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Modern synthesis


Source: http://en.wikipedia.org/wiki/Modern_synthesis
Updated: 2017-08-31T18:37Z
Several major ideas about evolution came together in the population genetics of the early 20th century to form the modern synthesis, including genetic variation, natural selection, and particulate (Mendelian) inheritance.[1] This ended the eclipse of Darwinism and supplanted a variety of non-Darwinian theories of evolution.

The modern synthesis[a] was the early 20th-century synthesis reconciling Charles Darwin's theory of evolution and Gregor Mendel's ideas on heredity in a joint mathematical framework. Julian Huxley invented the term in his 1942 book, Evolution: The Modern Synthesis.

The 19th century ideas of natural selection by Darwin and Mendelian genetics were put together with population genetics, early in the twentieth century. The modern synthesis also addressed the relationship between the broad-scale changes of macroevolution seen by palaeontologists and the small-scale microevolution of local populations of living organisms. The synthesis was defined differently by its founders, with Ernst Mayr, Theodosius Dobzhansky and G. Ledyard Stebbins for example offering differing numbers of basic postulates in their definitions, though they all included natural selection, working on the heritable variation supplied by mutation. Other major figures in the synthesis included E. B. Ford, Bernhard Rensch, Ivan Schmalhausen, and George Gaylord Simpson.

Further syntheses came later, including evolutionary developmental biology's integration of embryology with genetics and evolution, starting in 1977, and Massimo Pigliucci's proposed extended evolutionary synthesis of 2007.

Developments leading up to the synthesis

Darwin's evolution by natural selection, 1859

Charles Darwin's On the Origin of Species (1859) was successful in convincing most biologists that evolution had occurred, but was less successful in convincing them that natural selection was its primary mechanism. In the 19th and early 20th centuries, variations of Lamarckism, orthogenesis ('progressive' evolution), and saltationism (evolution by jumps) were discussed as alternatives.[2] As part of the disagreement about whether natural selection alone was sufficient to explain speciation, George Romanes coined the term neo-Darwinism to refer to the version of evolution advocated by Alfred Russel Wallace and August Weismann, which relied on natural selection.[1] Weismann and Wallace rejected the Lamarckian idea of inheritance of acquired characteristics, something that Darwin had not ruled out.[3]

The eclipse of Darwinism, 1880s onwards

Darwin's pangenesis theory. Every part of the body emits tiny gemmules which migrate to the gonads and contribute to the next generation via the fertilised egg. Changes to the body during an organism's life would be inherited, as in Lamarckism.

From the 1880s onwards, there was a widespread belief among biologists that Darwinian evolution was in deep trouble, principally because experiments had failed to show that progressive evolution could gradually modify species by making many changes to small inherited variations. This eclipse of Darwinism (in Julian Huxley's phrase) grew out of the weaknesses in Darwin's account, written without knowledge of the mechanism of inheritance. Darwin himself believed in blending inheritance, which implied that any new variation, even if beneficial, would be weakened by 50% at each generation. This in turn meant that small variations would not survive long enough to be selected for. Blending would therefore directly oppose natural selection. In addition, Darwin and others considered Lamarckian inheritance of acquired characteristics entirely possible, and Darwin's 1868 theory of pangenesis, with contributions to the next generation (gemmules) flowing from all parts of the body, actually implied Lamarckism.[4][5][6]

August Weismann's germ plasm theory. The hereditary material, the germ plasm, is confined to the gonads and the gametes. Somatic cells (of the body) develop afresh in each generation from the germ plasm.

Weismann's germ plasm, 1892

Weismann's idea, set out in his 1892 book Das Keimplasma: eine Theorie der Vererbung (The Germ Plasm: a theory of inheritance),[7] was that the relationship between the hereditary material, which he called the germ plasm (German, Keimplasma), and the rest of the body (the soma) was a one-way relationship: the germ-plasm formed the body, but the body did not influence the germ-plasm, except indirectly in its participation in a population subject to natural selection. If correct, this made Darwin's pangenesis wrong and Lamarckian inheritance impossible. His experiment on mice, cutting off their tails and showing that their offspring had normal tails, demonstrated that inheritance was 'hard', not Lamarckian. He argued strongly and dogmatically[8] for Darwinism and against Lamarckism, polarising opinions among other scientists. This increased anti-Darwinian feeling, contributing to its eclipse.[9][10]

