997. studies in travel writing no. 1 : 109 - 110.... it is here that we encounter the central intellectual and moral tension in wallace ' s thought, a tension which was to bring about a growing gulf between his and darwin ' s views on human origins and nature and which may, indeed, go some way towards explaining wallace ' s later involvement


the central intellectual and moral tension in wallace ' s thought, a tension which was to bring about a growing gulf between his and darwin ' s views on human origins and nature and which may, indeed, go some way towards explaining wallace ' s later involvement in spiritualist activities. wallace ' s radical political philosophy and his capacity to admire and respect the achievements, customs and social solidarity of the indigenous peoples of the amazon and the malay archipelago were increasingly at odds with his version of evolutionary naturalism... - - ted benton, spring 1997. studies in travel writing no. 1 : 110. it is not just darwin ' s opponents who regard the analogy as evidence against the causal efficacy of selection. a. r. wallace, the co - discoverer of natural selection, addresses the analogy in his opening comments of the darwin - wallace paper of 1858. " one of the strongest arguments which have been adduced to prove the original and permanent distinctness of species is, that varieties produced in a state of domesticity are more or less unstable, and often have a tendency, if left to themselves, to return to the normal form of the parent species ; and this instability is considered to be a distinctive peculiarity of all varieties. " for wallace, modification by artificial selection is limited and temporary, and therefore causally inefficacious in the production of new species. if natural and artificial selection were truly similar, then the analogy suggests that natural selection is incapable of forming new species. consequently, wallace argues against the analogy by emphasizing the differences between domestic breeding and nature. " it will be observed that this argument rests entirely on the assumption, that varieties occurring in a state of nature are in all respects analogous to or even identical with those of domestic animals... but it is the object of the present paper to show that this assumption is altogether false " ( emphasis added ). wallace ' s vow to argue against the analogy is inexplicable unless he has embraced the view that artificial selection is inefficacious in the formation of new species. surely darwin was aware of wallace ' s views, expressed so forcefully in the darwin - wallace paper, as he wrote the origin... - - richard a. richards, march 1997. studies in history and philosophy of science 28 ( 1 ) : 76 - 77.... darwin recognized some important distinction between domestic and natural varieties, and happily agrees with wallace on the distinction. wallace, in the preface to his darwinism, likewise emphasizes his agreement with darwin, describing his views as


) : 76 - 77.... darwin recognized some important distinction between domestic and natural varieties, and happily agrees with wallace on the distinction. wallace, in the preface to his darwinism, likewise emphasizes his agreement with darwin, describing his views as complementary. " i have endeavoured, by means of a series of diagrams, to exhibit to the eye the actual variations as they are found to exist in a sufficient number of species... it will be found that, throughout the work, i have frequently to appeal to these diagrams and the facts they illustrate, just as darwin was accustomed to appeal to the facts of variation among dogs and pigeons " ( emphasis added ). wallace certainly seems to regard himself as doing something very similar to what darwin is doing. that would be surprising if he had thought darwin to be making an analogical argument - - given his earlier rejection of the argument. wallace argues against the analogical argument by emphasizing the negative analogy between domestic breeding and nature. unlike natural selection, artificial selection does not maintain fitness. consequently, domestic varieties are unfit. wallace makes this point in the 1858 darwin - wallace paper... - - richard a. richards, march 1997. studies in history and philosophy of science 28 ( 1 ) : 81. one reference point, however, must be marked if wallace ' s future path - - to the malthusian moment and beyond - - is to be mapped. he embarked on a scientific career less a naturalist than a surveyor, less a biologist than a biogeographer, less an evolutionist than an ethnographer. for seven formative years his job had been prescriptive economic geography. parish upon parish, field upon field, he had set limits to human livelihoods, marking boundaries, drawing lines. in later years he would become an exemplary naturalist, but always boundaries and borders, habits and habitats, concerned him. once he even likened the " system of nature " to a " dissected map, " the pieces of which could be assembled in a " mosaic. " the picture is of a crowded tithe map, where field presses on field, niche upon niche, until " all gaps have been filled ". such was a surveyor ' s view of evolution... - - james moore, 1997. in bernard lightman, ed., victorian science in context ( university of chicago press ) : 304. to validate his inclusion of plants formerly excluded from bedded - out gardens, robinson turned to the writings of the late nineteenth - century naturalist alfred russel wallace. wallace


ed., victorian science in context ( university of chicago press ) : 304. to validate his inclusion of plants formerly excluded from bedded - out gardens, robinson turned to the writings of the late nineteenth - century naturalist alfred russel wallace. wallace collaborated with darwin on his theory of evolution and published his own contribution to the theory of natural selection in 1870. robinson was intrigued by wallace ' s 1869 account of his extensive travels in the amazon region and the malay archipelago, especially wallace ' s statement that " during the twelve years spent amidst tropical vegetation, i have nothing comparable to the effect produced on our landscapes by gorse, broom, heather, wild hyacinths, hawthorn, and buttercups. " wallace ' s nationalistic preference for english scenery reportedly led robinson to plant such flowers as asters and heather, formerly considered too coarse for fashionable gardens... - - anne l. helmreich, 1997, in nature and ideology ; natural garden design in the twentieth century ( dumbarton oaks research library and collection ). the principles regarding relations between organisms and their environment set forth by wallace clearly informed robinson ' s gardening practices. in an early essay, " on the law which has regulated the introduction of new species, " wallace first developed his theory governing the distribution of organisms. his fourth stipulation - - that " in countries of a similar climate, but separated by a wide sea of lofty mountains, the families, genera, and species of the one are often represented by closely allied families, genera and species peculiar to the other " - - underlies robinson ' s theory that plants from climates similar to england ' s could be naturalized in the wild garden... - - anne l. helmreich, 1997, in nature and ideology ; natural garden design in the twentieth century ( dumbarton oaks research library and collection ). it is evident that conrad read and assimilated wallace ' s observations of the malay natural environment. wallace as anthropologist seems to have had an equivalent influence. in terms of religious practices, wallace describes how ' the old juragan repeated some prayers ' just before one of his more successful voyages ; on the patna voyage, the leading arab recites a prayer in similar fashion as they cast off. in the rescue, lingard ' s dead lacar is ' wrapped up decently in a white sheet, according to mohammedan usage ', in a way highly reminiscent of wallace ' s response to the death of one of his malay men : ' as my men were all mohammedans, i let


in selfings, whereas their continental sisters as well as the herbaceous island inhabitant e. bonnetii were preferentially inbreeding... - - uta - regina bohle, hartmut h. hilger & william f. martin, october 1996. proceedings of the national academy of sciences of the united states of america 93 ( 21 ) : 11744.... if outbreeding is the primary selective factor in island colonization, pollination pressure will subsequently favor rare, large, conspicuous inflorescences among outbreeders and, as a consequence, select perennial ( and therefore woody ) habits capable of producing them, in agreement with wallace ' s salient arguments. under this view, diversity of contemporary woody echium forms reflects a multiplicity of selectable developmental pathways toward longevity, rather than selection for specifically environment - adapted variants of such woody perennial habits as schematically depicted in fig. 3. in other words, insular woodiness in echium might simply betray " survival of the founders, " and many differences between perennial woody habits could be nonadaptive... - - uta - regina bohle, hartmut h. hilger & william f. martin, october 1996. proceedings of the national academy of sciences of the united states of america 93 ( 21 ) : 11744 - 11745. alfred russel wallace foreshadowed much of the current thinking on adaptive mate choice. to wallace colour was merely a correlate of ' vigour ', by which he implied health. a female should choose a mate adaptively by picking the most vigorous male, and it would just so happen that he would also be the most colourful. we too found colour to correlate with a variable, plasma proteins, that may be indicative of vigour. in addition, female kestrels in our colony in mate choice experiments have consistently preferred males with high display rates ( vigour? ), irrespective of the degree of genetic relatedness or experimentally induced parasite infection... - - gary r. bortolotti et al., september 1996. proceedings of the royal society of london b 263 : 1175.... the hypothesis that sexual dichromatism was nonfunctional and incidental to inherent ' physiological ' differences between the sexes was proposed by alfred russel wallace. wallace ( 1895 ) recognized that whereas males of many birds are more brightly coloured than their mates, the degree of dimorphism varied


