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Silver-level articleNon-Darwinian evolution

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Non-Darwinian evolution is any mechanism which tends to downplay the role of natural selection in evolution. It also may reject gradualism, sexual selection or any other aspect of Darwinian evolution.

It should be remembered that "alternative medicine" which actually works is called "medicine". The same care needs to be taken with "Non-Darwinian evolution" — if it were generally accepted it would be part of the Modern Synthesis.

Contents

[edit] Introduction

Historian of science Peter J. Bowler has written on non-Darwinian evolution in detail. According to Bowler, non-Darwinian theories of evolution were widely accepted in the late 19th century and focused attention on conceptual issues that have now been reopened by evolutionary developmental biology. Non-Darwinian evolution was proposed because many scientists did not believe natural selection was powerful enough to explain evolution.[1]

Bowler, who has written The Eclipse of Darwinism: anti-Darwinian evolutionary theories in the decades around 1900 (1983), has described a period called the eclipse of Darwinism which discusses the state of affairs prior to the neo-Darwinian synthesis, when evolution was widely accepted in scientific circles, but relatively few biologists believed that natural selection was its primary mechanism. Instead of natural selection, scientists in this period were advocating other non-Darwinian mechanisms, such as orthogenesis, neo-Lamarckism, vitalism, or saltationism. Most scientists of this period did not deny natural selection, they just said it either has no role in evolution or only has a minor role as a mechanism.

Some of the non-Darwinian theories of the later 19th century, such as theistic evolution and orthogenesis, were often progressionist and implicitly teleological: they assumed that evolution was intended to develop toward a directed path or trend.[2]

The non-Darwinian alternative mechanisms, such as saltationism and neo-Lamarckism, had a significant following well into the 20th century and it wasn't until developments in genetics made some of them less popular. They were largely abandoned when population genetics and the modern evolutionary synthesis demonstrated the explanatory power of natural selection. Ernst Mayr[wp] wrote that as late as 1930, most textbooks still emphasized non-Darwinian mechanisms of evolution.[3]

[edit] Definition

Non-Darwinian evolution does not deny or dispute common descent or the fact of evolution. It is only concerned with denying or downplaying the "Darwinian" mechanisms of evolution, such as natural selection or sexual selection. In the early 1900s, there was a near-universal tendency to accept evolution while rejecting Darwin's central premise: natural selection. Genetic engineering may place the selection power in the boardroom, as in the case of the designer organisms proposed by transhumanists. Most non-Darwinian evolutionary mechanisms also deny gradualism.

All genetic mechanisms, such as gene flow, mutation, genetic drift or genetic hitchhiking could be considered "non-Darwinian", because Charles Darwin did not know about genetics. However, scientists who advocate the neo-Darwinian synthesis have reconciled all of these genetic mechanisms with natural selection within a Darwinian framework. Non-Darwinian evolution is in opposition to the neo-Darwinian synthesis, which ascribes a central role to natural selection. Non-Darwinian evolutionary scientists such as (Shapiro, 2011) deny that genetic mechanisms can fit into a Darwinian framework (see below).

[edit] Macroevolution and speciation

In the "modern synthesis" of neo-Darwinism, which developed in the period from 1930 to 1950 as a result of reconciliation of evolution by natural selection with genetics, macroevolution is defined as the combined effects of microevolutionary processes. Non-Darwinians, who proposed orthogenetic mechanisms, claimed that macroevolution is a different process than microevolution. According to biologist John Wilkins, nobody has been able to make a good case for orthogenesis since the 1950s. Wilkins also wrote that "Non-Darwinian evolutionists think that the processes that cause speciation are of a different kind to those that occur within species. That is, they admit that macroevolution occurs, but think that normal genetic change is restricted by such proposed mechanisms as developmental constraints. This view is associated with the names of Schmalhausen[wp] and Waddington, who were often characterised as being non-Darwinians by the modern synthesis theorists."[4]

[edit] Mechanisms

The most well known non-Darwinian mechanisms include:[5]

  • Orthogenesis — the view that evolution proceeds along predetermined paths rather than through selection from a pool of random change, also sometimes called teleological evolution or progressionism
  • Neo-Lamarckism — the view that the environment instructs the genome, and/or the view that changes occur to anticipate the needs of the organism
  • Process Structuralism — the view that there are deep laws of change that determine some or all of the features of organisms
  • Saltationism — the view that major changes between forms occur all-at-once or not at all, opposes Darwinian gradualism

American biologist James A. Shapiro described the following non-Darwinian mechanisms.[6]

