Authors: Chris Stassen (stassen@netcom.uucp), jwm@sun4.uucp (James W. Meritt), Anneliese L

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====================================================================== Authors: Chris Stassen (stassen@netcom.uucp), jwm@sun4.uucp (James W. Meritt), Anneliese Lilje (anne@cco.caltech.edu), L. Drew Davis (drewd@terminus.gatech.edu) Title: A List of Observed Speciation Events ====================================================================== By Chris Stassen: Here is a short list of referenced speciation events. I picked four relatively well-known examples, from about a dozen that I had documented in materials that I have around my home. These are all common knowledge, and by no means do they encompass all or most of the available examples. Example one: A strain of _drosophilia paulistorum_ developed hybrid sterility after being isolated in the lab for only a couple of years. (Test for speciation: offspring are not fertile, like horse vs. donkey.) Dobzhansky, Th., and O. Pavlovsky, 1971. "An experimentally created incipient species of Drosophilia", _Nature_ 23:289-292. Example two: Evidence that a species of fireweed formed by doubling of the chromosome count, from the original stock. (Note that polyploids are generally considered to be a separate "race" of the same species as the original stock, but they do meet the criteria which you suggested.) (Test for speciation: cannot produce offspring with the original stock.) Mosquin, T., 1967. "Evidence for autopolyploidy in _Epilobium angustifolium_ (Onaagraceae)", _Evolution_ 21:713-719 Example three: Rapid speciation of the Faeroe Island house mouse, which occurred in less than 250 years after man brought the creature to the island. (Test for speciation in this case is based on morphology. It is unlikely that forced breeding experiments have been performed with the parent stock.) Stanley, S., 1979. _Macroevolution: Pattern and Process_, San Francisco, W.H. Freeman and Company. p. 41 Example four: Formation of five new species of cichlid fishes which formed since they were isolated less than 4000 years ago from the parent stock, Lake Nagubago. (Test for speciation in this case is by morphology and lack of natural interbreeding. These fish have complex mating rituals and different coloration. While it might be possible that different species are inter-fertile, they cannot be convinced to mate.) Mayr, E., 1970. _Populations, Species, and Evolution_, Massachusetts, Harvard University Press. p. 348 ---------------------------------------------------------------------- By Jim Meritt: cosc143u@elroy.uh.edu (91F9774) writes: >I have a friend who says since we have never seen a species actually >split into two different species during recorded history that he has >trouble believing in the theory of evolution. > >1) Is this bogus and have humans seen animals bred into different > species? (The various highly bred english dogs come to mind but I > suppose this would be easier to find in vegetation (corn, wheat > strains?), Donkey/Mules? ) This is bogus. We've seen it happen naturally WITHOUT our tampering with the process. >From the FAQ: "Three species of wildflowers called goatsbeards were introduced to the United States from Europe shortly after the turn of the century. Within a few decades their populaltions expanded and began to encounter one another in the American West. Whenever mixed populations occurred, the specied interbred (hybridizing) producing sterile hybrid offspring. Suddenly, in the late forties two new species of goatsbeard appeared near Pullman, Washington. Although the new species were similliar in appearance to the hybrids, they pproduced fertile offspring. The evollutionary process had created a separate species that could reproduce but not mate with the goatsbeard plants from which it had evolved." The article is on page 22 of the February, 1989 issue of _Scientific_American_. It's called "A Breed Apart." It tells about studies conducted on a fruit fly, Rhagoletis pomonella, that is a parasite of the hawthorn tree and its fruit, which is commonly called the thorn apple. About 150 years