##functional and incidental to inherent ' physiological ' differences between the sexes was proposed by alfred russel wallace. wallace ( 1895 ) recognized that whereas males of many birds are more brightly coloured than their mates, the degree of dimorphism varied greatly, with the most common case being for males ' to have the same general hue as the females, but deeper and more intensified '. although it may be difficult to discount the role of sexual selection for extreme cases, such as house finches, the common, subtle patterns of colour variation between the sexes may be more difficult to explain except as non - functional consequences of other biochemical processes. if such processes are fundamental to avian physiology, it may explain why sexual dichromatism is so common in birds, and why reds, yellows and oranges are so pervasive... - - gary r. bortolotti et al., september 1996. proceedings of the royal society of london b 263 : 1175. a final argument, " an additional argument dependent on the theory of evolution, " was added to the 1904 edition of wallace ' s book. especially interesting because wallace was so closely involved with the evolution arguments of his day, it is independent of the three connected scientific arguments and may be seen as another aspect leading to the same conclusion. wallace argued that since humanity is the result of a long chain of modifications in organic life, since these modifications occur only under certain circumstances, and since the chances of the same conditions and modifications occurring elsewhere in the universe were very small, the chances of beings in human form existing on other planets was very small. moreover, since no other animal on earth, despite the great variety of diversity of forms, approaches the intelligent or moral nature of humanity, wallace concluded that intelligence in any other form was also highly improbable... - - steven j. dick, 1996. in his the biological universe : the twentieth - century extraterrestrial life debate and the limits of science ( cambridge university press ) : 48 - 49.... in conjunction with barrow and tipler ' s use of the anthropic principle, at the end of the century one could therefore choose from the full spectrum of possibilities in the context of the extra - terrestrial life debate : a positive argument, a negative argument, and the extraterrestrially neutral argument from design. but it is remarkable that just when anthropocentrism seemed irretrievably banished from the repertoire of reputable worldviews,


positive argument, a negative argument, and the extraterrestrially neutral argument from design. but it is remarkable that just when anthropocentrism seemed irretrievably banished from the repertoire of reputable worldviews, it returned in a more sophisticated but remarkably similar form to that of a. r. wallace, who in arguing against the plurality of worlds at the beginning of the century concluded that " the supreme end and purpose of this vast universe was the production and development of the living soul in the perishable body of man. "... - - steven j. dick, 1996. in his the biological universe : the twentieth - century extraterrestrial life debate and the limits of science ( cambridge university press ) : 535.... male - male competition was obvious to those who watched animals behaving in the field, and it coincided with the victorian notion of how animals should behave, thus never becoming controversial. female choice, on the other hand, was far from obvious in the field, and darwin ' s contemporary, a. r. wallace ( 1891 ), in particular, was unconvinced by it. he felt that the power of discrimination by females was too weak to distinguish subtle differences between males, and he also doubted whether female choice could be sufficiently constant over time to select for male attributes. as geddes and thompson ( 1889 ) put it, consistency of female taste was " scarcely verifiable in human experience. " female choice continued to be contentious until relatively recently, and although there is now abundant evidence that females often choose their partners, the way that female choice has evolved still remains a controversial area of sexual selection theory... - - t. r. birkhead, 1996. current topics in developmental biology 33 : 104. the colors of the amazon brought wallace to investigate the sediment and substrata. he found the " almost perfect flatness " of the amazon valley its single most striking geological fact. no mountains or even slightly elevated plateaus rise from the plain until you reach the abrupt peaks of the andes. wallace ' s impression was that " here we see the last stage of a process that has been going on, during the whole period of the elevation of the andes " - - the gradual filling in of what was once the granite bottom of the sea with sediment brought down by rivers from the andes mountains... - - jonathan maslow, 1996. in his footsteps in the jungle : adventures in the scientific exploration of the american trop


filling in of what was once the granite bottom of the sea with sediment brought down by rivers from the andes mountains... - - jonathan maslow, 1996. in his footsteps in the jungle : adventures in the scientific exploration of the american tropics ( ivan r. dee ) : 99 - 100. in 1873, alfred russel wallace posed a fundamental, and as yet unresolved, biogeographic puzzle : why should the tropics contain a disproportionately large amount of the earth ' s biodiversity? wallace ( 1873 ) suggested that the explanation for latitudinal variation of the diversity of plant species was directly related to climate. wallace ( 1873 ) wrote " as we approach towards regions of polar cold and desert aridity the variety of groups and species [ of plants ] regularly diminishes ; more and more are unable to sustain the extreme climatical conditions ". however, in the case of animal distributions, wallace ( 1873 ) believed that climatic change associated with glaciation was responsible for the impoverishment of the temperate faunas. in modern terms, wallace proposed an ' equilibrium ' hypothesis for vegetation, and an ' historical ' hypothesis for faunal patterns. in the latter half of this century, these two schools of thought have diverged and undergone substantial specialisation, although no consensus has emerged... - - d. m. j. s. bowman, 1996. australian journal of botany 44 ( 5 ) : 571. borrowing a line from samuel taylor coleridge ' s " rime of the ancient mariner, " there is " nor any drop to drink " anywhere today on the surface of mars. not so clear is whether there has ever been water, water everywhere. as was first demonstrated by alfred wallace ( who concurrently with, but independently of, charles darwin proposed the idea of evolution by natural selection ), the lifetime for liquid water under present martian atmospheric conditions is measured in minutes. the former existence of martian rivers or seas would then imply that the planet had a warmer, more earth - like climate in its geologic past. interest in martian water also stems from the fact that we, like that famous canal enthusiast percival lowell, cannot envision any form of life existing without it. the red planet appears lifeless now, but evidence for a warmer, wetter planet in the past might make a search for martian fossils plausible... - - harry y. mcsween jr., december 1995. sky & telescope 90 ( 6 ) : 18.... the nature of


a warmer, wetter planet in the past might make a search for martian fossils plausible... - - harry y. mcsween jr., december 1995. sky & telescope 90 ( 6 ) : 18.... the nature of information conveyed by secondary sexual traits in mate selection has been hotly debated. darwin ( 1871 ) believed that mate choice was solely based on arbitrarily chosen features that were aesthetically appealing to the members of opposite sex, although such chosen features did not confer any survival advantage to the animal. wallace ( 1889 ), on the other hand, argued that natural selection would not allow the selection of merely ornamental features " unless the most ornamental always coincide with the ' fittest ' in every other respect ". the modern interpretation of the utilitarian view of wallace, or the so - called good gene hypothesis, has commonly been invoked to explain human mate selection. briefly, it is proposed that women, as a rule, can assess the " mate quality " of a man by attending to his resources or high status because these are usually achieved through competition with other members of the social and economical hierarchy... - - devendra singh & robert k. young, november 1995. ethology and sociobiology 16 ( 6 ) : 483 - 484. the theory of sexual selection by female choice, on the other hand, was greeted with interest mixed with skepticism ( wallace 1889 ; huxley 1938 ). wallace fully accepted intermale sexual selection but had serious doubts about the efficacy of female - choice sexual selection. his doubt concerned the adequacy of the proposed mechanism. can female choice exert a selective pressure that is consistent and strong enough to produce secondary sexual characters of adornment and display in males? the status of sexual selection by female choice is still unsettled. modern studies have confirmed the process for some types of male characters, but legitimate questions remain as regards other types of male characters... - - verne grant, october - november - december 1995. biologisches zentralblatt 114 ( 4 ) : 320. wallace presented a very clear interbreeding species definition, then immediately dismissed it in his treatise on speciation of the papilionidae of indonesia. ' species are merely those strongly marked races or local forms which, when in contact, do not intermix, and when inhabiting distinct areas are incapable of producing a fertile hybrid offspring. but as the test of hybridity cannot be applied in one case in ten thousand, and even if


or local forms which, when in contact, do not intermix, and when inhabiting distinct areas are incapable of producing a fertile hybrid offspring. but as the test of hybridity cannot be applied in one case in ten thousand, and even if it could be applied, would prove nothing, since it is founded on an assumption of the very question to be decided... it will be evident that we have no means whatever of distinguishing so - called " true species " from the several modes of [ subspecies ] variation here pointed out, and into which they so often pass by an insensible gradation '. wallace is first saying that it is practically impossible to make all the necessary crosses to test genetic compatibility. second, since theories of speciation involve a reduction in ability or tendency to interbreed, species cannot themselves be defined by interbreeding without confusing cause and effect... - - james mallet, july 1995. trends in ecology & evolution 10 ( 7 ) : 295. the adaptive significance of cryptic female coloration in birds is an old and hotly debated issue in animal behavior, being a source of great disagreement between a. r. wallace and c. darwin, the co - founders of natural selection theory... darwin ( 1871 ) believed that dull female coloration was a non - adaptive consequence of sex - limited inheritance. wallace ( 1889 ) proposed the hypothesis that cryptic female coloration functions to reduce predation risk at the nest. wallace ' s evidence included the observation that in many cavity - nesting species females are brightly colored, and males are more cryptic than females in species with sex role reversal. however, these results are also consistent with sexual selection theory. field tests of the nest predation hypothesis are rare, perhaps because extensive color variation among females within a sexually dimorphic species is uncommon... - - bridget j. stutchbury & joan s. howlett, may 1995. the condor 97 ( 2 ) : 559. aging is notoriously hard to explain in evolutionary terms. an early insight is due to alfred russel wallace, the co - founder of evolutionary theory. the gist of his argument is contained in the following quotation ( wallace, 1865 ) : " when one or more individuals have provided a sufficient number of successors, they themselves - - as consumers of nourishment in a constantly increasing degree - - are an injury to those successors. natural selection therefore weeds them out. " in the following it will be shown that this basic idea allows one to arrive at a quantitative prediction of