  • William Bateson[wp] (1861-1926) and Hugo de Vries[wp] (1848-1935): abrupt variation as a source of evolutionary novelty.
  • Richard Goldschmidt (1878-1958): altering developmental processes as a source of rapid evolutionary novelty (“hopeful monsters” and Evo-Devo).
  • Barbara McClintock[wp] (1902-1992): genetic change as a biological response to danger and evolutionary novelty through genome restructuring resulting from "shocks".
  • G. Ledyard Stebbins[wp] (1906-2000): hybridization between species as a source of evolutionary novelty.
  • Carl Woese[wp] (1928-2012): molecular phylogeny and the existence of at least three distinct cell kingdoms.
  • Lynn Margulis[wp] (1938-2011): cell mergers/symbiogenesis as a source of evolutionary novelty.

[edit] Orthogenesis

Orthogenesis, also known as directed evolution, is the hypothesis that evolution has an innate tendency to evolve in a unilinear fashion due to some internal or external force or mechanism. Various theories of orthogenesis were presented in the 20th century by many scientists such as apogenesis (Hans Przibram), allelogenesis (Alphonse Labbé), bathmism (Edward Drinker Cope) nomogenesis (Lev Berg), aristogenesis (Henry Fairfield Osbourn), hologenesis (Daniel Rosa), Omega Point (Pierre Teilhard de Chardin) and typostrophism (Otto Schindewolf).[7]

The theories of orthogenesis ranged from mystical forces to mechanical processes. Most however who subscribed to orthogenesis hypothesized some physical rather than metaphysical determinant of orderly change. In 1930 the American zoologist Austin Hobart Clark attempted to modify orthogenesis with his theory of zoogenesis.

The orthogenesis hypothesis began to collapse after it was discovered it could not explain some of the patterns found by paleontologists in the fossil record, which were non-linear with many complications. Orthogenesis was abandoned by most scientists due to the discovery of genetic mechanisms of evolution in the 20th century.[8]

[edit] Current status

Orthogenesis is considered obsolete by most scientists since the 1950s. Antonio Lima-de-Faria a cytogeneticist has recently defended a form of directed evolution in his publications writing that evolution is "ordered" by physico-chemical processes and that natural selection has nothing to do with evolution.[9] His views have been criticised by other scientists.[10]

[edit] Neo-Lamarckism

The term neo-Lamarckism refers to a loose grouping of largely heterodox theories and mechanisms that emerged after Lamarck's time which support the inheritance of acquired characteristics (physiological changes acquired over the life of an organism transmitted to offspring).

According to Peter J. Bowler:

One of the most emotionally compelling arguments used by the neo-Lamarckians of the late nineteenth century was the claim that Darwinism was a mechanistic theory which reduced living things to puppets driven by heredity. The selection theory made life into a game of Russian roulette, where life or death was predetermined by the genes one inherited. The individual could do nothing to mitigate bad heredity. Lamarckism, in contrast, allowed the individual to choose a new habit when faced with an environmental challenge and shape the whole future course of evolution.[11]

Lamarckian evolution fell into decline due to the experimental work of the German biologist August Weismann, which resulted in the germplasm theory of inheritance, according to which (in a multicellular organism) inheritance only takes place by means of the germ cells—the gametes such as egg cells and sperm cells. Other cells of the body—somatic cells—do not function as agents of heredity. The effect is one-way: germ cells produce somatic cells and are not affected by anything the somatic cells learn or therefore any ability the body acquires during its life. Genetic information cannot pass from soma to the germplasm and on to the next generation. This is referred to as the Weismann barrier and if true, rules out the inheritance of acquired characteristics as proposed by Lamarck.

The ideas of Weismann were believed to be true by many scientists. One of his experiments involved cutting the tails off many generations of mice and found that their offspring continued to develop tails. Despite these criticisms, neo-Lamarckism remained the most popular alternative to natural selection at the end of the 19th century, and would remain the position of some naturalists in the 20th century. Due to the rise of Mendelian genetics in 20th century the possibility of acquired characteristics was denied by the neo-Darwinian synthesis.

The paleontologist Edward Drinker Cope (1840–1897) was the main advocate of neo-lamarckism in America. Other notable supporters included Samuel Butler (1835-1902), George Bernard Shaw (1856-1950) and Arthur Koestler (1905-1983). Neo-Lamarckism remained popular in France as late as the 1980s due to scientists such as Albert Vandel (1894-1980) and Pierre-Paul Grassé (1895-1985).[12]

[edit] Current status

Despite the abandonment by most scientists, interest in Lamarckism has recently increased due to discoveries and studies in epigenetics.[13] In MIT's Technology Review in February 2009, it was written "The effects of an animal's environment during adolescence can be passed down to future offspring ... The findings provide support for a 200-year-old theory of evolution that has been largely dismissed: Lamarckian evolution, which states that acquired characteristics can be passed on to offspring."[14]

[edit] Process Structuralism

Brian Goodwin.

