Radiación adaptativa: Diferenzas entre revisións
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== Identificación == |
== Identificación == |
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Poden usarse catro características para identificar unha radiación adaptativa, que son:<ref name="Schluter2000" /> |
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# Un antepasado común das especies compoñentes: especificamente un antepasado ''recente''. Nótese que isto non é o mesmo que unha [[monofilia]], na cal están incluídos ''todos'' os descendentes dun antepasado común. |
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# A common ancestry of component species: specifically a ''recent'' ancestry. Note that this is not the same as a [[monophyly]] in which ''all'' descendants of a common ancestor are included. |
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# Unha correlación fenotipo-ambiente: unha asociación ''significativa'' entre ambientes e os trazos morfolóxicos e fisiolóxicos usados para explotar eses ambientes. |
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# A phenotype-environment correlation: a ''significant'' association between environments and the morphological and physiological traits used to exploit those environments. |
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# Utilidade do trazo: as vantaxes de [[fitness (bioloxía)|fitness]] dos valores do trazo nos seus correspondentes ambientes. |
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# Trait utility: the performance or fitness advantages of trait values in their corresponding environments. |
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# Especiación rápida: presenza dunha ou máis ''explosións'' na emerxencia de novas especies no momento en que a diverxencia ecolóxica e fenotípica está comezando. |
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# Rapid speciation: presence of one or more ''bursts'' in the emergence of new species around the time that ecological and phenotypic divergence is underway. |
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== Causas == |
== Causas == |
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=== Innovación === |
=== Innovación === |
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The evolution of a novel feature may permit a clade to diversify by making new areas of morphospace accessible. A classic example is the evolution of a fourth cusp in the mammalian tooth. This trait permits a vast increase in the range of foodstuffs which can be fed on. Evolution of this character has thus increased the number of [[ecological niche]]s available to mammals. The trait arose a number of times in different groups during the [[Cenozoic]], and in each instance was immediately followed by an adaptive radiation.<ref name=Jernvall1996>{{Cite journal | first1 = J. | last1 = Jernvall | first2 = J. P. | last2 = Hunter | first3 = M. | last3 = Fortelius |
The evolution of a novel feature may permit a clade to diversify by making new areas of morphospace accessible. A classic example is the evolution of a fourth cusp in the mammalian tooth. This trait permits a vast increase in the range of foodstuffs which can be fed on. Evolution of this character has thus increased the number of [[ecological niche]]s available to mammals. The trait arose a number of times in different groups during the [[Cenozoic]], and in each instance was immediately followed by an adaptive radiation.<ref name=Jernvall1996>{{Cite journal | first1 = J. | last1 = Jernvall | first2 = J. P. | last2 = Hunter | first3 = M. | last3 = Fortelius |
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| title = Molar Tooth Diversity, Disparity, and Ecology in Cenozoic Ungulate Radiations |
| title = Molar Tooth Diversity, Disparity, and Ecology in Cenozoic Ungulate Radiations |
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[[Anolis]] lizards have been radiating widely in many different environments, including Central and South America, as well as the West Indies and experience great diversity of species just as the finches, cichlid fish, and silverswords. Studies have been done to determine whether radiations occur similarly for these lizards on the mainland as they do on the [[Caribbean islands]] or if differences can be observed in how they speciated. It has been observed that in fact, the radiations are very different, and ecological and morphological characteristics that these lizards developed as part of their speciation on the islands and on the mainland are unique.<ref>Irschick, Duncan J., et al. "A comparison of evolutionary radiations in mainland and Caribbean Anolis lizards." Ecology 78.7 (1997): 2191-2203.</ref> They have clearly evolved differently to the environments they inhabit. The environmental pressures on the Anolis lizards are not the same on the mainland as they are on the islands. There are significantly more [[predation|predators]] preying on the Anolis lizards on the mainland. This is but one environmental difference. Other factors play a role in what sort of adaptive radiation will develop. Among the Caribbean islands, a larger perch diameter correlates with longer forelimbs, larger body mass, longer tails, and longer hind limbs. However, on the mainland, a larger perch diameter correlates with shorter tails. This shows that these lizards adapted differently to their environment depending on whether they were located on the mainland or the islands. These differing characteristics reconfirm that most of the adaptive radiation between the mainland and the islands occurred independently. On the islands specifically, species have adapted to certain "microhabitats" in which they require different morphological traits to survive. Irschick (1997) divides these microhabitats into six groups: "trunk–ground, trunk–crown, grass–bush, crown–giant, twig, and trunk." Different groups of lizards would acquire traits for one of these particular areas that made them more specialized for survival in this microhabitat and not so much in others. Adaptive radiation allows species to acquire the traits they need to survive in these microhabitats and reduce competition to allow the survival of a greater number of organisms as seen in many of the examples before. |