Genetics, mutationism and biometrics, 1900–1918

Gregor Mendel's work was re-discovered by Hugo de Vries and Carl Correns in 1900. News of this reached William Bateson in England, who reported on the paper during a presentation to the Royal Horticultural Society in May 1900.[11] In Mendelian inheritance, the contributions of each parent retain their integrity rather than blending with the contribution of the other parent. In the case of a cross between two true-breeding varieties such as Mendel's round and wrinkled peas, the first-generation offspring are all alike, in this case all round. Allowing these to cross, the original characteristics reappear (segregation): about 3/4 of their offspring are round, 1/4 wrinkled. There is a discontinuity between the appearance of the offspring; de Vries coined the term allele for a variant form of an inherited characteristic. This reinforced a major division of thought, already present in the 1890s, between gradualists who followed Darwin, and saltationists such as Bateson.[12]

The two schools were:

A traditional view is that the biometricians and the Mendelians rejected natural selection and argued for their separate theories for 20 years, the debate only resolved by the development of population genetics, giving a date of 1918 for the start of the supposed synthesis after a period of eclipse.[15][17]

A more recent view, advocated by the historians Arlin Stoltzfus and Kele Cable, is that Bateson, de Vries, Morgan and Reginald Punnett had by 1918 formed a synthesis of Mendelism and mutationism. The understanding achieved by these geneticists spanned the action of natural selection on alleles (alternative forms of a gene), the Hardy-Weinberg equilibrium, the evolution of continuously-varying traits (like height), and the probability that a new mutation will become fixed. In this view, the early geneticists accepted natural selection but rejected Darwin's non-Mendelian ideas about variation and heredity, and the synthesis began soon after 1900.[18] The traditional claim that Mendelians rejected the idea of continuous variation is false; as early as 1902, Bateson and Saunders wrote that "If there were even so few as, say, four or five pairs of possible allelomorphs, the various homo- and hetero-zygous combinations might, on seriation, give so near an approach to a continuous curve, that the purity of the elements would be unsuspected".[19]

Thomas Hunt Morgan began his career in genetics as a saltationist, and started out trying to demonstrate that mutations could produce new species in fruit flies. However, the experimental work at his lab with the common fruit fly, Drosophila melanogaster, which helped establish the link between Mendelian genetics and the chromosomal theory of inheritance, demonstrated that rather than creating new species in a single step, mutations increased the genetic variation in the population.[20]

Events in the synthesis

Fisher, Haldane and Wright's population genetics, 1918–1930

In 1918, R. A. Fisher wrote the paper "The Correlation between Relatives on the Supposition of Mendelian Inheritance,"[21] which showed mathematically how continuous variation could result from a number of discrete genetic loci. In this and subsequent papers culminating in his 1930 book The Genetical Theory of Natural Selection,[22] Fisher showed how Mendelian genetics was consistent with the idea of evolution driven by natural selection.[23]

During the 1920s, a series of papers by J. B. S. Haldane applied mathematical analysis to real-world examples of natural selection, such as the evolution of industrial melanism in peppered moths.[23] Haldane established that natural selection could work even faster than Fisher had assumed.[24] Fisher also analysed sexual selection in his book, but his work was largely ignored, and Darwin's case for such selection misunderstood, so it formed no substantial part of the modern synthesis.[25]

Sewall Wright focused on combinations of genes that interacted as complexes, and the effects of inbreeding on small relatively isolated populations, which could exhibit genetic drift. In a 1932 paper, he introduced the concept of an adaptive landscape in which phenomena such as cross breeding and genetic drift in small populations could push them away from adaptive peaks, which would in turn allow natural selection to push them towards new adaptive peaks.[23][26] Wright's model would appeal to field naturalists such as Theodosius Dobzhansky and Ernst Mayr who were becoming aware of the importance of geographical isolation in real world populations.[24] The work of Fisher, Haldane and Wright helped to found the discipline of theoretical population genetics.[27][28][29]