Process structuralism is a school of biological thought that deals with the law-like behaviour of the structure of organisms and how it can change. Structuralists tend to emphasise that organisms are wholes, and that change in one part must necessarily take into account the inter-connected nature of the entire organism.[15] An early advocate of structuralism was D'Arcy Wentworth Thompson author of On Growth and Form (1917).

On the subject of process structuralism (Griffiths, 2006) has written "[Structuralists] downplay the role of natural selection in explaining the diversity of life. They interpret evolutionary history as an exploration of possibilities implicit in the conditions that set up the evolutionary process. According to process structuralists... the space of possible biological forms ('morphospace') is divided into regions characterized by particular 'generic forms'. From a Darwinian perspective, generic forms appear as traits that are highly conserved in certain lineages. According to process structuralism, generic forms result from the fundamental ways in which organisms in those lineages grow."[16] In process structuralism genes cannot fully explain the complexity of biological systems.

According to the process structuralist critique of neo-Darwinism:[17]

  1. There are general laws in biology and that biologists should search for these laws.
  2. There are general forms of morphology and development and that biologists should attempt to uncover these forms.
  3. Organisms are unified wholes that cannot be understood without adopting a holistic perspective.
  4. No special, causal primacy should be given to the genes in development and morphology.

The research of the Canadian biologist Brian Goodwin (1931-2009) is known for having laid the foundations for the process structuralist movement in biology.[18]

[edit] Current status

Process structuralism is not a mainstream school of biological thought and has been criticised by some scientists, however some biological structuralist ideas have been taken up by evolutionary developmental biology.

[edit] Saltationism

Thomas Henry Huxley.

Saltationism is defined as a sudden change from one generation to the next, that is large, or very large, in comparison with the usual variation of an organism. Saltational evolution is non-gradual and violates the standard concepts of gradualism in evolution.

Prior to Charles Darwin virtually all evolutionary scientists had been saltationists.[19] With the publication of On Origin of Species in 1859 Darwin had denied saltational evolution by writing that evolutionary transformation always proceeds gradually and never in jumps. Darwin insisted on slow accumulation of small steps in evolution and wrote "natural selection acts solely by accumulating slight successive favourable variations, it can produce no great or sudden modification; it can act only by very short steps".[20] Darwin had a strong belief in gradualism due to his observations on the Galápagos Mockingbird which were best explained by gradual evolution. Darwin was also influenced by Charles Lyell's uniformitarianism.

Darwin's friend Thomas Henry Huxley felt that evolution could be either gradual or saltational. In his review of the Origin he wrote:

Mr. Darwin's position might, we think, have been even stronger than it is if he had not embarrassed himself with the aphorism, "Natura non facit saltum," which turns up so often in his pages. We believe, as we have said above, that Nature does make jumps now and then, and a recognition of the fact is of no small importance in disposing of many minor objections to the doctrine of transmutation.[21]

Other scientists of this era similar to Huxley also held the view that evolution could be both gradual or saltational. It wasn't until the discovery of genetics in the 1890s that saltationism came to be known as the idea that new species arise as a result of large mutations. It was seen as faster alternative to the Darwinian concept of a gradual process of small random variations being acted on by natural selection. The view was popular with early geneticists such as William Bateson,[wp] Hugo De Vries[wp] and Thomas Hunt Morgan.[22] This mutation theory of evolution held that species went through periods of rapid mutation, possibly as a result of environmental stress, that could produce multiple mutations, and in some cases completely new species, in a single generation. This mutationist view of evolution was later replaced by the reconciliation of Mendelian genetics with natural selection into a gradualistic framework for the neo-Darwinian synthesis.[23]

It was the emergence of population thinking in evolution which forced many scientists to adopt gradualism in the early 20th century. According to Ernst Mayr, it wasn't until the development of population genetics in the neo-Darwinian synthesis in the 1940s that demonstrated the explanatory power of natural selection that saltational views of evolution were largely abandoned.[24]

Some of the last supporters of saltational evolution by large mutations were Richard Goldschmidt, who is most well known for his hypothesis of hopeful monsters, Otto Schindewolf and J. C. Willis.