[[Anolis]] lizards have been radiating widely in many different environments, including Central and South America, as well as the West Indies and experience great diversity of species just as the finches, cichlid fish, and silverswords. Studies have been done to determine whether radiations occur similarly for these lizards on the mainland as they do on the [[Caribbean islands]] or if differences can be observed in how they speciated. It has been observed that in fact, the radiations are very different, and ecological and morphological characteristics that these lizards developed as part of their speciation on the islands and on the mainland are unique.<ref>Irschick, Duncan J., et al. "A comparison of evolutionary radiations in mainland and Caribbean Anolis lizards." Ecology 78.7 (1997): 2191-2203.</ref> They have clearly evolved differently to the environments they inhabit. The environmental pressures on the Anolis lizards are not the same on the mainland as they are on the islands. There are significantly more [[predation|predators]] preying on the Anolis lizards on the mainland. This is but one environmental difference. Other factors play a role in what sort of adaptive radiation will develop. Among the Caribbean islands, a larger perch diameter correlates with longer forelimbs, larger body mass, longer tails, and longer hind limbs. However, on the mainland, a larger perch diameter correlates with shorter tails. This shows that these lizards adapted differently to their environment depending on whether they were located on the mainland or the islands. These differing characteristics reconfirm that most of the adaptive radiation between the mainland and the islands occurred independently. On the islands specifically, species have adapted to certain "microhabitats" in which they require different morphological traits to survive. Irschick (1997) divides these microhabitats into six groups: "trunk–ground, trunk–crown, grass–bush, crown–giant, twig, and trunk." Different groups of lizards would acquire traits for one of these particular areas that made them more specialized for survival in this microhabitat and not so much in others. Adaptive radiation allows species to acquire the traits they need to survive in these microhabitats and reduce competition to allow the survival of a greater number of organisms as seen in many of the examples before. |
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== Notas == |
== Notas == |
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Revisión como estaba o 10 de xullo de 2016 ás 22:51
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En bioloxía evolutiva, unha radiación adaptativa é un proceso no cal os organismos diversifícanse rapidamente a partir dunha especie ancestralnunha multitude de novas formas, especialmente cando o cambio no ambiente fai que queden dispoñibles novos recursos, creando novos retos, ou abrindo novos nichos.[1][2] Empezando cun só antepasado común, este proceso dá lugar a unha especiación e a adaptación fenotípica nun conxunto d e especies que mostran trazos morfolóxicos e fisiolóxicos diferentes cos cales poden explotar un abano de ambientes diverxentes.[2]
A radiación adaptativa, un xemplo característrico de cladoxénese, pode ser ilustrada graficamente como un "arbusto", ou clado, de especies que coexisten (na árbore da vida). [3] Os lagartos anolinos do Caribe son un exemplo particularmente interesante dunha radiación adaptativa.[4] As illas Hawai son un arquipélago moi illado e nel se encontran moitos exemplos de radiación adaptativa. Un exemplo excepcional de radiación adaptativa é o das especies de aves do xénero Cyanerpes hawaianas. Por medio da selección natural, estes paxaros adaptáronse rapidamente e converxeron segundo os dferentes ambientes das illas hawaianas nos que vivían.[5]
Realizáronse moitas investigacións sobre a radiación adaptativa debido aos seus drásticos efectos na diversidade da poboación. Porén, cómpre facer máis investigación, especialmente para comprender completamente os moitos factores que afectan á radiación adaptativa. Os enfoques empíricos e teóricos son ambos útiles, aínda que cada un ten as súas desvantaxes.[6]
Identificación
Poden usarse catro características para identificar unha radiación adaptativa, que son:[2]
- Un antepasado común das especies compoñentes: especificamente un antepasado recente. Nótese que isto non é o mesmo que unha monofilia, na cal están incluídos todos os descendentes dun antepasado común.
- Unha correlación fenotipo-ambiente: unha asociación significativa entre ambientes e os trazos morfolóxicos e fisiolóxicos usados para explotar eses ambientes.
- Utilidade do trazo: as vantaxes de fitness dos valores do trazo nos seus correspondentes ambientes.
- Especiación rápida: presenza dunha ou máis explosións na emerxencia de novas especies no momento en que a diverxencia ecolóxica e fenotípica está comezando.
Causas
Innovación
Notas
- ↑ Larsen, Clark S. (2011). Our Origins: Discovering Physical Anthropology (2 ed.). Norton. p. A11.
- ↑ 2,0 2,1 2,2 Schluter, Dolph (2000). The Ecology of Adaptive Radiation. Oxford University Press. pp. 10–11. ISBN 0-19-850523-X.
