Macroevolution

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Macroevolution in the modern sense is evolution that is guided by selection among interspecific variation, as opposed to selection among intraspecific variation in microevolution.[1][2][3] This modern definition differs from the original concept, which referred macroevolution to the evolution of taxa above the species level (genera, families, orders etc.).[4]

Origin and changing meaning of the term[edit]

Philiptschenko[4] distinguished between microevolution and macroevolution because he rejected natural selection in the sense of Darwin[5] as an explanation for larger evolutionary transitions that give rise to taxa above the species level in the Linnean taxonomy. Accordingly, he restricted Darwinian "microevolution" to evolutionary changes within the boundary of given species that may lead to different races or subspecies at the most. By contrast, he referred "macroevolution" to major evolutionary changes that correspond to taxonomic differences above the species level, which in his opinion would require evolutionary processes different from natural selection. An explanatory model for macroevolution in this sense was the "hopeful monster" concept of geneticist Richard Goldschmidt, who suggested saltational evolutionary changes either due to mutations that affect the rates of developmental processes[6] or due to alterations in the chromosomal pattern.[7] Particularly the latter idea was widely rejected by the modern synthesis and is disproved today, but the hopeful monster concept based on evo-devo explanations found a moderate revival in recent times.[8][9] As an alternative to saltational evolution, Dobzhansky [10] suggested that the difference between macroevolution and microevolution reflects essentially a difference in time-scales, and that macroevolutionary changes were simply the sum of microevolutionary changes over geologic time. This view became broadly accepted, and accordingly, the term macroevolution has been used widely as a neutral label for the study of evolutionary changes that take place over a very large time-scale.[11] However, the tenet that large-scale evolutionary patterns were ultimately reducible to microevolution has been challenged by the concept of species selection,[1] which suggests that selection among species is a major evolutionary factor that is independent from and complementary to selection among organisms. Accordingly, the level of selection (or, more generally, of sorting) has become the conceptual basis of a third definition, which defines macroevolution as evolution through selection among interspecific variation.[3]

Macroevolutionary processes[edit]

Speciation[edit]

According to the modern definition, the evolutionary transition from the ancestral to the daughter species is microevolutionary, because it results from selection (or, more generally, sorting) among varying organisms. However, speciation has also a macroevolutionary aspect, because it produces the interspecific variation species selection operates on.[3] Another macroevolutionary aspect of speciation is the rate at which it successfully occurs, analogous to reproduction success in microevolution.[1]

Species selection[edit]

"Species selection operates on variation provided by the largely random process of speciation and favors species that speciate at high rates or survive for long periods and therefore tend to leave many daughter species."[1] Species selection comprises (a) effect-macroevolution, where organism-level traits (aggregate traits) affect speciation and extinction rates (Stanley’s original concept), and (b) strict-sense species selection, where species-level traits (e.g. geographical range) affect speciation and extinction rates.[12] It has been argued that effect macroevolution is reducible to microevolution because both operate through selection on organismic traits,[13] but Grantham[14] demonstrated that effect macroevolution can oppose selection at the organismic level and is therefore not reducible microevolution. Cases in which selection on the same trait has opposing effects at the organismic and the species level have been made in the context of sexual selection,[15][16][17] which increases individual fitness but may also increase the extinction risk of the species.

Punctuated equilibrium[edit]

Punctuated equilibrium postulates that evolutionary change is concentrated during a geologically short speciation phase, which is followed by evolutionary stasis that persists until the species goes extinct.[18][19] The prevalence of evolutionary stasis through most of the existence time of species is a major argument for the relevance of species selection in shaping the evolutionary history of clades. However, punctuated equilibrium is neither a macroevolutionary model of speciation, nor is it a prerequisite for species selection.[12]

Examples[edit]

Evolutionary faunas[edit]

A macroevolutionary benchmark study is Sepkoski's[20][21] work on marine animal diversity through the Phanerozoic. His iconic diagram of the numbers of marine families from the Cambrian to the Recent illustrates the successive expansion and dwindling of three "evolutionary faunas" that were characterized by differences in origination rates and carrying capacities.

Mass extinctions[edit]

The macroevolutionary relevance of environmental changes is most obvious in the case of global mass extinction events. Such events are usually due to massive disturbances of the non-biotic environment that occur too fast for a microevolutionary response through adaptive change. Mass extinctions therefore act nearly excursively through selection among species, i.e., macroevolutionary. In their differential impact on species, mass extinctions introduce a strong non-adaptive aspect to evolution.[22] A classic example in this context is the suggestion that the decline of brachiopods that is apparently mirrored by the rise of bivalves was actually caused by differential survival of these clades during the end-Permian mass extinction.[23]

Stanley's rule[edit]

Macroevolution is driven by differences between species in origination and extinction rates. Remarkably, these two factors are generally positively correlated: taxa that have typically high diversification rates have also high extinction rates. This observation has been described first by Steven Stanley, who attributed it to a variety of ecological factors.[24] Yet, a positive correlation of origination and extinction rates is also a prediction of the Red Queen hypothesis, which postulates that evolutionary progress (increase in fitness) of any given species causes a decrease in fitness of other species, ultimately driving to extinction those species that do not adapt rapidly enough.[25] High rates of origination must therefore correlate with high rates of extinction.[3] Stanley's rule, which applies to almost all taxa and geologic ages, is therefore a strong indication for a dominant role of biotic interactions in macroevolution.