- as consumers of nourishment in a constantly increasing degree - - are an injury to those successors. natural selection therefore weeds them out. " in the following it will be shown that this basic idea allows one to arrive at a quantitative prediction of species - specific aging. it also enables a qualitatively correct prediction of sex - specific differential aging in two species. the slower aging of human females becomes understandable in evolutionary terms... - - reimara rossler, peter e. kloeden & otto e. rossler, may 1995. biosystems 36 ( 3 ) : 179. in frank tipler ' s newly published book ( 1994 ), the physics of immortality : modern cosmology, god and the resurrection of the dead, for example, the author claims " modern physics requires the god principle. " by this tipler means that the universe is structured in such a way that the laws of nature must give rise to intelligent life ; and once formed, the resurrection of all intelligence - - immortality - - is inevitable. " science now tells us, " tipler concludes, " how to go to heaven. " while tipler ' s science is modern, his argument is not. it is wallace ' s argument for the necessity of a higher intelligence clothed in modern physics... - - michael shermer, december 1994. skeptic 3 ( 1 ) : 70.... with the primary evidence missing in this historical mystery, we can only speculate on what really happened at down. the extreme interpretation of a conspiratorial cover - up is not supported by the evidence. if darwin were going to rig ( or allow to be rigged ) the editorial presentation of the papers to award him priority ; or worse, plagiarize from wallace certain needed ideas ( such as the divergence of species, as brooks suggests ), why announce the arrival of wallace ' s essay and submit it for publication in the first place? why not either just take what was needed, or, if wallace ' s essay added nothing new to the theory, just destroy the essay and letter and blame the loss on an inefficient postal service, or the mishandling of his mail at down, or whatever? if one is going to accuse darwin of such devious finagling as delicate arrangements or plagiarization, then would not the same guileful and scheming personality think of complete elimination of wallace ' s essay as a successful strategy?... - - michael she


of such devious finagling as delicate arrangements or plagiarization, then would not the same guileful and scheming personality think of complete elimination of wallace ' s essay as a successful strategy?... - - michael shermer, march 1995. skeptic 3 ( 2 ) : 83 - 84. several alternative explanations exist for the occurrence of symmetrical signals and symmetry preferences in nature. it has been suggested that some morphological symmetries arise inevitably from developmental processes. however, as wallace ( 1889 ) observed, the symmetrical body markings of wild animals are often lost or degraded in their domesticated descendants. this suggests that certain symmetries are not inescapable consequences of development, but are maintained by other selection pressures in nature... - - magnus enquist & anthony arak, 10 november 1994. nature 372 : 172. the naturalists ' concept of species as distinct reproductive units was carried over into the post - darwin period. it was stated by wallace ( 1889 ), eimer ( 1889 ), and others. i will present wallace ' s characterization of species in a paraphrased form. a species is an assemblage of individuals which : ( 1 ) are modified in structure, form, and constitution so as to be adapted to their particular conditions of life ; ( 2 ) are differentiated from other allied assemblages ; ( 3 ) reproduce their like : and ( 4 ) usually breed together ( wallace, 1889 ). some students of species in the early post - darwin period began to characterize species, not only as reproductive units, but as units of interbreeding. we see this in wallace ' s fourth point above : species are individuals " which usually breed together " ( wallace, 1889 ). according to poulton ( 1903 ) a species is " an interbreeding community ". karl jordan ( 1905 ) stated that the individuals of a species occur together in an area and form an interbreeding community ( " eine paarungsgemeinschaft " ). wallace ' s first point listed above puts adaptation into the set of characteristics of species. this was an innovation at the time and one which did not become generally accepted until much later... - - verne grant, october - november - december 1994. biologisches zentralblatt 113 ( 4 ) : 406. in their recent tree article, polak and trivers say that the study of symmetry and its fluctuations in biology was largely restricted to morphology and systematics until 1953.


december 1994. biologisches zentralblatt 113 ( 4 ) : 406. in their recent tree article, polak and trivers say that the study of symmetry and its fluctuations in biology was largely restricted to morphology and systematics until 1953. however, in 1889 a. r. wallace remarked that coloration patterns of wild animals are more symmetrical than those of their domesticated descendants ; he thought that symmetry would help specific recognition. in one respect wallace ' s observation seems paradoxical. domestic animals have less need to be cryptic than their wild counterparts, but, at least for humans, the presence of symmetry is a major failing of camouflage. symmetrical patterning gives away animals that are otherwise superbly concealed. the few cryptic animals that are asymmetrically patterned maybe the exceptions that prove this rule, one example is the wryneck ( jynx torquilla ), an unusual woodpecker... - - d. osorio, september 1994. trends in ecology & evolution 9 ( 9 ) : 346.... the riverine barrier hypothesis was first advanced by alfred russel wallace in 1849, when he argued that primate distributions were affected by river barriers and showed that the basin was divisible into four major geographic areas bounded by the amazon, negro, and madeira rivers. this hypothesis, although not mutually exclusive from others, has received recent attention and support. ayres ( 1986 ) and ayres and clutton - brock ( 1992 ) have confirmed wallace ' s original observation by documenting the correlation between the degree of private community similarity on opposite banks of amazonian rivers and river width, or flow rate. additionally, capparella has shown that the degree of genetic divergence among samples of understory bird species is related to river width. one explicit expectation of the riverine barrier hypothesis is that increasing divergence should relate positively to river size ( width, flow rate, etc. ). hence, differentiation should increase along both sides of a green river, from its headwaters to the mouth, as the barrier widens and the potential for cross - river gene flow diminishes. however, the expectation for any given taxon is likely to be complicated by the dynamic nature of floodplain rivers, because populations have the potential for passive transfer from one side to the other by river - bend cutoffs, or oxbow lake formation, through time... consequently expectations of the potential force of riverine barriers are likely to vary among taxa that occur in the river floodplain ( the seasonal flooded forest,


the other by river - bend cutoffs, or oxbow lake formation, through time... consequently expectations of the potential force of riverine barriers are likely to vary among taxa that occur in the river floodplain ( the seasonal flooded forest, or " varzea " of the amazon basin ) as opposed to those that are limited to upland, nonflooded forest, or terra firme. the pattern and degree of divergence may also depend on other ecological characteristics... - - james l. patton et al., august 1994. evolution 48 ( 4 ) : 1314.... the argument has been made that aesthetic criteria in general are secondary and essentially in the service of a more fundamental process. thus, wallace has disputed darwin ' s claim that female choices of maters reflect strictly aesthetic tastes, that is, beauty for beauty ' s sake ( wallace, 1889, 1892 ). rather, wallace insisted that beauty is likely to be associated with good health and vigor, which are deemed the primary bases for choice. the theoretical advantage that accrues to wallace ' s position is that sexual and natural selection are parsimoniously working in unison. within the classical darwinian perspective, female choice of the most flamboyantly adorned or colored male can imply choice of a mate vulnerable to predators and likely to produce offspring with similar vulnerabilities. none of this is intended to imply that either darwin or wallace is right or wrong. after the passage of more than a century, the issue is still under debate, although new experimental studies testing predictions from the two theories offer hope of an eventual resolution of the issue... - - nathan kogan, spring 1994. social research 61 ( 1 ) : 143.... in short, there are on every hand the most striking and conclusive evidences that the production and consumption of wealth have increased with even greater rapidity than the increase of population, and that, if any class obtains less, it is solely because of the greater inequality of distribution. what [ henry ] george had done with this argument, helfand argues, was to establish an economic equivalent of wallace ' s theory that the human brain changed the nature of the evolutionary process by its ability to create tools and alter the environment. george had argued that labor is the source of wealth, on grounds that " the richest countries are not those where nature is the most prolific ; but those where labor is the most efficient. "... - - lamar b. jones, april 1994. american