De Beer's embryology, 1930

In his 1930 book Embryos and Ancestors, the evolutionary embryologist Gavin de Beer anticipated evolutionary developmental biology by showing that evolution could occur by heterochrony, such as in the retention of juvenile features in the adult. This, he argued, could cause apparently sudden changes in the fossil record as embryos fossilise poorly.[30] The traditional view is that developmental biology played little part in the modern synthesis,[31] but Stephen Gould argues that de Beer made a significant contribution.[32]

Dobzhansky's population genetics, 1937

Theodosius Dobzhansky, an emigrant from the Soviet Union to the United States, who had been a postdoctoral worker in Morgan's fruit fly lab, was one of the first to apply genetics to natural populations. He worked mostly with Drosophila pseudoobscura. He says pointedly: "Russia has a variety of climates from the Arctic to sub-tropical... Exclusively laboratory workers who neither possess nor wish to have any knowledge of living beings in nature were and are in a minority."[33] Not surprisingly, there were other Russian geneticists with similar ideas, though for some time their work was known to only a few in the West. His 1937 work Genetics and the Origin of Species[34] was a key step in bridging the gap between population geneticists and field naturalists. It presented the conclusions reached by Fisher, Haldane, and especially Wright in their highly mathematical papers in a form that was easily accessible to others. It also emphasized that real world populations had far more genetic variability than the early population geneticists had assumed in their models, and that genetically distinct sub-populations were important. Dobzhansky argued that natural selection worked to maintain genetic diversity as well as driving change. Dobzhansky had been influenced by his exposure in the 1920s to the work of a Russian geneticist Sergei Chetverikov who had looked at the role of recessive genes in maintaining a reservoir of genetic variability in a population before his work was shut down by the rise of Lysenkoism in the Soviet Union.[23][24]

Ford's ecological genetics, 1940

E. B. Ford studied polymorphism in the scarlet tiger moth for many years.

E. B. Ford was an experimental naturalist who wanted to test natural selection in nature, virtually inventing the field of ecological genetics.[35] His work on natural selection in wild populations of butterflies and moths was the first to show that predictions made by R. A. Fisher were correct. In 1940, he was the first to describe and define genetic polymorphism, and to predict that human blood group polymorphisms might be maintained in the population by providing some protection against disease.[36] His 1949 book Mendelism and Evolution,[37] helped to persuade Dobzhansky to change the emphasis in the third edition of his famous text from drift to selection.[38]

Schmalhausen's stabilizing selection, 1941

Ivan Schmalhausen developed the theory of stabilizing selection, publishing a paper in Russian titled "Stabilizing selection and its place among factors of evolution" in 1941 and a monograph "Factors of Evolution: The Theory of Stabilizing Selection" in 1945. He developed it from J. M. Baldwin's 1902 concept that changes induced by the environment will ultimately be replaced by hereditary changes (including the Baldwin effect on behaviour), following that theory's implications to their Darwinian conclusion, and bringing him into conflict with Lysenkoism. Schmalhausen observed that stabilizing selection would remove most variations from the norm, most mutations being harmful.[39][40][41]

Mayr's allopatric speciation, 1942

Ernst Mayr's key contribution to the synthesis was Systematics and the Origin of Species, published in 1942.[42] Mayr emphasized the importance of allopatric speciation, where geographically isolated sub-populations diverge so far that reproductive isolation occurs. He was skeptical of the reality of sympatric speciation believing that geographical isolation was a prerequisite for building up intrinsic (reproductive) isolating mechanisms. Mayr also introduced the biological species concept that defined a species as a group of interbreeding or potentially interbreeding populations that were reproductively isolated from all other populations.[23][24][43] Before he left Germany for the United States in 1930, Mayr had been influenced by the work of the German biologist Bernhard Rensch. In the 1920s Rensch, who like Mayr did field work in Indonesia, analyzed the geographic distribution of polytypic species and complexes of closely related species paying particular attention to how variations between different populations correlated with local environmental factors such as differences in climate. In 1947, Rensch published Neuere Probleme der Abstammungslehre. Die transspezifische Evolution (Evolution Above the Species Level).[44] This looked at how the same evolutionary mechanisms involved in speciation would explain the origins of the differences between higher level taxa. His writings contributed to the rapid acceptance of the synthesis in Germany.[45][46]

Simpson's palaeontology, 1944

George Gaylord Simpson argued against the naive view that evolution such as of the horse took place in a "straight-line". He noted that any chosen line is one path in a complex branching tree, natural selection having no imposed direction.

