Orthogenesis


Orthogenesis

Orthogenesis, orthogenetic evolution, progressive evolution or autogenesis, is the hypothesis that life has an innate tendency to evolve in a unilinear fashion due to some internal or external "driving force". The hypothesis is based on essentialism and cosmic teleology and proposes an intrinsic drive which slowly transforms species. George Gaylord Simpson (1953) in an attack on orthogenesis called this mechanism "the mysterious inner force".[1] Classic proponents of orthogenesis have rejected the theory of natural selection as the organising mechanism in evolution, and theories of speciation for a rectilinear model of guided evolution acting on discrete species with "essences". The term orthogenesis was popularized by Theodor Eimer, though many of the ideas are much older (Bateson 1909).[2]

Contents

Definition

Orthogenesis was a term first used by the biologist Wilhelm Haacke. Theodor Eimer was the first to give the word a definition, he defined orthogenesis as "the general law according to which evolutionary development takes place in a noticeable direction, above all in specialized groups."[3]

Orthogenesis was often related to Neo-Lamarckism; Eimer popularized the concept of orthogenesis in his book Organic Evolution as the Result of the Inheritance of Aquired Characteristics According to the Laws of Organic Growth (1890). In his work Eimer used examples such as the evolution of the horse to argue that evolution had proceeded in a regular single direction that was difficult to explain by random variation. To orthogenesis trends in evolution were often nonadaptive and in some cases species could be lead to extinction.[4]

Peter J. Bowler defines orthogenesis as:

Literally, the term means evolution in a straight line, generally assumed to be evolution that is held to a regular course by forces internal to the organism. Orthogenesis assumes that variation is not random but is directed towards fixed goals. Selection is thus powerless, and the species is carried automatically in the direction marked out by internal factors controlling variation.[5]

According to (Schrepfer, 1983):

Orthogenesis meant literally "straight origins", or "straight line evolution". The term varied in meaning from the overtly vitalistic and theological to the mechanical. It ranged from theories of mystical forces to mere descriptions of a general trend in development due to natural limitations of either the germinal material or the environment... By 1910, however most who subscribed to orthogenesis hypothesized some physical rather than metaphysical determinant of orderly change.[6]

Orthogenesis has been described as an "anti-Darwinian" evolutionary theory because of its stance on the Darwinian mechanism of natural selection.[7] After studying butterfly coloration Theodor Eimer published a widely read book on orthogenesis titled On Orthogenesis: And the Impotence of Natural Selection in Species Formation (1898). In the book Eimer claimed there were trends in evolution with no adaptive significance and thus would be difficult to explain by natural selection.[8] Stephen J. Gould wrote a detailed biography of Eimer. Gould wrote that Eimer was a materialist who rejected any vitalist or teleological approach to orthogenesis and explained that Eimer's criticism of natural selection was common amongst many evolutionists of his generation as they were searching for alternative evolutionary mechanisms as it was believed at the time that natural selection could not create new species.[9]

Origins

The orthogenesis hypothesis had a significant following in the 19th century when a number of evolutionary mechanisms, such as Lamarckism, were being proposed. Jean-Baptiste Lamarck himself accepted the idea, and it had a central role in his theory of inheritance of acquired characteristics, the hypothesized mechanism of which resembled the "mysterious inner force" of orthogenesis. Other proponents of orthogenesis included Leo S. Berg, philosopher Henri Bergson and, for a time, the paleontologist Henry Fairfield Osborn. Orthogenesis was particularly accepted by paleontologists who saw in their fossils a directional change, and in invertebrate paleontology thought there was a gradual and constant directional change. Those who accepted orthogenesis in this way, however, did not necessarily accept that the mechanism that drove orthogenesis was teleological. In fact, Darwin himself rarely used the term "evolution" now so commonly used to describe his theory, because in Darwin's time, evolution usually was associated with some sort of progressive process like orthogenesis, and this had been common usage since at least 1647.[10]

The zoologist Charles Otis Whitman did not believe in Lamarckism, Darwinism or mutationism, instead Whitman was an advocate of orthogenesis. Whitman only wrote one book on orthogenesis which was published nine years after his death in 1919 titled Orthogenetic evolution in pigeons the book was published in a three volume set titled Posthumous Works of Charles Otis Whitman.[11][12] Stephen Jay Gould wrote that the book was written "too late, to win any potential influence".[13]

In 1930 the American zoologist Austin Hobart Clark attempted to modify orthogenesis with his theory of zoogenesis.[14]

Comparison of Theories

Theories of Evolution
Comparison of different theories of evolution
  Darwinism Orthogenesis Lamarckism
Mechanism 1. Short-sighted Natural Selection sorting random genetic variation, no other guidance or aim.
2. Selected traits are adaptive, i.e. have some survival value.
1. Driven by some internal mechanism, but not towards a goal.
2. Natural selection unimportant.
3. Characters produced may be totally non-adaptive, i.e. have no survival value.
1. Intrinsic drive towards perfection
2. Inheritance of acquired characteristics (both are Lamarckian principles)
3. Natural selection adopted by some in latter years.
Common descent Yes
New species coming into existence by speciation events.
No
Speciation rejected or considered unimportant in long term trends; spontaneous generation of new species resulting in parallel evolution.
Depends upon source quoted
Signs that species shared a common ancestor were detected before Darwin, but in absence of a mechanism some still rejected the idea.
Status Prevailing in modified form as modern evolutionary synthesis. Refuted by Charles Darwin's Origin of Species and the modern evolutionary synthesis. Declined after the Origin, though the mechanism was not refuted until the modern evolutionary synthesis in which it was established that the mechanism does not exist.