argued that labor is the source of wealth, on grounds that " the richest countries are not those where nature is the most prolific ; but those where labor is the most efficient. "... - - lamar b. jones, april 1994. american journal of economics and sociology 53 ( 2 ) : 252. the earliest discovery of avian visual mimicry was wallace ' s account of another case involving large aggressive models and smaller mimics that would otherwise have been expected to be among the models ' victims. the models are friarbirds of the philemon [ moluccensis ] superspecies which are among the largest members of a family ( meliphagidae or honey - eaters ) notorious for pugnacious behavior ; the models are orioles of the oriolus [ bouroensis ] superspecies ( family oriolidae ). wallace was struck by parallel geographical variation in plumage between friarbirds and orioles on two indonesian islands. subsequent study expanded wallace ' s observations in three respects... - - jared m. diamond, 24 february 1994. nature 367 : 684. the common idea that darwin behaved like a perfect gentleman throughout the wallace episode rests partly on the myth that he had some option other than those outlined above - - that he could have rushed his theory to press without so much as mentioning wallace. but unless wallace was even more saintly than he seems to have been, this would have brought a scandal that left darwin ' s name tainted, even to the point of endangering its connection to his theory. in other words : this option was not an option. the biographer who admiringly observes that darwin " hated losing his priority, but he hated even more the chance of being suspected of ungentlemanly or nonsporting conduct " is creating a distinction where none existed ; to have been thought unsporting would have threatened his priority... - - robert wright, 1994. in his the moral animal ( pantheon books ) : 306. a major stumbling block for darwinians was the absence of any fossil remains of humans in europe during the tertiary period. from this wallace had argued a priori that the human species had not spread widely upon the earth and was of recent origin. since fossil remains had been located only in the tropics, wallace concluded that these warm climes had been the cradle of human evolution... - - nancy j. christie, 1994. in roy macleod & philip j. rehbock, eds., darwin ' s laboratory : evolutionary theory


, wallace concluded that these warm climes had been the cradle of human evolution... - - nancy j. christie, 1994. in roy macleod & philip j. rehbock, eds., darwin ' s laboratory : evolutionary theory and natural history in the pacific ( university of hawai ' i press ) : 445. wallace is less well known for his lifelong insistence on the necessity for precise species distribution maps than he is for his much - disputed line. detailed knowledge of species distribution was the basis for wallace ' s efforts to formulate a general scheme of faunal regions. in one image, wallace ' s map redefined and unified the various notions of biological regions current in the first half of the nineteenth century, embodied the evolutionary history of the diverse biota of the east indian archipelago, and participated in a genre of visual representation extending into the contemporary culture... jane r. camerini, december 1993. isis 84 ( 4 ) : 727. fisher ( 1920 ) explains that the " essential difference " between plans such as those of wallace and his own " is that between redeemability and irredeemability. " but is there really an essential difference between always being able to " redeem " a gold certificate for a possibly varying quantity of gold, on the one hand, and always being able to purchase with irredeemable money a given quantity of gold at a possibly varying market price, on the other? so as an outsider to economics, wallace was free from the attachment to gold and thus advocated a stabilization policy that was more in the spirit of the quantity theory. he was also explicit about what fisher ( in his definite - reserve system ) left unspecified ; namely, the role of the treasury in injecting or withdrawing quantities of money from circulation. here was a true anticipator of the chicago school of the 1930s... - - don patinkin, summer 1993. economic quarterly 79 ( 3 ) : 18. the second story is that the thin martian atmosphere is but a remnant of a once much thicker atmosphere, most of which long ago escaped to space [ cf., wallace, 1907 ]. other things being equal, because it is smaller, escape is easier from mars than from earth or venus. several escape mechanisms have been suggested, including some that could be operative today. a possibly important example of the latter is the nonthermal escape of nitrogen. hydrodynamic escape and impact erosion of the atmosphere ( a. k. a. atmospheric cratering ) are two potentially much


, including some that could be operative today. a possibly important example of the latter is the nonthermal escape of nitrogen. hydrodynamic escape and impact erosion of the atmosphere ( a. k. a. atmospheric cratering ) are two potentially much more effective escape mechanisms that should have been operative early... - - kevin j. zahnle, 25 june 1993. journal of geophysical research e 98 ( 6 ) : 10, 889.... the value of living organisms as an intellectual resource is another compelling reason for preserving biotic diversity. it provides the materials that allow us to understand the living world, whatever our reasons for doing so. extinction is depriving us of much of the crucial evidence. among the measures that wallace advocated was the establishment of a system of strategically located forest reserves where a representative sample of the biota could be preserved and studied by naturalists... - - michael t. ghiselin, spring 1993. pacific discovery 46 ( 2 ) : 23. selection for genetic isolation has been called the wallace effect by grant, in honor of a. r. wallace who first suggested it ( wallace 1889 ). control of a species ' altitudinal boundary by a pathogen - environment interaction may provide an appropriate arena for the wallace effect. the scenario for speciation suggested above begins with a very unlikely event : establishment of a new disease - resistant population outside the normal habitat of the parent species. though unlikely, such speciation across a " pathological barrier " requires no changes of climate, elevation of mountain chains, or other large scale phenomena. it suggests that the potential for the establishment of peripheral isolates in new ecological settings may exist at the margin of a great many species. this scenario is similar to the concept of the " upstart species " of harper or of new species " budding off ' from older species... - - william burger, december 1992. biotropica 24 ( 4 ) : 569. for both monochromatic and polychromatic species, pelage pigmentation would be helpful for identifying conspecifics, especially at distances where odor and vocalizations would be unreliable cues. in polychromatic species it would also narrow the range of choices within a herd when looking for the mother, particularly when her head cannot be seen clearly. alfred russel wallace recognized the significance of body pigmentation when he wrote in 1889, under the subject of " colour as a means of recognition " : " if we consider the habits and life - histories of those


when her head cannot be seen clearly. alfred russel wallace recognized the significance of body pigmentation when he wrote in 1889, under the subject of " colour as a means of recognition " : " if we consider the habits and life - histories of those animals which are more or less gregarious, comprising a large proportion of the herbivora,... we shall see that a means of ready recognition of its own kind, at a distance or during rapid motion, in dusk of twilight or in partial cover, must be of the greatest advantage and often lead to the preservation of life. " within a colour category, the young would have to rely on other cues, be they visual, auditory, or olfactory. for example, the length of pelage was one of the cues eliminated in this study by cutting the does ' hair, because in a previous study i noticed that the offspring of long - haired females tended to solicit females with long hair like that of their mothers. although cues present in the head are probably important for individual recognition, at a distance the fine detail of facial characteristics might not be as discernable as markings on parts of the body with more surface area. the specific visual cues used for recognition should depend on the characteristics of the group or species, the habitat in which the species is found, and the perceptual capabilities of the developing individuals... - - carlos r. ruiz - miranda, november 1992. behaviour 123 ( 1 - 2 ) : 136 - 137. for paley, the epiglottis could not evolve in this manner ; hence, some form of causality other than change origin is called for. paley ' s answer was " an intelligent and designing creator. " soon other thinkers followed paley ' s lead concerning the impact of the argument from perfection. in one of the most amazing shifts in the history of ideas, alfred russel wallace ( 1823 - 1913 ) employed what may be considered an indirect use of the argument from perfection on an a fortiori basis against the very theory of natural selection that he had founded with charles darwin... - - john t. baldwin, april 1992. harvard theological review 85 ( 1 ) : 112.... on the one hand, motivated by the biological evidence discussed, but restricting themselves to a one - dimensional model of world reality, goldschmidt and gould ( themselves standing outside the argument from perfection tradition ) of necessity turn for an alternative model of origins to a refined concept of the " hopeful monster " theory wholly


but restricting themselves to a one - dimensional model of world reality, goldschmidt and gould ( themselves standing outside the argument from perfection tradition ) of necessity turn for an alternative model of origins to a refined concept of the " hopeful monster " theory wholly explainable by empirical principles within a materialistic framework. on the other hand, paley, wallace, mivart, bergson, taylor, kenny, plantinga, and polkinghorne, prompted by similar biological evidence but remaining open to a wider model of reality ( one that can include a trans - empirical dimension ) and to a dynamic relationship between god and the world, conclude that the evidence points more convincingly to some kind of originating causality that in the final analysis lies beyond the reach of " methodological naturalism. "... - - john t. baldwin, april 1992. harvard theological review 85 ( 1 ) : 119. alfred russel wallace developed a theory of evolution by natural selection at the same time that charles darwin did. he applied his theory to one of the earliest scenarios of human evolution. he related the split between the first human beings and the apes to the habitats in which they lived. wallace proposed that hominids, our bipedally walking ancestors, arose on the great plains and high plateaus of eurasia, isolated there by shrinking forests. his deduction was based on the fact that apes today live in dense forested areas. wallace thought, therefore, that bipedally striding humans must have evolved in open, flat areas. darwin disagreed on the geography, believing that a tropical environment with abundant fruit was our ancestral hominids ' environment. he preferred an african origin for the human lineage. the chimpanzee and gorilla, he pointed out, were both african and the closest living primate relatives to humans... - - noel t. boaz, march 1992. earth 1 ( 2 ) : 37. these findings show that wallace ' s hypothesis can be verified for a broad category of population genetic models and that, therefore, the wallace effect indeed deserves a central position in speciation theory. by outlining the effects of gametic phase imbalance, the findings also point at the forces which could possibly set up barriers to speciation : asymmetric gene flow between parapatric populations, and asymmetric cross - incompatibility in both parapatric and sympatric ( sub - ) populations. asymmetry in cross - incompatibility describes the situation where in one population the rejection of cross - mating