George Gaylord Simpson was responsible for showing that the modern synthesis was compatible with paleontology in his book Tempo and Mode in Evolution published in 1944. Simpson's work was crucial because so many paleontologists had disagreed, in some cases vigorously, with the idea that natural selection was the main mechanism of evolution. It showed that the trends of linear progression (in for example the evolution of the horse) that earlier paleontologists had used as support for neo-Lamarckism and orthogenesis did not hold up under careful examination. Instead the fossil record was consistent with the irregular, branching, and non-directional pattern predicted by the modern synthesis.[23][24]

Stebbins's botany, 1950

The botanist G. Ledyard Stebbins extended the synthesis to encompass botany including the important effects on speciation of hybridization and polyploidy in plants in his 1950 book Variation and Evolution in Plants.[23][47]

Definitions by the founders

The modern synthesis was defined differently by its various founders, with differing numbers of basic postulates, as shown in the table.

Definitions of the modern synthesis by its founders, as they numbered them
Component Mayr 1959 Dobzhansky, 1974 Stebbins, 1966
Mutation (1) yields genetic raw materials[48] (1) a source of variability, but not of direction[49]
Recombination (2) a source of variability, but not of direction[49]
Chromosomal organisation (3) affects genetic linkage, arranges variation in gene pool[49]
Randomness (1) in all events that produce new genotypes, e.g. mutation, recombination, fertilisation[50]
Natural selection (2) is only direction-giving factor,[50][51] as seen in adaptations to physical and biotic environment[50] (2) constructs evolutionary changes from genetic raw materials[48] (4) guides changes to gene pool[49]
Reproductive isolation (3) makes divergence irreversible in sexual organisms[48] (5) limits direction in which selection can guide the population[49]

Claims made for the synthesis

The modern synthesis of the early 20th century is claimed to have bridged the gap between evolution, experimental genetics, ecology, and paleontology. However, different advocates of the synthesis such as Dobzhansky, Huxley, and Mayr made different claims for it.[52][53][54]

Dobzhansky, 1937

By 1937, Dobzhansky was able to argue in his Genetics and the Origin of Species that mutations were the main source of evolutionary changes and variability, along with chromosome rearrangements, effects of genes on their neighbours during development, and polyploidy. Next, genetic drift (he used the term in 1941), selection, migration, and geographical isolation could change gene frequencies. Thirdly, mechanisms like ecological or sexual isolation and hybrid sterility could fix the results of the earlier processes.[55]

Huxley, 1942

In 1942, Julian Huxley's serious but popularising[56][57] Evolution: The Modern Synthesis introduced a name for the synthesis and intentionally set out to promote a "synthetic point of view" on the evolutionary process. He imagined a wide synthesis of many sciences: genetics, developmental physiology, ecology, systematics, palaeontology, cytology, and mathematical analysis of biology, and assumed that evolution would proceed differently in different groups of organisms according to how their genetic material was organised and their strategies for reproduction, leading to progressive but varying evolutionary trends.[57]

However, the book was not what it seemed. In the view of the philosopher of science Michael Ruse, and in Huxley's own opinion, Huxley was "a generalist, a synthesizer of ideas, rather than a specialist".[56] Ruse observes that Huxley wrote as if he were just adding empirical evidence to the mathematical framework established by Fisher and the population geneticists, but that this was not so. Huxley avoided mathematics, for instance not even mentioning Fisher's fundamental theorem of natural selection. Instead, Huxley used a mass of examples to demonstrate that natural selection is powerful, and that it works on Mendelian genes. The book was successful in its goal of persuading readers of the reality of evolution, effectively illustrating island biogeography, speciation, competition and so on. Huxley further showed that the appearance of orthogenetic trends - predictable directions for evolution - in the fossil record were readily explained as allometric growth (since parts are interconnected). All the same, Huxley did not reject orthogenesis out of hand, but maintained a belief in progress all his life, with Homo sapiens as the end point, and he had since 1912 been influenced by the vitalist philosopher Henri Bergson, though in public he maintained an atheistic position on evolution.[56]