Collapse of the hypothesis

The orthogenesis hypothesis began to collapse when it became clear that it could not explain the patterns found by paleontologists in the fossil record, which was non-linear with many complications. The hypothesis was generally abandoned when no mechanism could be found that would account for the process, and the theory of evolution by natural selection became the prevailing theory of evolution. The modern evolutionary synthesis, in which the genetic mechanisms of evolution were discovered, refuted the hypothesis for good. As more was understood about these mechanisms it became obvious that there was no possible naturalistic way in which the newly discovered mechanism of heredity could be far-sighted or have a memory of past trends.

The orthogenetic hypothesis, however, died hard. Even Darwin was at first not opposed to orthogenic thinking, as this quote from the 1911 Encyclopedia Britannica demonstrates:

Darwin and his generation were deeply imbued with the Butlerian tradition, and regarded the organic world as almost a miracle of adaptation, of the minute dovetailing of structure, function and environment. Darwin certainly was impressed with the view that natural selection and variation together formed a mechanism, the central product of which was adaptation. From the Butlerian side, too, came the most urgent opposition to Darwinism. How is it possible, it was said, that fortuitous variations can furnish the material for the precise and balanced adaptations that all nature reveals? Selection cannot create the materials on which it is supposed to operate; the beginnings of new organs, the initial stages of new functions cannot be supposed to have been useful. Moreover, many naturalists, especially those concerned with palaeontology, pointed to the existence of orthogenetic series, of long lines of ancestry, which displayed not a sporadic differentiation. in every direction, but apparently a steady and progressive march in one direction.[15]

Edward Drinker Cope put such a line of argument in the most cogent fashion; the course of evolution, both in the production of variations and their selection, seemed to him to imply the existence of an originative, conscious and directive force, for which he invented the term bathmism (Gr. βαθμ, a step or beginning). On the other hand, dislike of mystical interpretations of natural facts has driven many capable naturalists to another extreme and has led them to insist on the all-powerfulness of natural selection and on the complete indefiniteness of variation. The apparent opposition between the conflicting schools is more acute than the facts justify.... there is no connection between the appearance of the variation and the use to which it may be put... in one sense it is a mere coincidence if a particular variation turn out to be useful. But there are several directions in which the field of variation appears to be not only limited but defined in a certain direction. Obviously variations depend on the constitution of the varying organism; a modification, whether it be large or small, is a modification of an already definite and limited structure.... A continuous environment both from the point of view of production of variation and selection of variation would appear necessarily to result in a series with the appearance of orthogenesis. The past history of the organic world displays many successful series and these, as they have survived, must inevitably display orthogenesis to some extent; but it also displays many failures which indeed may be regarded as showing that the limitation of variation has been such that the organisms have lost the possibility of successful response to a new environment.[15]

A few hung on to the orthogenesis hypothesis as late as the 1950s by claiming that the processes of macroevolution, the long term trends in evolution, were distinct from the processes of microevolution (genetic variation and natural selection) which were by then well understood and it was known they could not behave in an orthogenetic manner. Teilhard de Chardin, a Jesuit paleontologist, in The Phenomenon of Man (a book influential among non-scientists that was published four years after his death in 1959) argued for evolution aiming for the "Omega Point", while putting man at the center of the universe and accounting for original sin (Dennett 1995, von Kitzing 1998). The term Chardin used for this was "directed additivity". This form of orthogenesis has now also been abandoned as more about evolutionary processes has been discovered (Wilkins 1997).

The refutation of orthogenesis had some ramifications in the field of philosophy, as it refuted the idea of teleology as first postulated by Aristotle and accepted by Immanuel Kant, who had greatly influenced many scientists. Before the scientific and philosophical revolution that began with Charles Darwin's ideas, the prevailing philosophy was that the world was teleological and purposeful, and that science was the study of God's creation. The refutation of these concepts have led to a shift in what science and scientists are perceived to be.

Modern co-opted usage

Though linear teleological evolution has been refuted, it is not true that evolution never proceeds in a linear way, reinforcing characteristics, in certain lineages at times, for example, during a period of slow, sustained environmental change, but such examples are entirely consistent with the modern neo-Darwinian theory of evolution. These examples have sometimes been referred to as orthoselection (e.g. by Jacobs et al. 1995; Ranganath & Hägele, 1981) but are not strictly orthogenetic, and simply appear as linear and constant changes because of environmental and molecular constraints on the direction of change.