[edit] Current status

Exceptions to gradualism include cases of stabilized hybrids that can reproduce without crossing (such as allotetraploids) and cases of symbiogenesis.[wp] Polyploidy (most common in plants but also in some animals) is also considered a type of saltation. Evidence of phenotypic saltation has been found in the centipede[25] and some scientists have suggested there is evidence for independent instances of saltational evolution in Sphinx Moths.[26] Some processes of epigenetic inheritance can also produce changes that are saltational.[27] There has been a controversy over if mimicry in butterflies and other insects can be explained by gradual or saltational evolution.[28] According to (Norrstrom et al. 2007) there is evidence for saltation in some cases of mimicry.[29]

Eugene K. Balon has recently advocated some controversial mechanisms of saltation due to his research in ichthyology but have been criticised by some scientists.

[edit] Controversies

[edit] Punctuated equilibrium

Punctuated equilibrium is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in stasis. Whilst significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and geologically rapid events of branching speciation. It is commonly contrasted against the theory of phyletic gradualism. Paleotonologists such as Stephen Jay Gould, Niles Eldredge and Steven M. Stanley have advocated punctuated equilibrium and have explained how it is still compatible with the neo-Darwinian synthesis via an extension. Gould, Eldredge and Stanley have all called for an extended evolutionary synthesis. Creationists usually claim that Gould, Eldredge and Stanley are "anti-Darwinians," but this is not true since they all accepted natural selection.

The biologist Soren Lovtrup wrote that punctuated equilibrium is not a non-Darwinian theory as it can still be classified as a form of gradualism.[30] Punctuated equilibrium should not be confused with saltationism.

[edit] Directed mutation

Directed mutation is the hypothesis that organisms can respond to environmental stresses through directing mutations to certain genes or areas of the genome. Most experiments have proven mutations are random, so the idea of directed mutation is rejected by many scientists. There is still a controversy over the work of John Cairns on supposed evidence for directed mutation in bacteria which he later termed "adaptive evolution" which some scientists have rejected, instead proposing his results can be explained by Darwinian processes.

[edit] Extinctions

In the classical Darwinian view of evolution, extinctions are seen as the consequence of natural selection. David Raup, author of Extinction. Bad Genes or Bad Luck? (1991), does not deny that some species go extinct this way but has written that the majority of extinctions especially mass extinctions are caused by physical factors such as comets, climatic changes and catastrophes. David Jablonski[wp] and Steven M. Stanley have also written on extinctions and advocated similar views to Raup.

Raup is not challenging natural selection as a cause of modification of species he just claimed that gradual change by natural selection is not the only mechanism of evolution as non-gradual extinction events also have a role.[31] Creationists however usually quote mine Raup to make out he is denying natural selection.

[edit] Mae-Wan Ho

Mae-Wan Ho is a geneticist who has become well known for her criticism of the modern synthesis. Since the 1980s she has written in publications that a paradigm shift has occurred in evolution due to discoveries in epigenetics which have disproven and replaced many of the tenents of neo-Darwinism.[32] In 1984 she published with other scientists a book titled published Beyond Neo-Darwinism: An Introduction to the New Evolutionary Paradigm. The book received a mixed response from the scientific community but was strongly criticised by some scientists.

[edit] Elisabet Sahtouris

Elisabet Sahtouris, an evolutionary biologist, has opposed neo-Darwinism for its reductionistic gene centric view of organisms. According to Sahtouris organisms should be viewed as living systems and not just based on their genes. Her book Biology Revisioned (1998) advocates a form of "holistic biology" with consciousness and self-organizational factors having a role in the evolutionary process. Similar to Mae-Wan Ho her views have been criticised by some scientists. The general criticism of Sahtouris is that she is mixing science with new age themes.

[edit] Shapiro and non-Darwinian mechanisms

American biologist James A. Shapiro in his book Evolution: A View from the 21st Century (2011) has written that evolutionary mechanisms such as Horizontal gene transfer,[wp] symbiogenesis, whole genome doubling[wp] and natural genetic engineering[wp] are all non-Darwinian and can not be fitted into the modern evolutionary synthesis, as the modern synthesis is still working within a Darwinian framework. Shapiro believes many of these mechanisms fit better with a saltationist school rather than Darwin's strict advocacy of gradualism via "numerous, successive, slight variations". Shapiro also claims that natural selection's importance for evolution has been hugely overstated.[33]

Jerry Coyne a professor of biology and critic of non-Darwinian evolution has denied these claims of Shapiro and has said all of the genetic mechanisms Shapiro discusses still fit into the Darwinian gradual framework of the modern synthesis and do not downgrade the efficacy of natural selection.[34]

On the subject of Shapiro and the role of natural selection in evolution, evolutionary biologist Adam S. Wilkins has written:

My impression is that evolutionary biology is increasingly separating into two camps, divided over just this question. On the one hand are the population geneticists and evolutionary biologists who continue to believe that selection has a “creative” and crucial role in evolution, and on the other, there is a growing body of scientists (largely those who have come into evolution from molecular biology, developmental biology or developmental genetics, and microbiology) who reject it. In contrast to Victorian scientists who regarded Darwinian natural selection as “incapable” of creating high degrees of biological complexity, the modern sceptics tend to regard it as of “trivial” importance: the “right” variant for the right place and time arises and, presto, the population changes! The two contemporary groups, divided over this point, are not so much talking past each another as ignoring one another.[35]

Wilkins also wrote that arguments from paleontology have shown the importance of natural selection in long-term trends of morphological change and that non-Darwinian evolutionary scientists who play down natural selection have not yet explained which mechanism is responsible for such trends apart from orthogenesis which is considered obsolete by most scientists. Creationists usually quote mine and misunderstand the work of Shapiro in an attempt to make out evolution is falling apart however as scientists have pointed out Shapiro is not questioning the fact of evolution, he is only questioning the role of natural selection in evolution which is perfectly valid science, "and will either stand the test of time, and questioning by other scientists, or it will fall".[36]

There has also been a controversy over natural genetic engineering (NGE), a process described by Shapiro to account for novelty created in the process of biological evolution. Shapiro developed NGE in peer-reviewed publications and later in his book Evolution: A View from the 21st Century. NGE has become controversial, as it rejects the neo-Darwinian synthesis and the central dogma of molecular biology.[wp] It has been widely reviewed by the scientific community and criticised by some scientists.

Shapiro's ideas on natural genetic engineering have been quote mined by creationists, even though he has explicitly and repeatedly rejected creationism and intelligent design.

[edit] Eugene Koonin

Molecular biologist Eugene Koonin has written in his publications that the neo-Darwinian concepts of biological evolution are considered outdated due to recent discoveries in comparative genomics and systems biology.[wp] In his book The Logic of Chance: The Nature and Origin of Biological Evolution (2011) Koonin wrote:

The exclusive focus of Modern Synthesis on natural selection acting on random genetic variation has been replaced with a plurality of complementary, fundamental evolutionary processes and patterns. In the new evolutionary biology, natural selection is but one of the processes that shape evolving genomes—and, apparently, not the quantitatively dominant one. To a large extent, neutral processes such as genetic drift and draft define evolution.[37]

Koonin has called for a paradigm shift in evolutionary biology which he believes has replaced many parts of the neo-Darwinian synthesis. He has written for example "In the post-genomic era, all the major tenets of the modern synthesis have been, if not outright overturned, replaced by a new and incomparably more complex vision of the key aspects of evolution".[38] He also wrote a paper in 2009 titled Is evolution Darwinian or/and Lamarckian? in which he claimed certain evolutionary mechanisms fit the criteria as evidence for Lamarckian inheritance and came to the conclusion that both "Darwinian and Lamarckian modalities of evolution appear to be important, and reflect different aspects of the interaction between populations and the environment."[39]

[edit] Extended Synthesis

Over the past decade, new conceptions of evolutionary theory have emerged going under the umbrella term of the "Extended Synthesis," which is intended to modify the existing Modern Synthesis. This proposed extended synthesis incorporates new possibilities for integration and expansion in evolutionary theory, such as Evo-devo, epigenetic inheritance[wp] and niche construction.[wp] Its proponents include Massimo Pigliucci, Gerd B. Müller,[wp] and Eva Jablonka.[40] In 2008 sixteen scientists met at the Konrad Lorenz Institute in Altenberg, Austria to propose an extended synthesis. Creationists and intelligent design advocates have misunderstood and distorted the events of this meeting (see Altenberg 16 controversy) by claiming the scientists involved with the extended synthesis are "anti-Darwinian". Massimo Pigliucci has explained that the extended synthesis is not "anti-Darwinian" (Pigliucci and Müller, 2010). Whilst the extended synthesis does advocate some "non-Darwinian" mechanisms such as epigenetic inheritance or niche construction it does not reject Darwinian natural selection and should not be confused with non-Darwinian evolution.

[edit] Neutral evolution

The neutral theory of molecular evolution claims that most allelic variation and substitutions in proteins and DNA are neutral. Neutral evolution has been called a non-Darwinian evolution, as most substitutions are caused via genetic drift rather than natural selection.[41] A paper was written on the subject in 1969 called Non-Darwinian evolution by Jack Lester King and Thomas H. Jukes[wp]. Neutral theory was first developed by Motoo Kimura[42] and his student Tomoko Ohta.[43]

[edit] Non-Darwinian selection

Jan Smuts.