, and asymmetric cross - incompatibility in both parapatric and sympatric ( sub - ) populations. asymmetry in cross - incompatibility describes the situation where in one population the rejection of cross - matings is markedly stronger than in the other population. however, whether these conditions actually suffice to inhibit speciation must be proven in each special case... - - hans - rolf gregorius, february 1992. journal of theoretical biology 154 ( 3 ) : 397.... wallace ' s narrative eye, like darwin ' s, allows him to transcend time through visual analogy, but it is the european model of cultural progress rather than biological history that flashes before the reader. the narrative motion of the european mind searching backward through its own memory is obscured, and the narrative motion of the tropical landscape advancing into the european landscape is foregrounded. wallace ' s representation suggests than in looking at the trees he is not simply experiencing perceptual confusion ; he is perceiving future forms in present ones. the link between trees and pillars, between tropical and european, is thus seen as a historical inevitability rather than an optical illusion or perceptual accident. where darwin ' s illusions increase formal variety, however, wallace ' s limit it. rather than a single form blossoming into multiple analogous forms, wallace ' s eye perceives several different species in terms of a single european form. the distinction between darwin ' s and wallace ' s representational strategies roughly correlates to the differences in their evolutionary theories. darwin believed in random competitive evolution while wallace believed in adaptive, environmental evolution... - - james krasner, 1992. in his the entangled eye : visual perception and the representation of nature in post - darwinian narrative ( oxford university press ) : 114.... in wallace ' s nature all selection is purposeful and relatively precise ; nature tends toward utility, and clears way all forms that are not useful. james ' s theory of vision can be seen as the perceptual corollary to wallace ' s evolutionary theory. the jamesian mind, like wallace ' s evolutionary nature, establishes a formal standard that must be met, and all those forms that fail to meet that standard are eliminated ; in wallace ' s nature they die off, in james ' s vision they go unperceived. it is therefore appropriate that wallace should use a jamesian representational model. where darwin portrays visual forms mutating and


standard are eliminated ; in wallace ' s nature they die off, in james ' s vision they go unperceived. it is therefore appropriate that wallace should use a jamesian representational model. where darwin portrays visual forms mutating and multiplying as they compete for space in the reader ' s perceptual field, wallace portrays the selection of forms according to an imageable standard of reference. moreover, because this formal standard is european, the forms of nature are selected according to the standard of reference of european experience - - the viewer perceives trees as pillars, and those trees that look less like pillars are ignored. wallace ' s representation of evolution thus involves the reader in a more and more familiar world... - - james krasner, 1992. in his the entangled eye : visual perception and the representation of nature in post - darwinian narrative ( oxford university press ) : 115. until just before 1880 wallace had firmly believed " that vaccination was a scientific procedure, and that jenner was one of the great benefactors of mankind. " as a young man he had voluntarily undergone vaccination and subsequent revaccination, just before leaving for south america on a naturalistic trip. he had never questioned the effectiveness of the operation until reading several anti - vaccination texts and meeting william tebb, the 1870 successor of john and richard gibbs as leader of the anti - vaccination league and founder of the anti - vaccination society of america. convinced by tebb ' s arguments, wallace joined him in the battle for the new cause. aware of his ignorance on medical matters, wallace always based his arguments on statistic figures rather than on strictly sanitary aspects. harry clements, his biographer, writes : " no one was apparently able seriously to challenge him on the figures. "... - - giacomo scarpelli, 1992. nuncius ( italy ) 7 ( 1 ) : 115 - 116.... these moral principles were also applied to another field of study, that of the so - called " psychical research " which caught wallace ' s interest very early, in fact earlier than we might possibly think. spiritism, in wallace ' s mind, had a eudaemonist socratic meaning : ghosts were seen as moral and spiritual guides to man. wallace then developed the idea of man as center of a pre - ordained universe, in which the pain which man is subject to being the most sensitive creature, and the evil which he must fight since he is capable


as moral and spiritual guides to man. wallace then developed the idea of man as center of a pre - ordained universe, in which the pain which man is subject to being the most sensitive creature, and the evil which he must fight since he is capable of discerning, are seen as necessary steps towards the completion of moral rather than organic developments, necessary to enter into a superior spiritual sphere. we can now truly understand this sentence : " the whole purpose, the only raison d ' etre of the world [... ] was the development of human spirit in association with the human body "... this conception of a pre - existing order and a synchronicity can explain the logic which backed wallace ' s opinions and attitudes... - - giacomo scarpelli, 1992. nuncius ( italy ) 7 ( 1 ) : 120 - 121.... wallace... brought forth an alternative explanation which involved totally different powers. man has the faculty of artificially selecting vegetable and animal species ; similarly a higher intelligence could have controlled and directed natural selection in the human development process, in a particular and highly ethical aim... effectively, wallace, induced by the moral ideal earlier mentioned, was trying to find a solution that would not clash with his vision of harmonia naturae and undermine the theory of natural selection with whatsoever extension or correction. his was not a denial of the theory but, paradoxically, the result of his excessively rigourous attitude. wallace, the hyperselectivist, preferred to involve a superior intellect, in other words a deus ex machina, rather than admit that his primary theory might possibly have been less absolute... - - giacomo scarpelli, 1992. nuncius ( italy ) 7 ( 1 ) : 126.... wallace was driven in his crusade by ethical and social issues, as well as the intention of preventing the disruption of the biological balance. this was altogether a kind of civil protest aimed towards a general reform of society, freed from imposition. wallace believed that an improvement of the population ' s economic conditions would have resulted in higher hygienic standards and a richer diet, and consequently, in a decreased spread of diseases, smallpox included. he also envisaged the creation of a ministry of health employing teams of doctors. these purposes, which seem so obvious today, were in his time little less than revolutionary. it can be said that wallace foresaw the creation of national health service... - - giacomo scarpel


a ministry of health employing teams of doctors. these purposes, which seem so obvious today, were in his time little less than revolutionary. it can be said that wallace foresaw the creation of national health service... - - giacomo scarpelli, 1992. nuncius ( italy ) 7 ( 1 ) : 128. man ' s place in the universe. a. r. wallace ( mcclure, phillips, new york, 1903 ). a famous coauthor of darwin ' s discovery anticipated in the last chapter of his book almost all versions of modern ap [ the anthropic principle ]... - - yuri v. balashov, december 1991. american journal of physics 59 ( 12 ) : 1072. wallace did not try to explain distribution patterns by invoking the occurrence of unique events but rather by recourse to general principles. for wallace that general principle was geological change. there are numerous passages in wallace ( 1880 ) that confirm his appreciation of the importance of geological change in understanding distribution patterns in indonesia. his discussion of the faunal relationship between the malay peninsula and the islands of borneo, sumatra, and java is detailed and provides a clear statement of his position. having noted the overall similarity of this area ' s flora and fauna to that of india, he continued on the greater similarity of the mammals and birds of borneo and sumatra than those of borneo and java, and on the high degree of endemism of the javan fauna... - - b. michaux, september 1991. australian systematic botany 4 ( 1 ) : 26.... although this is a rather brief summary of the distribution patterns that wallace recognised in indonesia, it does, i believe, accurately reflect the major patterns he observed. his interpretations of these patterns, based as they were on an incomplete understanding of the dynamic nature of the earth ' s surface, are only really of historical interest. wallace ' s attempt to understand distributional patterns in terms of geological change was doomed from the start because neither he nor anyone else at the time realised that land could move laterally as well as vertically... - - b. michaux, september 1991. australian systematic botany 4 ( 1 ) : 27. discrimination involves recognition in the signal receiver that a stimulus, or configuration of stimuli, belongs to some discrete category. the importance of design for discriminability has been recognized since wallace ( 1867 ) suggested that distasteful insect larvae '... required some distinctive mark, something by which they may