Mayr, 1942

Also in 1942, Mayr's Systematics and the Origin of Species asserted the importance of and set out to explain population variation in evolutionary processes including speciation. He analysed in particular the effects of polytypic species, geographic variation, and isolation by geographic and other means.[58]

After the synthesis

Evolutionary developmental biology, 1977

The modern synthesis largely ignored embryonic development to explain the form of organisms, since population genetics appeared to be an adequate explanation of how forms evolved.[59][60] In 1977, recombinant DNA technology enabled biologists to start to explore the genetic control of development. The growth of evolutionary developmental biology from 1978, when Edward B. Lewis discovered homeotic genes, showed that many so-called toolkit genes act to regulate development, influencing the expression of other genes. It also revealed that some of the regulatory genes are extremely ancient, so that animals as different as insects and mammals share control mechanisms; for example, the Pax6 gene is involved in forming the eyes of mice and of fruit flies. Such deep homology provided strong evidence for evolution and indicated the paths that evolution had taken.[61]

Pigliucci's extended evolutionary synthesis, 2007

In 2007, more than half a century after the modern synthesis, Massimo Pigliucci called for an extended evolutionary synthesis to incorporate aspects of biology that had not been included or did not exist in the mid-20th century.[62][63] It revisits the relative importance of different factors, challenges assumptions made in the modern synthesis, and adds new factors[63][64] such as multilevel selection, transgenerational epigenetic inheritance, niche construction, and evolvability.[65][66][67]

Historiography

Looking back at the conflicting accounts of the modern synthesis, the historian Betty Smocovitis notes in her 1996 book Unifying Biology: The Evolutionary Synthesis and Evolutionary Biology that both historians and philosophers of biology have attempted to grasp its scientific meaning, but have found it "a moving target";[68] the only thing they agreed on was that it was a historical event.[68] In her words "by the late 1980s the notoriety of the evolutionary synthesis was recognized . . . So notorious did 'the synthesis' become, that few serious historically minded analysts would touch the subject, let alone know where to begin to sort through the interpretive mess left behind by the numerous critics and commentators".[69]

See also

Notes

  1. ^ Also known variously as the new synthesis, the modern evolutionary synthesis, the evolutionary synthesis, and the neo-Darwinian synthesis.