- ↑ Lewin, Roger (2005). Human evolution : an illustrated introduction (5th ed.). p. 21. ISBN 1-4051-0378-7.
- ↑ Parallel Adaptive Radiations - Caribbean Anoline Lizards. Tood Jackman. Villanova University. Retrieved 10 September 2013.
- ↑ Reding, DM; Foster, JT; James, HF; Pratt, D; Fleischer, RC (2009). "Convergent evolution of 'creepers' in the Hawaiian honeycreeper radiation". Biology Letters 5: 221–224. doi:10.1098/rsbl.2008.0589.
- ↑ Gavrilets, S.; Losos, J. B. (2009). "Adaptive radiation: contrasting theory with data". Science 323 (5915): 732–737. doi:10.1126/science.1157966.
Véxase tamén
Outros artigos
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Commons ten máis contidos multimedia sobre: Radiación adaptativa |
- Explosión cámbrica—a radiación adaptativa de máis sona
- Radiación evolutiva—un temo máis xeral para describir calquera radiación
Bibliografía
- Wilson, E. et al. Life on Earth, by Wilson, E.; Eisner, T.; Briggs, W.; Dickerson, R.; Metzenberg, R.; O'brien,R.; Susman, M.; Boggs, W.; (Sinauer Associates, Inc., Publishers, Stamford, Connecticut), c 1974. Chapters: The Multiplication of Species; Biogeography, pp 824–877. 40 Graphs, w species pictures, also Tables, Photos, etc. Includes Galápagos Islands, Hawaii, and Australia subcontinent, (plus St. Helena Island, etc.).
- Leakey, Richard. The Origin of Humankind—on adaptive radiation in biology and human evolution, pp. 28–32, 1994, Orion Publishing.
- Grant, P.R. 1999. The ecology and evolution of Darwin's Finches. Princeton University Press, Princeton, NJ.
- Mayr, Ernst. 2001. What evolution is. Basic Books, New York, NY.
- Kemp, A.C. (1978). "A review of the hornbills: biology and radiation". The Living Bird 17: 105–136.
- Gavrilets, S.; Vose, A. (2005). "Dynamic patterns of adaptive radiation". Proc. Natl. Acad. Sci. USA 102: 18040–18045. doi:10.1073/pnas.0506330102.
- Gavrilets, S. and A. Vose. 2009. Dynamic patterns of adaptive radiation: evolution of mating preferences. In Butlin, RK, J Bridle, and D *Schluter (eds) Speciation and Patterns of Diversity, Cambridge University Press, page. 102–126.
- Baldwin, Bruce G.; Sanderson, Michael J. (1998). "Age and rate of diversification of the Hawaiian silversword alliance (Compositae)". Proceedings of the National Academy of Sciences 95 (16): 9402–9406. doi:10.1073/pnas.95.16.9402.
- Gavrilets, S.; Losos, J. B. (2009). "Adaptive radiation: contrasting theory with data". Science 323 (5915): 732–737. doi:10.1126/science.1157966.
- Irschick, Duncan J.; et al. (1997). "A comparison of evolutionary radiations in mainland and Caribbean Anolis lizards". Ecology 78 (7): 2191–2203. doi:10.2307/2265955.
- Losos, Jonathan B (2010). "Adaptive Radiation, Ecological Opportunity, and Evolutionary Determinism". The American Naturalist 175 (6): 623–39. doi:10.1086/652433.
- Petren, K.; Grant, P. R.; Grant, B. R.; Keller, L. F. (2005). "Comparative landscape genetics and the adaptive radiation of Darwin's finches: the role of peripheral isolation". Molecular Ecology 14 (10): 2943–2957. doi:10.1111/j.1365-294x.2005.02632.x.
- Pinto, Gabriel, Luke Mahler, Luke J. Harmon, and Jonathan B. Losos. "Testing the Island Effect in Adaptive Radiation: Rates and Patterns of Morphological Diversification in Caribbean and Mainland Anolis Lizards." NCBI (2008): n. pag. Web. 28 Oct. 2014.
- Rainey, P. B.; Travisano, M. (1998). "Adaptive radiation in a heterogeneous environment". Nature 394 (6688): 69–72. doi:10.1038/27900.
- Schluter, D (1995). "Adaptive radiation in sticklebacks: trade-offs in feeding performance and growth". Ecology: 82–90.
- Schluter, Dolph. The ecology of adaptive radiation. Oxford University Press, 2000.
- Seehausen, O (2004). "Hybridization and adaptive radiation". Trends in Ecology & Evolution 19 (4): 198–207. doi:10.1016/j.tree.2004.01.003.