or configuration of stimuli, belongs to some discrete category. the importance of design for discriminability has been recognized since wallace ( 1867 ) suggested that distasteful insect larvae '... required some distinctive mark, something by which they may be contrasted with and separated from the agreeable larvae, in order that they might be freed from the attacks of birds ' and that ' brilliant colouration would be such a distinction as was required '. warning colours and patterns should therefore look different from those of the prey for which predators normally hunt... - - tim guilford & marian stamp dawkins, july 1991. animal behaviour 42 ( 1 ) : 5. successive generations of evolutionary biologists, beginning with august weismann and alfred r. wallace, have refined our understanding of the evolution of senescence to the point where we now have pretty good reason to believe that in a species like our own aging occurs because natural selection places higher priority on turning out progeny to carry our genes forward than on keeping individuals going ; in effect, late survival is sacrificed for reproduction. extending through a more diverse range of reproductive patterns, the burgeoning discipline of evolutionary life - history theory provides us with the intellectual framework to approach questions like why some species get only a single shot at reproduction ( semelparity ) while other get more ( iteroparity ) and why species differ in their longevities... - - caleb e. finch, 28 june 1991. science 252 ( 5014 ) : 1864.... in wallace there was support for the nationalization of land and for the economic emancipation of women. the latter reform he actually justified in evolutionary terms, thereby giving rise to a form of social wallaceism. his point was that women were currently prevented, by their social and economic disadvantages, from fully exercising their selective role in the choice of mate. although he sometimes felt that darwin attached too great an importance to sexual selection in the mechanics of evolution, wallace was nevertheless convinced that female emancipation could only benefit posterity... - - john hedley brooke, 1991. in his science and religion ; some historical perspectives ( cambridge university press ) : 294 - 295.... the sheer improbability of the emergence of man deeply impressed alfred russel wallace. contingency had piled upon contingency with each critical stage in evolutionary divergence. in a book written late in life, man ' s place in the universe ( 1903 ), he turned the argument against physicists and astronomers who were scouring


contingency had piled upon contingency with each critical stage in evolutionary divergence. in a book written late in life, man ' s place in the universe ( 1903 ), he turned the argument against physicists and astronomers who were scouring the heavens for planets having a physical environment comparable with that of the earth and on which intelligent life might be presumed to have evolved. properly understood, wallace argued, the theory of evolution told against such a possibility - - certainly against the emergence of intelligence akin to human. however close the physico - chemical environment to that on earth, it was inconceivable that the evolutionary process on other worlds could have followed the same nuanced path as on earth. one minor deviation at an early stage and the whole process would take an entirely different course... - - john hedley brooke, 1991. in his science and religion ; some historical perspectives ( cambridge university press ) : 315. wallace ' s scientific case rested on his conclusion that the human brain, including that of the most primitive peoples, was more powerful than was necessary for survival. for a large part of his early life wallace had lived among primitive peoples in south america and southeast asia, an experience that convinced him that these people, simple as they have appeared in mind and action, were equal in intelligence to europeans. as the modern anthropologist loren eiseley remarked, wallace displayed " scarcely a trace of the racial superiority so frequently manifested in nineteenth - century scientific circles, " in which were included darwin and thomas huxley. if human beings possessed brain capacities beyond what was needed for survival, wallace reasoned, then how could natural selection bring about its evolution? where was the " survival value " of that capacity if that capacity was not fully used? after all, natural selection improved an organ only through its adaptation to the pressure of environment. in the case of the human brain, however, the capacity was greater than human beings really required or that the pressure of environment could account for. wallace logically concluded on those grounds that " some higher intelligence directed the process by which the human race was developed. "... - - carl n. degler, 1991. in his in search of human nature ; the decline and revival of darwinism in american social thought ( oxford university press ) : 60.... it will be recalled that darwin could find no useful value in the physical ( racial ) differences among human groups. thus he could not account for those differences through the operation of natural selection. he did, however, accept the common


60.... it will be recalled that darwin could find no useful value in the physical ( racial ) differences among human groups. thus he could not account for those differences through the operation of natural selection. he did, however, accept the common anthropological view of the time that the differences in levels of culture or civilization which occurred among the diverse peoples of the world derived from differences in their biological capacities. some cultures were higher than others because the people in those societies were biologically superior. that was the opening in his theory of human evolution through which racism entered. it was that opening which wallace closed with his conception of the intellectual equality and therefore the equal cultural capacity of all peoples. as things turned out, wallace looked to other ways and matters in his effort to make evolution less competitive and threatening. he did not develop any further his assertion of the mental equality of all peoples, or at least few took notice of its relevance. yet that was the precise argument, elaborated and tirelessly defended, that undermined in time the concept of racism in america. its elaboration and defense underpinned the concept of culture, an idea that in the twentieth century became not only an alternative to a racial explanation for human behavioral differences but also a central concept in social science... - - carl n. degler, 1991. in his in search of human nature ; the decline and revival of darwinism in american social thought ( oxford university press ) : 61.... wallace ' s supernatural explanation gained few followers among social scientists in the second half of the twentieth century, but his assertion of the special, indeed unique, nature of man, because of his brain, continued to influence many, directly or indirectly. the eminent modern american anthropologist loren eiseley, for example was among them. his sympathetic response to wallace reflects the views of many other american social scientists today. eiseley did not doubt that wallace has a better understanding of the roots of human nature than darwin. in his book darwin ' s century, eiseley contrasted darwin ' s conception with that of wallace. " the mind of man, by indetermination, by the power of choice and cultural communication, " he wrote, " is on the verge of escape from the blind control of that deterministic world with which the darwinists had unconsciously shackled man. the inborn characteristics laid upon him by the biological extremists have crumbled away, " he was relieved to report. in eiseley ' s judgement, wallace stood out among evolution


the darwinists had unconsciously shackled man. the inborn characteristics laid upon him by the biological extremists have crumbled away, " he was relieved to report. in eiseley ' s judgement, wallace stood out among evolutionists of his own time because he recognized even then that human beings had escaped from biological evolution. " wallace saw and saw correctly, that with the rise of man the evolution of parts was to a marked degree outmoded, that mind was now the arbiter of human destiny. "... - - carl n. degler, 1991. in his in search of human nature ; the decline and revival of darwinism in american social thought ( oxford university press ) : 330. wallace ( 1865 ) hypothesized that sex - limited mimicry, in which palatable females are the only sex to mimic unpalatable butterflies, arises because females fly more slowly than males and hence are more vulnerable to predation. our results from the within - lineage analyses are in agreement with wallace ' s hypothesis. evolutionarily, palatable males have larger thoraces, maximizing flight muscle, and smaller abdomens, minimizing load on the wings, probably to maximize flight speed ; whereas females have retained large abdomens, probably to maximize egg load. counter - selection for fecundity may operate against faster flight speeds, and females may be reproductively constrained to evolve alternative means of avoiding predation, such as mimicry. if females fly more slowly, they may be predisposed to fly like an unpalatable model... - - robert srygley & peng chai, 11 october 1990. oecologia 84 ( 4 ) : 498.... there simply weren ' t any lists of darwinian tenets that would have been accepted by all the leading darwinians and rejected by all the main non - darwinians in the first decade or so following the publication of the origin. both the darwinians charles lyell and asa gray and the non - darwinians the duke of argyll and st. george mivart, for example, thought that natural selection must be supplemented by some sort of " directing force " in order to account for the relevant phenomena, while darwin consistently denied the need for such an additional mechanism ( argyll 1877 ; gray 1884 ; mivart 1871 ). conversely, neither the darwinians alfred russel wallace and charles lyell nor the non - darwinians st. george mivart and william whewell


for such an additional mechanism ( argyll 1877 ; gray 1884 ; mivart 1871 ). conversely, neither the darwinians alfred russel wallace and charles lyell nor the non - darwinians st. george mivart and william whewell thought that human beings could be included under the same explanatory scheme ( whatever this might be ) that was used to account for the history and behavior of " lower " animals, while darwin maintained that they could... - - doren recker, september 1990. philosophy of science 57 ( 3 ) : 463. the efforts to denigrate darwin serve only to conceal the real differences between the two naturalists ' approach to transmutation. careful reading of wallace ' s paper reveals that in several important respects his theory failed to duplicate the essence of darwin ' s thinking. wallace had no interest in artificial selection and refused to treat it as analogous to the natural process even in later years. his mechanism did not even address the basic question of how selection acts on individual differences to change a population, because he was interested in how one well - marked variety ( what we now call a subspecies ) could replace others. once it is recognized that in writing of natural selection acting on varieties wallace was thinking of subspecies rather than individual variations, it can be seen that his paper does not contain a description of what darwin saw as the basic mechanism of change. wallace simply assumed that species split into varieties - - he did not seek to explain how this all - important first step occurs. it has also been suggested that wallace failed to appreciate the full power of selection because he treated the varieties as struggling against nature, not struggling against each other... - - peter j. bowler, 1990. in his charles darwin ; the man and his influence ( basil blackwell ) : 113.... wallace ' s darwinism of 1889 provided a clear and comprehensive survey of the theory and of the relevant areas of biology. except in the case of the origin of the human mind, wallace was an extreme selectionist ; unlike darwin, he would have nothing to do with any other mechanism of evolution. this position soon became known as ' neo - darwinism ' to distinguish it from the more flexible form of the theory which darwin himself had advocated and which had gained support precisely because it allowed selection to be relegated to the status of a secondary mechanism... - - peter j. bowler, 1990. in his charles darwin ; the man and his influence ( basil blackwell ) : 210. the good parent process is a mechanism