Research topics[edit]

Subjects studied within macroevolution include:[26]

See also[edit]

References[edit]

  1. ^ a b c d Stanley, S. M. (1 February 1975). "A theory of evolution above the species level". Proceedings of the National Academy of Sciences. 72 (2): 646–650. Bibcode:1975PNAS...72..646S. doi:10.1073/pnas.72.2.646. ISSN 0027-8424. PMC 432371. PMID 1054846.
  2. ^ Gould, Stephen Jay. (2002). The structure of evolutionary theory. Cambridge, Mass.: Belknap Press of Harvard University Press. ISBN 0-674-00613-5. OCLC 47869352.
  3. ^ a b c d Hautmann, Michael (2020). "What is macroevolution?". Palaeontology. 63 (1): 1–11. doi:10.1111/pala.12465. ISSN 0031-0239.
  4. ^ a b Philiptschenko, J. (1927). Variabilität und Variation. Berlin: Borntraeger.
  5. ^ Darwin, C. (1859). On the origin of species by means of natural selection. London: John Murray.
  6. ^ Goldschmidt, R. (1933). "Some aspects of evolution". Science. 78 (2033): 539–547. Bibcode:1933Sci....78..539G. doi:10.1126/science.78.2033.539. PMID 17811930.
  7. ^ Goldschmidt, R. (1940). The material basis of evolution. Yale University Press.
  8. ^ Theißen, Günter (March 2009). "Saltational evolution: hopeful monsters are here to stay". Theory in Biosciences. 128 (1): 43–51. doi:10.1007/s12064-009-0058-z. ISSN 1431-7613. PMID 19224263. S2CID 4983539.
  9. ^ Rieppel, Olivier (13 March 2017). Turtles as hopeful monsters : origins and evolution. Bloomington, Indiana. ISBN 978-0-253-02507-4. OCLC 962141060.
  10. ^ Dobzhanski, T. (1937). Genetics and the origin of species. Columbia University Press.
  11. ^ Dawkins, Richard, 1941- (1982). The extended phenotype : the gene as the unit of selection. Oxford [Oxfordshire]: Freeman. ISBN 0-7167-1358-6. OCLC 7652745.CS1 maint: multiple names: authors list (link)
  12. ^ a b Jablonski, David (December 2008). "Species Selection: Theory and Data". Annual Review of Ecology, Evolution, and Systematics. 39 (1): 501–524. doi:10.1146/annurev.ecolsys.39.110707.173510. ISSN 1543-592X.
  13. ^ Greenwood, P. H. (1979). "Macroevolution - myth or reality ?". Biological Journal of the Linnean Society. 12 (4): 293–304. doi:10.1111/j.1095-8312.1979.tb00061.x.
  14. ^ Grantham, T A (November 1995). "Hierarchical Approaches to Macroevolution: Recent Work on Species Selection and the "Effect Hypothesis"". Annual Review of Ecology and Systematics. 26 (1): 301–321. doi:10.1146/annurev.es.26.110195.001505. ISSN 0066-4162.
  15. ^ McLain, Denson K.; Moulton, Michael P.; Redfearn, Todd P. (October 1995). "Sexual Selection and the Risk of Extinction of Introduced Birds on Oceanic Islands". Oikos. 74 (1): 27. doi:10.2307/3545671. ISSN 0030-1299. JSTOR 3545671.
  16. ^ Moen, R. A. "Antler growth and extinction of Irish elk". Evolutionary Ecology Research. 1: 235–249.
  17. ^ Martins, Maria João Fernandes; Puckett, T. Markham; Lockwood, Rowan; Swaddle, John P.; Hunt, Gene (April 2018). "High male sexual investment as a driver of extinction in fossil ostracods". Nature. 556 (7701): 366–369. Bibcode:2018Natur.556..366M. doi:10.1038/s41586-018-0020-7. ISSN 0028-0836. PMID 29643505. S2CID 4925632.
  18. ^ Eldredge, N.; Gould, S. J. (1972). Punctuated equilibria: an alternative to phyletic gradualism. pp. 82–115.
  19. ^ Gould, Stephen Jay; Eldredge, Niles (1977). "Punctuated equilibria: the tempo and mode of evolution reconsidered". Paleobiology. 3 (2): 115–151. doi:10.1017/s0094837300005224. ISSN 0094-8373.
  20. ^ Sepkoski, J. John (1981). "A factor analytic description of the Phanerozoic marine fossil record". Paleobiology. 7 (1): 36–53. doi:10.1017/s0094837300003778. ISSN 0094-8373.
  21. ^ Sepkoski, J. John (1984). "A kinetic model of Phanerozoic taxonomic diversity. III. Post-Paleozoic families and mass extinctions". Paleobiology. 10 (2): 246–267. doi:10.1017/s0094837300008186. ISSN 0094-8373.
  22. ^ Gould, Stephen Jay (1985). "The paradox of the first tier: an agenda for paleobiology". Paleobiology. 11 (1): 2–12. doi:10.1017/s0094837300011350. ISSN 0094-8373.
  23. ^ Gould, Stephen Jay; Calloway, C. Bradford (1980). "Clams and brachiopods—ships that pass in the night". Paleobiology. 6 (4): 383–396. doi:10.1017/s0094837300003572. ISSN 0094-8373.
  24. ^ Stanley, Steven M. (1979). Macroevolution, pattern and process. San Francisco: W.H. Freeman. ISBN 0-7167-1092-7. OCLC 5101557.
  25. ^ Van Valen, L. (1973). "A new evolutionary law". Evolutionary Theory. 1: 1–30.
  26. ^ Grinin, L., Markov, A. V., Korotayev, A. Aromorphoses in Biological and Social Evolution: Some General Rules for Biological and Social Forms of Macroevolution / Social evolution & History, vol.8, num. 2, 2009 [1]

Further reading[edit]

External links[edit]