Non-Darwinian selection refers to changes in populations produced by selection processes other than natural selection.[44]

[edit] Holistic selection

Jan Smuts developed a non-Darwinian form of internal selection in his book Holism and Evolution (1926):

[Holistic Selection] acts within each organism in respect of its parts inter se is essentially different from the Natural Selection which operates between different organisms, which is more appropriately called the struggle for existence. Holistic Selection is much more subtle in its operation, and is much more social and friendly in its activity ; it puts the inner resources of the organism behind the promising variation, however weak and feeble it may be in comparison with other characters, and makes it win through powerful backing rather than through the ruthless scrapping of the less desirable variations. In the organism the battle is not always to the strong, nor is the struggle an unregulated scrimmage in which the most virile survive. The whole is all the time on the scene as an active friendly arbiter and regulator, and its favours go to those variations which are along the road of its own development, efficiency and perfection.[45]

[edit] Teleonomic selection

Peter Corning has coined the term "teleonomic selection" to describe purposive behavior playing an important causal role in initiating evolutionary changes. He described this selection theory as "living beings that do the selecting... a "purposeful process" that is intimately related to meeting basic survival reproductive needs in a given context." Corning does not reject natural selection and has written that teleonomic selection works with it to affect evolutionary change.[46]

Corning later termed his theory of teleonomic selection as "neo-Lamarckian selection". According to Corning:

At the behavioral level... there is a proximate selective process at work that is analogous to natural selection. I call it Neo-Lamarckian Selection. Moreover, this “mechanism” is very frequently the initiating cause of the ultimate changes associated with natural selection... One example of this “mechanism” is the evolution of giraffes, which are frequently cited in elementary biology textbooks as an illustration of the distinction between Lamarckian and Darwinian evolution. Evolutionists like to point out that the long necks of modern giraffes are not the product of stretching behaviors that were somehow incorporated into the genes of their short-necked ancestors (as Lamarck supposed). Instead, natural selection favored longer-necked giraffes once they had adopted the “habit”of eating tree leaves. And that is the point. A change in the organism-environment relationship among ancestral giraffes, occasioned by the adoption of a novel behavior, precipitated a new “selection pressure” for morphological change. (So Lamarck was half right.)[47]

[edit] Social selection

Evolutionary biologist Joan Roughgarden has presented a theory termed "social selection" as an alternative to sexual selection. Roughgarden has criticised sexual selection in her publications as she believes it has been contradicted by various sexual behaviours in the animal kingdom and has written it fails to explain the homosexuality that has been documented in over 450 different vertebrate species.[48] Many scientists have rejected the claims of Roughgarden.

[edit] Spiritual evolution

For the main article on this topic, please see Spiritual evolution.

Most non-Darwinian evolutionary mechanisms that have been presented have been natural, however some scientists and writers have advocated theistic or spiritual evolutionary mechanisms. Alfred Russel Wallace and the biologist St. George Jackson Mivart were two early scientists to invoke supernatural factors in evolution.

Regarding the evolutionary ideas of Wallace and Mivart, Thomas Henry Huxley wrote:

Wallace and Mr. Mivart... are as stout believers in evolution as Mr. Darwin himself; but Mr. Wallace denies that man can have been evolved from a lower animal by that process of natural selection which he, with Mr. Darwin, holds to have been sufficient for the evolution of all animals below man; while Mr. Mivart, admitting that natural selection has been one of the conditions of the evolution of the animals below man, maintains that natural selection must, even in their case, have been supplemented by "some other cause"–of the nature of which, unfortunately, he does not give us any idea. Thus Mr. Mivart is less of a Darwinian than Mr. Wallace, for he has less faith in the power of natural selection. But he is more of an evolutionist than Mr. Wallace, because Mr. Wallace thinks it necessary to call in an intelligent agent–a sort of supernatural Sir John Sebright–to produce even the animal frame of man; while Mr. Mivart requires no Divine assistance till he comes to man's soul.[49]

Similar ideas later appear in the writings of Teilhard de Chardin.[wp]

Oliver L. Reiser believed that evolution was driven by geomagnetic forces. He claimed that there was a "memory field" around the Earth, which he called the "psychosphere", which influenced evolution.

[edit] Vitalism

In the late 19th century, scientists who supported vitalism thought Darwin's theories were too materialistic to explain the complexity of life and proposed mechanisms of vital or psychic evolution. Wilhelm Wundt, August Pauly, Eduard von Hartmann, Hans Dreisch and Eric Wasmann abandoned natural selection for internal, vital principles of psychic evolution.[50]

The biologist Hans Driesch (1867-1941) held that both Darwinian and Lamarckian evolutionary mechanisms were unable to explain evolution adequately. This according to Dreisch was because natural selection was a negative principle, which could explain the elimination of particular forms, but not the creation of new diversities. Instead Driesch proposed that living organisms were driven by a vital principle, a nonmechanical "life force" which he proposed to represent by Aristotle's term "entelechy".