because it allowed selection to be relegated to the status of a secondary mechanism... - - peter j. bowler, 1990. in his charles darwin ; the man and his influence ( basil blackwell ) : 210. the good parent process is a mechanism for the evolution of epigamic traits that is distinct from the fisherian process and the good genes process. in the good parent process, direct selection on females to discriminate among males on the basis of male parental quality leads to the evolution of a trait that provides female with honest ( accurate and precise ) information regarding the non - heritable component of parental quality in a potential mate. wallace ( 1891, 1901 ) recognized the potential of such a mechanism, but he had no way to consider rigorously the effects of inheritance. the good parent process is also different from darwinian sexual selection ( darwin 1871 ), because females are not necessarily attracted by a good parent trait. a trait that evolves via the good parent process only enhances the attractiveness of high - quality males... - - guy a. hoelzer, december 1989. animal behaviour 38 ( 6 ) : 1075. since wallace ( 1889 ), a number of authors have argued that isolating barriers could be positively selected for their isolating property to prevent the formation of hybrids and to actively promote divergence and speciation. however, being a second order effect, the selective forces are likely to be weak, and, as levin points out, in practice it is going to be very difficult to distinguish this effect from other forms of competition and selection... - - mark r. macnair, february 1989. genome 31 ( 1 ) : 204 - 205. wallace, on the other hand, insisted on the validity of the " uniform and consistent testimony of our senses ". it is complete fallacy, so he argued, that only propositions could be demonstrated and phenomena could not be. " the direct testimony of the educated senses guided by reason was of higher validity than any complex results of reason alone. " according to wallace, testimony was trustworthy if the witness was in full possession of the senses and in agreement with the reports of other witnesses. was it really true, asked wallace rhetorically, that a member of the house of peers like lord lyndsay - - who had recently converted to spiritualism - - " can not be trusted as a faithful witness? " if the witness were insane or deluded, wallace argued, they would also be unable to use carpenter ' s mathematical reasoning..


nothing at all when being devoured. " he goes further to assert ( very strongly ) that " birds, mice, squirrels, and the like, do not get limbs broken by falls, as we do, " and that, in sum, " whatever pain exists is not long - continued " ( wallace 1911, 404 - 405 )... - - david oates, december 1988. zygon 23 ( 4 ) : 445. darwin ' s response is, on the face of it, rather puzzling. why did he not protest wallace ' s assertion that selection works principally through the elimination of unfavorable variants? historians generally agree that the acknowledgment of selection as a negative force - - removing inferior variants and thus maintaining the " type " - - long predated darwin. in this perspective, darwin ' s achievement lay in his recognition that selection was " a creative process and not merely a sieve. " but there is no evidence that his dissents from wallace ' s essentially negative view. perhaps historians ' radical distinction between natural selection as a creative force and as executioner of the unfit - - that is, as " nature ' s broom " - - was not recognized by darwin... - - diane b. paul, fall 1988. journal of the history of biology 21 ( 3 ) : 417 - 418. the great american interchange was first recognized by wallace ( 1876 ), but it has taken another hundred years of intense paleontological study by ameghino, matthew, scott, patterson, simpson, webb, and others to clarify patterns of dispersal. it is only during the last decade, moreover, that greater precision in dating the sediments containing interchange taxa has provided a firm time frame for various aspects of the event. it is now possible to assess the interchange in detail, and to analyze the tempo and mode of dispersal and the rates of extinction and origination in successive faunas through time. as a result, the great american interchange represents the best - documented example in the fossil record of the intermingling of two long - separated continental faunas... - - larry g. marshall, july - august 1988. american scientist 76 ( 4 ) : 380.... " i should be extremely glad now to publish a sketch of general views in about a dozen pages or so ; but i cannot persuade myself that i can do so honourably. wallace says nothing about publication, and i enclose his letter. but as i had not intended to publish any sketch


a sketch of general views in about a dozen pages or so ; but i cannot persuade myself that i can do so honourably. wallace says nothing about publication, and i enclose his letter. but as i had not intended to publish any sketch, can i do so honourably, because wallace has sent me an outline of his doctrine? i would far rather burn my whole book, than that he or any other man should think that i had behaved in a paltry spirit. do you not think his having sent me this sketch ties my hands? i do not in least believe that that [ sic ] he originated his views from anything which i wrote to him " [ darwin ' s words ]... - - barbara g. beddall, spring 1988. journal of the history of biology 21 ( 1 ) : 52.... in the narrow focus espoused both by the participants in the events leading up to and including the " joint papers, " and by their successors, priority in this case has been treated as a " single event, " a zero - sum game with winners and losers, an occasion when " editorial manipulation " and " delicate arrangements " could be invoked. but, as seen above, the matter is far more complex than this approach would indicate. it requires a broader perspective in which the enormous contributions made by both darwin and wallace can be recognized. in game theory this would be a non - zero - sum game, where both darwin and wallace benefited from the work of the other, thus becoming codiscoverers of the theory of evolution by means of natural selection. if this interpretation of the events is rejected, the status of the matter reverts to a zero - sum game, which brings back with it not only its winners and losers, but also the problems of " editorial manipulation " and " delicate arrangements, " as posed by kohn and nelson... - - barbara g. beddall, spring 1988. journal of the history of biology 21 ( 1 ) : 62. strangely enough, it was a. r. wallace, not darwin, who suggested an explicit associative hypothesis integrating learning theory with natural selection. in a paper entitled " on the origin of food aversion paradigms, " garcia and hankins present the case for a darwin - wallace conditioning theory initiated in 1866 and experimentally verified by 1887. their theory was actively generating research 2 decades before pavlov began his studies in classical conditioning, and 3 decades before thorndike presented his thesis on instrumental


the case for a darwin - wallace conditioning theory initiated in 1866 and experimentally verified by 1887. their theory was actively generating research 2 decades before pavlov began his studies in classical conditioning, and 3 decades before thorndike presented his thesis on instrumental conditioning. this pioneer effort culminated in today ' s research area, narrowly labeled " conditioned taste aversion. " more broadly considered, this paradigm is representative of homeostatic conditioning which tolman ( 1949 ) called " cathexis " ; when responding to survival needs, organisms come to cherish one particular type of food and drink, or one given type of mate, and to abhor others... - - robert c. bolles & michael d. beecher, eds., 1988. in their evolution and learning ( lawrence erlbaum associates ) : 29.... wallace had traveled widely in south america and the south pacific as a naturalist and collector of exotic specimens. his observations of native peoples had convinced him that the intellectual and moral faculties required by the aboriginal way of life were not markedly different from those needed by mammals generally to survive in their respective ecological situations. yet aborigines brought to england and educated there had the capacity to acquire the behavioral sophistication of modern europeans. thus, aborigines had moral and intellectual capacities far exceeding the immediate requirements of the environments in which they had evolved. therefore the intellectual capacities of primitive man, and by implication modern man, could not be the result of natural selection... - - robert c. bolles & michael d. beecher, 1988. in their evolution and learning ( lawrence erlbaum associates ) : 41. the adaptive nature of warning, or ' aposematic ' colour patterns seemed clear a century ago ( wallace, 1867, 1878 ; poulton, 1890 ), but recently it has been debated whether ' individual ' natural selection may explain their initial evolution. fisher ( 1930 ) had earlier suggested a similar problem with the evolution of unpalatability. previous explanations depend purely on selection to explain the evolution of warning colours. here we propose that drift, combined with natural selection, may also be important... - - james mallet & michael c. singer, december 1987. biological journal of the linnean society 32 ( 4 ) : 338.... although mimicry strongly suggests that colour patterns are used as warning signals, there is only anecdotal evidence that warning colours are easier to learn than non - warning colours. traditionally, it has been