ago, some of these flies began infesting apple trees, as well. The flies feed an breed on either apples or thorn apples, but not both. There's enough evidence to convince the scientific investigators that they're witnessing speciation in action. Note that some of the investigators set out to prove that speciation was not happening; the evidence convinced them otherwise. ---------------------------------------------------------------------- By Anneliese Lilje: Just a smattering of a HUGE database of articles: (1991 only) 1) Bullini, L and Nascetti, G, 1991, Speciation by Hybridization in phasmids and other insects, Canadian Journal of Zoology, Volume 68(8), pages 1747-1760. 2) Ramadevon, S and Deaken, M.A.B., 1991, The Gibbons speciation mechanism, Journal of Theoretical Biology, Volume 145(4) pages 447-456. 3) Sharman, G.B., Close, R.L, Maynes, G.M., 1991, Chromosome evolution, phylogony, and speciation of rock wallabies, Australian Journal of Zoology, Volume 37(2-4), pages 351-363. 4) Werth, C. R., and Windham, M.D., 1991, A model for divergent, allopatric, speciation of polyploid pteridophytes resulting from silencing of duplicate- gene expression, AM-Natural, Volume 137(4):515-526. 5) Spooner, D.M., Sytsma, K.J., Smith, J., A Molecular reexamination of diploid hybrid speciation of Solanum-raphanifolum, Evolution, Volume 45, Number 3, pages 757-764. 6) Arnold, M.L., Buckner, C.M., Robinson, J.J., 1991, Pollen-mediated introgression and hybrid speciation in Louisana Irises, P-NAS-US, Volume 88, Number 4, pages 1398-1402. 7) Nevo, E., 1991, Evolutionary Theory and process of active speciation and adaptive radiation in subterranean mole rats, spalax-ehrenbergi superspecies, in Isreal, Evolutionary Biology, Volume 25, pages 1-125. .... on and on to about #50 if you like... There are about 100 each for every year before 1991 to 1987 in my database.... ---------------------------------------------------------------------- By L. Drew Davis: A LIST OF SPECIATION REFERENCES: Weiberg, James R.. Starczak, Victoria R.. Jorg, Daniele. Evidence for rapid speciation following a founder event in the laboratory. Evolution. V46. P1214(7) August, 1992. Kluger, Jeffrey. Go fish. (rapid fish speciation in African lakes). Discover. V13. P18(1) March, 1992. Hauffe, Heidi C.. Searle, Jeremy B.. A disappearing speciation event? (response to J.A. Coyne, Nature, vol. 355, p. 511, 1992) Nature. V357. P26(1) May 7, 1992 Abstract AB: Analysis of contact between two chromosomal races of house mice in northern Italy show that natural selection will produce alleles that bar interracial matings if the resulting offspring are unfit hybrids. This is an important exception to the general rule that intermixing races will not tend to become separate species because the constant sharing of genes minimizes the genetic diversity requisite for speciation. Barrowclough, George F.. Speciation and Geographic Variation in Black-tailed Gnatcatchers. (book reviews) The Condor. V94. P555(2) May, 1992 Rabe, Eric W.. Haufler, Christopher H.. Incipient polyploid speciation in the maidenhair fern (Adiantum pedatum; Adiantaceae)? The American Journal of Botany. V79. P701(7) June, 1992. Nores, Manuel. Bird speciation in subtropical South America in relation to forest expansion and retraction. The Auk. V109. P346(12) April, 1992 Abstract AB: The climatic and geographic history of the Pleistocene and Holocene periods modified the distribution of the bird population in the South American forests. Forest birds are found dispersed in the Yungas and Paranese areas with only minimal infiltration of the Chaco woodland, indicating an atmospheric change during the interglacial periods. In the Chaco lowlands, the interactions between non-forest birds reveal the existence of presence of a forest belt along the Bermejo and Pilcomayo rivers. Kondrashov, Alexey S.. Jablonka, Eva. Lamb, Marion J.. Species and speciation. (response to J.A. Coyne, Nature, vol. 355, p. 511, 1992) Nature. V356. P752(1) April 30, 1992 Abstract AB: J.A. Coyne wrongly asserted that neodarwinism includes allopatric evolution but not sympatric evolution. Allopatric evolution occurs among