By the 1930s, vitalism had fallen out of favour. On discussing the history of vitalism in biology, Ernst Mayr wrote in 1988: "Vitalism has become so disreputable a belief in the last fifty years that no biologist alive today would want to be classified as a vitalist. Still, the remnants of vitalist thinking can be found in the work of Alistair Hardy, Sewall Wright, and Charles Birch, who seem to believe in some sort of nonmaterial principle in organisms."[51]

In recent years, some non-scientists and new age writers have defended forms of vitalism, such as arguments for the existence of an immaterial "life force" directing evolution. Such views, however, have been deemed pseudoscience by the scientific community.

[edit] Non-Darwinian evolution and creationism

Unfortunately, most religious creationists and intelligent design advocates usually equate evolution with "Darwinism" and it is clear many of these authors out of dishonesty do this on purpose. Where it is clear non-Darwinian scientists or writers are only debating the role of natural selection in evolution and the mechanisms which brought evolution about, creationists often quote mine and distort quotes from these scientists in an attempt to create the impression that these scientists were actually denying evolution.

In 2011, biologist A. L. Hughes published a paper titled Evolution of adaptive phenotypic traits without positive Darwinian selection, in which he proposed a non-Darwinian mechanism of adaptation which he termed "plasticity–relaxation–mutation" (PRM).[52] The paper has been misunderstood and quote mined by creationists to suggest that evolution is falling apart.[53]

Intelligent design writer Jean Staune has written a paper on non-Darwinian evolution and has listed Michael Denton and Michael Behe as "non-Darwinian evolutionists", since they accept common descent. Staune claims the way forward for the ID movement is for IDers to accept common descent, but to propose non-Darwinian mechanisms to downplay or replace natural selection. However, it is clear from Staun's paper that he has no interest in proposing any natural mechanisms for evolution and is only interested in metaphysical speculation.[54]

Creationists have also incorrectly described punctuated equilibrium (PE) as "non-Darwinian". Richard Dawkins declared that "[PE] lies firmly within the neo-Darwinian synthesis” in his book The Blind Watchmaker.

[edit] External links

[edit] Further reading

  • Peter Bowler Evolution: The History of an Idea (2009) ISBN 978-0520261280
  • Thomas Glick The Comparative Reception of Darwinism (1988) ISBN 978-0226299778
  • James Moore The Post-Darwinian Controversies: A Study of the Protestant Struggle to Come to Terms with Darwin in Great Britain and America, 1870-1900 (1981) ISBN 978-0521285179
  • Nicolaas Rupke Richard Owen: Biology without Darwin (2009) ISBN 978-0226731773
  • Peter Vorzimmer Charles Darwin: The Years of Controversy: The Origin of Species and its critics, 1859-1882 (1970) ISBN 978-0877220015