32 ( 4 ) : 338.... although mimicry strongly suggests that colour patterns are used as warning signals, there is only anecdotal evidence that warning colours are easier to learn than non - warning colours. traditionally, it has been assumed that the bright colours of unpalatable insects are more efficient signals ( wallace, 1867, 1878 ). birds seem to learn to avoid conspicuous prey more easily, and humans use bright colours in warning signs. however unpalatable insects could be brightly coloured for other reasons... - - james mallet & michael c. singer, december 1987. biological journal of the linnean society 32 ( 4 ) : 338.... in the pages of the encyclopedia britannica, over several editions, alfred russel wallace argued the case for acclimatization. he was more careful than most, at that stage, in distinguishing between domestication, naturalization and acclimatization. and yet arguing from first evolutionary principles and from plant and animal biogeography, he urged that " numerous facts in the distribution of races show that man must, in remote ages at least, have been capable of constitutional adaptation to climate ". in more recent times, the migrations of the jews, and the settlement of the dutch in south africa, the english - speaking peoples in america and australia, and the spanish in south america all demonstrated that complete acclimatization was entirely possible... - - david n. livingstone, december 1987. history of science 25 ( 4 ) : 381.... but now that the monogenist thesis had triumphed, acclimatization followed as a natural consequence. similar deductions were drawn by a. r. wallace : " numerous facts in the distribution of races show that man must, in remote ages at least, have been capable of constitutional adaptation to climate " he urged. hence, " if the human race constitutes a single species, then the mere fact that man now inhabits every region, and is in each case constitutionally adapted to the climate, proves that acclimatization has occurred. "... - - david n. livingstone, december 1987. history of science 25 ( 4 ) : 386. wallace ' s view was kindred in spirit to henry george ' s progress and poverty ( 1879 ), although wallace had less regard for the market. both saw man as needing land. their mutual disapproval of parnellism brought them together, and both submerged methodological differences to further their common concept. wallace gave


' s progress and poverty ( 1879 ), although wallace had less regard for the market. both saw man as needing land. their mutual disapproval of parnellism brought them together, and both submerged methodological differences to further their common concept. wallace gave him a platform when george toured britain. wallace cast george as a theorist who confirmed wallace ' s inductive argument, perhaps underrating george ' s journalistic background. for many years single tax and land nationalization were closely linked by friend and foe... - - mason gaffney, 1987. in john eatwell, murray milgate & peter newman, eds., the new palgraves : a dictionary of economics ( macmillan ), volume 4 : 850. according to both spencer and wallace, a natural principle of evolution inexorably led to the moral perfection of man. wallace, of course, had a different principle in mind than spencer ' s device of adaptation through the inherited effects of habit. he nonetheless believed that the principle of natural selection would add further support to spencer ' s primary vision, the view that man ' s moral character was not only a goal of evolution, but also a chief means of progress toward the perfection of human nature... - - robert j. richards, 1987. in his darwin and the emergence of evolutionary theories of mind and behavior ( university of chicago press ) : 165 - 166.... evolutionary theory, as darwin himself admitted in the origin, remained mute concerning how life and consciousness first arose in the universe ; it could only account for subsequent transformations. just so, wallace now proclaimed, natural selection brought no clear perception of the origins of specifically human intellect and moral feeling. he was persuaded that these distinctive capacities must have originated under the influence of higher powers, intelligences who shepherded the progressive development of mind through the ages... - - robert j. richards, 1987. in his darwin and the emergence of evolutionary theories of mind and behavior ( university of chicago press ) : 178.... contemporary primitives and our ancestors thus had latent mental qualities that could not be explained by natural selection, which demanded that selected traits confer immediate advantage, not simply promise it. wallace ' s contacts with the spirit world convinced him that higher intelligences rather than natural selection controlled human evolution. wallace forthrightly claimed that a conversion to spiritualism proximately caused his rejection of natural selection as an adequate principle to explain human evolution ; and virtually all historians have taken him at his word. but we need not. for after


evolution. wallace forthrightly claimed that a conversion to spiritualism proximately caused his rejection of natural selection as an adequate principle to explain human evolution ; and virtually all historians have taken him at his word. but we need not. for after all, wallace might well have chosen to regard natural selection as the disposing instrument of higher spiritual powers and to have held survival of the fittest as a secondary cause... - - robert j. richards, 1987. in his darwin and the emergence of evolutionary theories of mind and behavior ( university of chicago press ) : 181.... huxley tarried only a short while over wallace ' s demur about natural selection in the case of man. he derived from wallace ' s own writings about savage life descriptions of the extraordinary mental feats such life actually required - - knowledge of a vast territory, reading signs of game or enemies, discovery of properties of plants and habits of animals, and so forth. " in complexity and difficulty, " huxley estimated, " the intellectual labour of a ' good hunter or warrior ' considerably exceeds that of an ordinary englishman. " wallace had simply miscalculated the brain power the savage actually needed for survival ; thus neither primitive man nor modern native likely had in excess what could be delivered by natural selection or augmented by entering into civilized life. on the question of the moral sense, huxley could " find nothing in mr. wallace ' s reasonings which has not already been met by mr. mill, mr. spencer, or mr. darwin. "... - - robert j. richards, 1987. in his darwin and the emergence of evolutionary theories of mind and behavior ( university of chicago press ) : 227. and in the growth of biological thought ernst mayr comments : " in his letter, wallace said that if darwin thought his paper sufficiently novel and interesting, he should send it to lyell and, presumably, submit it for publication ( the original wallace letter is no longer in existence ). " but it is clear that wallace did not ask darwin to arrange for publication. unfortunately, as mayr notes, the letter that accompanied wallace ' 1s paper is lost. however, we have darwin ' s word for it that there was no such instruction. on the same day that wallace ' s paper arrived, darwin wrote an anguished letter to lyell, in which he refers to wallace ' s " ms, which he does not say he wishes me to publish ". then, a week later, he wrote to l


wallace ' s paper arrived, darwin wrote an anguished letter to lyell, in which he refers to wallace ' s " ms, which he does not say he wishes me to publish ". then, a week later, he wrote to lyell again, to express his misgivings about lyell ' s and hooker ' s plan. one of his reasons for worrying was that " wallace says nothing about publication ". why should such distinguished writers as ruse and mayr make this particular mistake? this is the kind of error that might perhaps follow from a moral presumption. it seems wrong to publish someone ' s work, without consulting him, in a forum he has not approved. thus, if we are assuming that darwin and his friends acted properly, it will be natural to assume that wallace must have asked that his paper be published. but in fact he did not... - - james rachels, summer 1986. national forum 66 ( 3 ) : 24. the concept of r - and k - selection is intuitively reasonable and indeed there is much circumstantial evidence from both macroecology and microbial ecology that it exists. the seminal ideas were contributed largely by dobzhansky ( 1950 ), who compared evolution in the tropics and temperate latitudes. actually, it is usually overlooked that the great naturalist wallace ( 1878 ), in his remarks on tropical plant and animal life, anticipated many of dobzhansky ' s conclusions. dobzhansky surmised that adaptation in the species - rich tropics is primarily to a harsh biological environment, while the fewer species in colder realms have to contend mainly with the physical environment. put simplistically, the outcome of different evolutionary pressures between the two regions is competitiveness ( high k ) or productivity ( high r ), respectively... - - john h. andrews & robin f. harris, 1986. advances in microbial ecology 9 : 104.... there even continued to be one or two plebeians who became recognised leaders in a field. most famously, though a. r. wallace... was of impoverished gentle family, he had something of a craftsmanly formation, during which he became a life - long owenite ( he died in 1913 ). had his fellow - frss borne this in mind, they might have been less puzzled by his left - wing politics, his anti - vaccinationism and his plebeian - type spiritualism. a


( he died in 1913 ). had his fellow - frss borne this in mind, they might have been less puzzled by his left - wing politics, his anti - vaccinationism and his plebeian - type spiritualism. a recent historian has plausibly treated him as an import into the later nineteenth century from the 1840s, and we might also see him as an import into prestigious scientific circles from the world of self - taught scientists. his particular route to eminence involved much specimen - hunting but no diploma - hunting, much jungle - fever but no exam - fever... - - logie barrow, 1986. in his independent spirits ; spiritualism and english plebeians, 1850 - 1910 ( routledge & kegan paul ) : 153.... darwin and wallace defended a programme of theoretical research by appeal to the superior coherence and fecundity of their programme. the appeal to superior coherence took place on two levels. at a substantive level they argued that their programme promised the discovery of relevantly similar natural forces for the explanation of relevantly similar natural phenomena. at an epistemic level they claimed coherence in their use of biogeographical and geological evidence and coherence in the application of the epistemic desideratum of scrutability. as wallace had suggested, the appeal to coherence at substantive and epistemic levels is justified by the overall aim of science to construe its subject matter as maximally accessible to investigation and as maximally decidable by acceptable argument. the appeal to superior fecundity can also be justified as instrumental to the achievement of these aims... - - scott a. kleiner, december 1985. british journal for the philosophy of science 36 ( 4 ) : 391. the allopatric model of speciation proposes that populations diverge genetically during a period of isolation either by drift, differential selection or different responses to similar selection pressures. when the barrier to dispersal is removed, this divergence may have led to premating reproductive isolation, post - mating isolation or both. only if there is complete assortative mating, hybrid inviability or hybrid infertility will the two new taxa be able to coexist without exchanging genes and only if there is at least some premating reproductive isolation will they be able to invade on another ' s territory. otherwise a hybrid zone is expected to form. premating isolation may evolve, or be strengthened, in the hybrid zone because het