See also

References

  1. ^ George Gaylord Simpson, Life of the Past: An Introduction to Paleontology, Yale University Press, New Haven, 1953, p. 125.
  2. ^ The evolutionary future of man: A biological view of progress
  3. ^ The phenomenon of Teilhard: prophet for a new age, David H. Lane, 1996, p. 61
  4. ^ Genesis: the evolution of biology, Jan Sapp, 2003, pp. 69-70
  5. ^ Evolution: the history of an idea, Peter J. Bowler, 1989, p. 268
  6. ^ Fight to Save the Redwoods: A History of the Environmental Reform, 1917-1978, Susan R. Schrepfer, 1983, pp. 81-82
  7. ^ The eclipse of Darwinism: anti-Darwinian evolution theories in the decades around 1900, Peter J. Bowler, The John Hopkins University Press, 1992
  8. ^ The evolution of Darwinism: selection, adaptation, and progress in evolutionary biology, Timothy Shanahan, 2004, p. 121
  9. ^ The structure of evolutionary theory, Stephen Jay Gould, 2002, pp. 355-364
  10. ^ Darwin's Dilemma: The Odyssey of Evolution, Stephen Jay Gould, an essay in Ever Since Darwin: Reflections in Natural History, W. W. Norton, 1977, ISBN 0-393-06425-5
  11. ^ http://www.jstor.org/stable/2456225
  12. ^ http://embryo.asu.edu/view/embryo:125550
  13. ^ The structure of evolutionary theory, Stephen Jay Gould, 2002, p. 283
  14. ^ Austin Hobart Clark, The New Evolution: Zoogenesis, 1930
  15. ^ a b The Encyclopaedia Britannica: A Dictionary of Arts, Sciences, Literature and General Information, Eleventh Edition, Copyright in all countries subscribing the Berne Convention by the Chancellor, Masters and Scholars of the University of Cambridge, Copyright in the United States of America by the Encyclopaedia Britannica Company, London, May 31, 1911.

Sources

  1. Bateson, William, 1909. Heredity and variation in modern lights, in Darwin and Modern Science (A.C. Seward ed.). Cambridge University Press. Chapter V. E-book.
  2. Dennett, Daniel, 1995. Darwin's Dangerous Idea. Simon & Schuster.
  3. Huxley, Julian, 1942. The Modern Evolutionary Synthesis, London: George Allen and Unwin.
  4. Jacobs, Susan C., Allan Larson & James M. Cheverud, 1995. Phylogenetic Relationships and Orthogenetic Evolution of Coat Color Among Tamarins (Genus Saguinus). Syst. Biol. 44(4):515—532, Abstract.
  5. Mayr, Ernst, 2002. What Evolution Is, London: Weidenfeld and Nicolson.
  6. Simpson, George G., 1957. Life Of The Past: Introduction to Paleontology. Yale University Press, p.119.
  7. Wilkins, John, 1997. What is macroevolution?. TalkOrigins Archive [1] (14:08 UTC, Oct 13 2004)
  8. Ranganath, H. A., & Hägel, K, 1981. Karyotypic orthoselection in Drosophila. Natur Wissenschaften. 68(10):527-528, [2].

 This article incorporates text from a publication now in the public domainChisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press. 


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Look at other dictionaries:

  • orthogenesis — orthogenesis. См. ортоэволюция. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Orthogeněsis — (griech., »geradlinige [bestimmt gerichtete] Entwickelung«), die allmählich verstärkte Ausprägung bestimmter Merkmale, die dadurch hervorgerufen wird, daß die aufeinander folgenden Generationen einer Tier oder Pflanzenart stets in gleicher… …   Meyers Großes Konversations-Lexikon

  • orthogenesis — [ôr΄thō jen′ə sis] n. [ModL: see ORTHO & GENESIS] 1. Biol. a now discredited theory that states that the progressive evolution of certain organisms in a restricted direction throughout successive generations is independent of outside influences… …   English World dictionary

  • orthogenesis — /awr theuh jen euh sis/, n. 1. Biol. a. Also called orthoselection. evolution of a species proceeding by continuous structural changes in a single lineage without presenting a branching pattern of descent. b. a theory that the evolution of a… …   Universalium

  • orthogenesis — noun Etymology: New Latin Date: 1895 variation of organisms in successive generations that in some especially former evolutionary theories takes place in some predestined direction resulting in progressive evolutionary trends independent of… …   New Collegiate Dictionary

  • orthogenesis — n. [Gr. orthos, straight; genesis, beginning] Evolution following a predetermined rectilinear pathway, independent of natural selection …   Dictionary of invertebrate zoology

  • orthogenesis — noun A series of similar in successive , producing evolutionary change …   Wiktionary

  • orthogenesis — The doctrine that evolution is governed by intrinsic factors and occurs in predictable directions. [ortho + G. genesis, origin] * * * or·tho·gen·e·sis .ȯr thə jen ə səs n, pl e·ses .sēz variation of organisms in successive generations that in… …   Medical dictionary

  • orthogenesis — directional evolution of organisms Causation and Formation …   Phrontistery dictionary

  • orthogenesis — n. theory that evolution of a species is predetermined and is unaltered by outside influences (Biology); theory that all cultures must pass through determined identical stages (Sociology) É”rθə dÊ’É™nɪsɪs / ɔːθ …   English contemporary dictionary


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