References

  1. ^ a b Gould 2002, p. 216
  2. ^ Bowler 2003, pp. 236–256
  3. ^ Kutschera, Ulrich (December 2003). "A comparative analysis of the Darwin-Wallace papers and the development of the concept of natural selection". Theory in Biosciences. Jena; Berlin & Heidelberg: Urban & Fischer; Springer-Verlag. 122 (4): 343–359. ISSN 1431-7613. doi:10.1007/s12064-003-0063-6. 
  4. ^ Gayon, Jean (1998). Darwinism's Struggle for Survival: Heredity and the Hypothesis of Natural Selection. Cambridge University Press. pp. 2–3. ISBN 978-0-521-56250-8. 
  5. ^ Darwin, Charles (1868). The variation of animals and plants under domestication. John Murray. ISBN 1-4191-8660-4. 
  6. ^ Holterhoff, Kate (2014). "The History and Reception of Charles Darwin's Hypothesis of Pangenesis". Journal of the History of Biology. 47: 661–695. 
  7. ^ Weismann, August (1892). Das Keimplasma: eine Theorie der Vererbung. Jena: Fischer. 
  8. ^ Bowler 1989, p. 248.
  9. ^ Bowler 2003, pp. 253–256
  10. ^ Bowler 1989, pp. 247–253, 257.
  11. ^ Ambrose, Mike. "Mendel's Peas". Norwich, UK: Germplasm Resources Unit, John Innes Centre. Retrieved 2015-05-22. 
  12. ^ Bateson 1894: Mutations (as 'sports') and polymorphisms were well known long before the Mendelian recovery.
  13. ^ Larson 2004, pp. 157–166
  14. ^ Bowler 1989, pp. 275–276
  15. ^ a b Grafen & Ridley 2006, p. 69
  16. ^ Provine 2001, p. 69
  17. ^ Olby, Robert (September 1989). "The Dimensions of Scientific Controversy: The Biometric-Mendelian Debate". The British Journal for the History of Science. 22 (3): 299–320. JSTOR 4026898. 
  18. ^ Stoltzfus, Arlin; Cable, Kele (2014). "Mendelian-Mutationism: The Forgotten Evolutionary Synthesis" (PDF). Journal of the History of Biology. 47: 501–546. doi:10.1007/s10739-014-9383-2. 
  19. ^ Bateson, William; Saunders, E. R. (1902). "Experimental Studies in the Physiology of Heredity". Royal Society. Reports to the Evolution Committee. 
  20. ^ Bowler 2003, pp. 271–272
  21. ^ Fisher, Ronald A. (January 1919). "XV.—The Correlation between Relatives on the Supposition of Mendelian Inheritance". Transactions of the Royal Society of Edinburgh. London: Robert Grant & Son; Williams & Norgate. 52 (2): 399–433. ISSN 0080-4568. OCLC 4981124. doi:10.1017/S0080456800012163.  "Paper read by J. Arthur Thomson on July 8, 1918 to the Royal Society of Edinburgh."
  22. ^ Fisher 1999
  23. ^ a b c d e f g Larson 2004, pp. 221–243
  24. ^ a b c d e Bowler 2003, pp. 325–339
  25. ^ Hosken, David J.; House, Clarissa M. (25 January 2011). "Sexual Selection". Current Biology. 21 (2): R62–R65. doi:10.1016/j.cub.2010.11.053. 
  26. ^ Wright 1932, pp. 356–366
  27. ^ Rose, Michael R.; Oakley, Todd H. (November 24, 2007). "The new biology: beyond the Modern Synthesis" (PDF). Biology Direct. BioMed Central. 2 (30). ISSN 1745-6150. PMC 2222615Freely accessible. PMID 18036242. doi:10.1186/1745-6150-2-30. 
  28. ^ Huxley, J. 1942. Evolution: The Modern Synthesis. Allen & Unwin, London.
  29. ^ Ridley, M. 1996. Evolution, 2nd ed. Blackwell Science, Cambridge, Mass, pp.
  30. ^ Ingo Brigandt (2006). "Homology and heterochrony: the evolutionary embryologist Gavin Rylands de Beer (1899-1972)" (PDF). Journal of Experimental Zoology. 306B (4): 317–328. PMID 16506229. doi:10.1002/jez.b.21100. 
  31. ^ Smocovitis 1996, p. 192
  32. ^ Gould 1977, pp. 221–222
  33. ^ Mayr & Provine 1998, p. 231
  34. ^ Dobzhansky 1937
  35. ^ Ford 1964
  36. ^ Ford 1964Ford 1975
  37. ^ Ford, E. B. (1949). Mendelism and Evolution. Methuen. 
  38. ^ Dobzhansky 1951
  39. ^ Levit, Georgy S.; Hossfeld, Uwe; Olsson, Lennart (2006). "From the 'Modern Synthesis' to Cybernetics: Ivan Ivanovich Schmalhausen (1884–1963) and his Research Program for a Synthesis of Evolutionary and Developmental Biology". Journal of Experimental Zoology. Wiley-Liss. 306B (2006): 89–106. PMID 16419076. 