[edit] Footnotes

  1. Do we need a non-Darwinian industry? by Peter J. Bowler
  2. Peter Bowler Evolution: The History of an Idea 1989 p. 24
  3. Mayr, Ernst; Provine, W. B., eds. (1998). The Evolutionary Synthesis: Perspectives on the Unification of Biology. Harvard University Press.
  4. Macroevolution FAQ, also see Link "A few non-Darwinian evolutionists remained, however, including Schmalhausen and Waddington, who argued that the processes of macroevolution are different from those of microevolution. According to these scientists, macroevolution occurs, but is restricted by such proposed mechanisms as developmental constraints. The concept can be summarized in: "Schmalhausen's Law," which holds that "When organisms are living within their normal range of environment, perturbations in the conditions of life and most genetic differences between individuals have little or no effect on their manifest physiology and development, but that under severe and unusual general stress conditions even small environmental and genetic differences have major effects." Non-Darwinian evolution points to evidence of great changes in population under conditions of stress; however, it is generally rejected by the scientific community because it provides no mechanism for larger changes at a genetic level under those circumstances."
  5. So You Want to be an Anti-Darwinian. Varieties of Opposition to Darwinism by John Wilkins
  6. Revisiting Evolution in the 21st Century by James A. Shapiro
  7. The Persistence of Heresy: The Concepts of Directed Evolution (Orthogenesis) by Igor Popov
  8. Bowler, Peter J. (1983). The Eclipse of Darwinism: anti-Darwinian evolutionary theories in the decades around 1900. Johns Hopkins University Press.
  9. The Problem of Constraints on Variation, From Darwin to the Present
  10. Evolution without Selection: Form and Function by Autoevolution a review by Gert Korthof
  11. Bowler, Peter J. (2003). Evolution: The History of an Idea. University of California Press p. 367
  12. French roots of French neo-lamarckisms, 1879-1985
  13. Early 20th Century Evolutionist May Have Discovered Epigenetics
  14. A Comeback for Lamarckian Evolution?
  15. Brian Goodwin, ”Beyond the Darwinian Paradigm: Understanding Biological Forms,” in Evolution: The First Four Billion Years, eds. Michael Ruse and Joseph Travis (Harvard University Press, 2009)
  16. Darwinism, Process Structuralism, and Natural Kinds by Paul E. Griffiths
  17. The rebirth of rational morphology by David Resnik
  18. Tribute to Brian Goodwin 1931-2009
  19. Osborn, H. F. 1894. From the Greeks to Darwin: An outline of the development of the evolution idea. New York, London, Macmillan and Co.
  20. Origin, P. 471
  21. Huxley, T. H. 1860. The origin of species. Westminster Review, 17: 541-570
  22. Bowler, Peter J. (1983). The Eclipse of Darwinism: anti-Darwinian evolutionary theories in the decades around 1900. Johns Hopkins University Press.
  23. Bowler, Peter J. (2003). Evolution:The History of an Idea. University of California Press.
  24. Ernst Mayr What Makes Biology Unique?: Considerations on the Autonomy of a Scientific Discipline Cambridge University Press; 1 edition 2007
  25. Saltational evolution of trunk segment number in centipedes
  26. Evidence of Repeated and Independent Saltational Evolution in a Peculiar Genus of Sphinx Moths (Proserpinus: Sphingidae)
  27. Epigenetic inheritance and plasticity: The responsive germline
  28. Mimicry, Saltational Evolution, and the Crossing of Fitness Valleys
  29. Coevolution of exploiter specialization and victim mimicry can be cyclic and saltational
  30. Review of Lovtrup's book in the New Scientist, Oct 15, 1988
  31. The Role of Extinction in Evolution by David M. Raup
  32. A New Paradigm for Evolution by Mae-Wan Ho
  33. James A. Shapiro Evolution: A View from the 21st Century ISBN 0132780933
  34. [1]
  35. Review by Adam S. Wilkins
  36. Doubt and dogmatism in science -- questioning natural selection
  37. Eugene Koonin. (2011). The Logic of Chance: The Nature and Origin of Biological Evolution. FT Press. p. 400
  38. Eugene Koonin, The Origin at 150: Is a new evolutionary synthesis in sight?" Trends in Genetics, 25(11), November 2009, pp. 473-475 Online and Eugene Koonin, Darwinian evolution in the light of genomics, Nucleic Acids Research, 37(4), 2009, pp. 1011-1034 Online
  39. Is evolution Darwinian or/and Lamarckian? by Eugene V. Koonin and Yuri I. Wolf
  40. Massimo Pigliucci. An Extended Synthesis for Evolutionary Biology. The Year in Evolutionary Biology 2009: Ann. N.Y. Acad. Sci. 1168: 218–228 (2009).
  41. John H. Gillespie Population Genetics: A Concise Guide, 2004
  42. Profiles: Motoo Kimura, History of Recent Science and Technology Project, California Institute of Technology Library
  43. Profiles: Tomoko Ohta, History of Recent Science and Technology Project, California Institute of Technology Library
  44. Definition of non-Darwinian selection
  45. Jan Smuts Holism and Evolution 1926
  46. Peter Corning Nature's Magic: Synergy in Evolution and the Fate of Humankind 2003, p. 182
  47. Peter Corning Holistic Darwinism: Synergy, Cybernetics, and the Bioeconomics of Evolution 2005, p. 35
  48. Joan Roughgarden Evolution's Rainbow: Diversity, Gender and Sexuality in Nature and People. Paperback ed. Los Angeles: Univ. of California Press, 2004. ISBN 0-520-24073-1
  49. Mr Darwin's Critics by Thomas Henry Huxley
  50. Robert J. Richards Darwin and the Emergence of Evolutionary Theories of Mind and Behavior 1989, p. 523
  51. Ernst Mayr Toward a New Philosophy of Biology: Observations of an Evolutionist 1988, p. 13
  52. Evolution of adaptive phenotypic traits without positive Darwinian selection by A. L. Hughes
  53. Post on intelligent design blog, see also creationist website
  54. Darwinism Design and Purpose: A European Perspective by Jean Staune


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