  40. ^ Adams, M. B. (June 1988). "A Missing Link in the Evolutionary Synthesis. I. I. Schmalhausen. Factors of Evolution: The Theory of Stabilizing Selection". Isis. 79 (297): 281–284. 
  41. ^ Glass, Bentley (December 1951). "Reviews and Brief Notices Factors of Evolution. The Theory of Stabilizing Selection. I. I. Schmalhausen , Isadore Dordick , Theodosius Dobzhansky". Quarterly Review of Biology. 26 (4): 384–385. 
  42. ^ Mayr 1999
  43. ^ Mayr & Provine 1998, pp. 33–34
  44. ^ Rensch 1947; Rensch 1959
  45. ^ Smith, Charles H. "Rensch, Bernhard (Carl Emmanuel) (Germany 1900-1990)". Some Biogeographers, Evolutionists and Ecologists: Chrono-Biographical Sketches. Bowling Green, KY: Western Kentucky University. Retrieved 2015-05-22. 
  46. ^ Mayr & Provine 1998, pp. 298–299, 416
  47. ^ Smocovitis, V. B. (2001). "G. Ledyard Stebbins and the evolutionary synthesis". Annual Review of Genetics. 35: 803–814. PMID 11700300. doi:10.1146/annurev.genet.35.102401.091525. 
  48. ^ a b c Dobzhansky, T.: In: Ayala, F., Dobzhansky, T. (eds.) Chance and Creativity in Evolution, pp. 307–338. University of California Press, Berkeley and Los Angeles (1974)
  49. ^ a b c d e Stebbins, G.L.: Processes of Organic Evolution, p. 12. Prentice Hall, 1966
  50. ^ a b c Mayr, E.: Where Are We? Cold Spring Harbor Symposium of Quantitative Biology 24, 1–14, 1959
  51. ^ Mayr, E.: In: Mayr, E., Provine, W. (eds.) Some Thoughts on the History of the Evolutionary Synthesis, pp. 1–48. Harvard University Press, 1980
  52. ^ Huxley 2010
  53. ^ Mayr & Provine 1998
  54. ^ Mayr 1982, p. 567 et seq.
  55. ^ Eldredge, Niles (1985). Unfinished Synthesis: Biological Hierarchies and Modern Evolutionary Thought. Oxford University Press. p. 17. ISBN 978-0-19-536513-9. 
  56. ^ a b c Ruse 1996, pp. 328–338
  57. ^ a b Lamm, Ehud. "Review of: Julian Huxley, Evolution: The Modern Synthesis – The Definitive Edition, with a new forward by Massimo Pigliucci and Gerd B. Müller. MIT Press" (PDF). Retrieved 21 August 2017. 
  58. ^ Hey, Jody; Fitch, Walter M.; Ayala, Francisco J. (2005). "Systematics and the origin of species: An introduction". PNAS. 102 (supplement 1): 6515–6519. doi:10.1073/pnas.0501939102. 
  59. ^ Gilbert, S. F.; Opitz, J. M.; Raff, R. A. (1996). "Resynthesizing evolutionary and developmental biology". Developmental Biology. 173: 357–372. 
  60. ^ Adams, M. (1991). Warren, L. Warren; Koprowski, H., ed. Through the looking glass: The evolution of Soviet Darwinism. New Perspectives in Evolution. Liss/Wiley. pp. 37–63. 
  61. ^ Gilbert, S. F. (2000). A New Evolutionary Synthesis. Developmental Biology. Sinauer Associates. 
  62. ^ Wade, Michael J. (2011). "The Neo-Modern Synthesis: The Confluence of New Data and Explanatory Concepts". BioScience. 61 (5): 407–408. doi:10.1525/bio.2011.61.5.10. 
  63. ^ a b John Odling-Smee et al. "The extended evolutionary synthesis: its structure, assumptions and predictions". Proceedings of the Royal Society B: Biological Sciences, August 2015.
  64. ^ Wade, Michael J. (2011). "The Neo-Modern Synthesis: The Confluence of New Data and Explanatory Concepts". BioScience. 61: 407–408. doi:10.1525/bio.2011.61.5.10. 
  65. ^ Danchin, É.; Charmantier, A.; Champagne, F. A.; Mesoudi, A.; Pujol, B.; Blanchet, S. (2011). "Beyond DNA: integrating inclusive inheritance into an extended theory of evolution". Nature Reviews Genetics. 12: 475–486. PMID 21681209. doi:10.1038/nrg3028. 
  66. ^ Pigliucci, Massimo; Finkelman, Leonard (2014). "The Extended (Evolutionary) Synthesis Debate: Where Science Meets Philosophy". BioScience. 64: 511–516. doi:10.1093/biosci/biu062. 
  67. ^ Laubichler, Manfred D.; Renn, Jürgen (2015). "Extended evolution: A Conceptual Framework for Integrating Regulatory Networks and Niche Construction". Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 324: 565–577. doi:10.1002/jez.b.22631. 
  68. ^ a b Smocovitis 1996, p. 187
  69. ^ Smocovitis 1996, p. 43

Bibliography

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