geographically isolated populations, whereas sympatric evolution occurs within one species' entire population. Both are neodarwinian since each results from natural selection of genetic variation. Also, Coyne failed to recognize that the molecular models used to illustrate how genetic changes bring on speciation are most useful when researchers acknowledge that both inherited epigenetic and genetic changes affect speciation. Spooner, David M.. Sytsma, Kenneth J.. Smith, James F.. A molecular reexamination of diploid hybrid speciation of Solanum raphanifolium. Evolution. V45. P757(8) May, 1991 Orr, H. Allen. Is single-gene speciation possible?. Evolution. V45. P764(6) May, 1991 Miller, Julie Ann. Pathogens and speciation. (Research Update). BioScience. V40. P714(1) Nov, 1990. Barton, N.H. Hewitt, G.M. Adaptation, speciation and hybrid zones; many species are divided into a mosaic of genetically distinct populations, separated by narrow zones of hybridization. Studies of hybrid zones allow us to quantify the genetic differences responsible for speciation, to measure the diffusion of genes between diverging taxa, and to understand the spread of alternative adaptations. (includes related information) Nature. V341. P497(7) Oct 12, 1989. Wright, Karen. A breed apart; finicky flies lend credence to a theory of speciation. Scientific American. V260. P22(2) Feb, 1989. Coyne, Jerry A. Orr, H. Allen. Patterns of speciation in Drosophila. Evolution. V43. P362(20) March, 1989. Feder, Jeffrey L. Bush, Guy L. A field test of differential host-plant usage between two sibling species of Rhagoletis pomonella fruit flies (Diptera: Tephritidae) and its consequences for sympatric models of speciation. Evolution. V43. P1813(7) Dec, 1989. Soltis, Douglas E. Soltis, Pamela S. Allopolyploid speciation in Tragopogon: insights from chloroplast DNA. The American Journal of Botany. V76. P1119(6) August, 1989. Coyne, J.A. Barton, N.H. What do we know about speciation?. Nature. V331. P485(2) Feb 11, 1988. Barton, N.H. Jones, J.S. Mallet, J. No barriers to speciation. (morphological evolution). Nature. V336. P13(2) Nov 3, 1988. Kaneshiro, Kenneth Y. Speciation in the Hawaiian drosophila: sexual selection appears to play an important role. BioScience. V38. P258(6) April, 1988. FROM TALK.ORIGINS: 1) Speciation occured in a strain of Drosophila paulistorum sometime between 1958 and 1963 in Theodosius Dobzhansky's lab. He wrote this up in: Dobzhansky, T. 1973. Species of Drosophila: New Excitement in an Old Field. Science 177:664-669 2) A naturally occurring speciation of a plant species, Stephanomeria malheurensis, was observed in Burns County, Oregon. The citing is: Gottlieb, L. D. 1973. Genetic differentiation, sympatric speciation, and the origin of a diploid species of Stephanomeria. American Journal of Botany 60(6):545-553 3) In the 1940's a fertile species was produced through chromosome doubling (allopolyploidy) in a hybrid of two primrose species. The new species was Primula kewensis. The story is recounted in: Stebbins, G. L. 1950. Variation and Evolution in Plants. Columbia University Press. New York 4) Finally, two workers produced reproductiove isolation between two strains of fruit flies in a lab setting within 25 generations. I don't have the paper handy, so I can't give the species. The partial citing of the paper is: Rice and Salt 1988. American Naturalist 131:911- Dohbzhansky got a subpopulation of _D. paulistorum to speciate in his lab. The reference is: Dobxhansky and Pavlovsky, 1957 An experimentallly created incipient species of Drosophila, Nature 23: 289- 292 See also: Weinberg, et. al, 1992 Evidence for rapid speciation following a founder event in the laboratory, Evolution 46: 1214 This isn't a full paper (just a note) -- it describes what is probably speciation of a type of polychaete worm. ~~~~~~~~~~ There are two distinct strains of *Rhagoletis pomonella*, the apple maggot fly. One infests the apple, the other the hawthorn. They have different breeding times--as the fruits flower at different times--and so they do not interbreed in the real world. I do not know if they could interbreed in the laboratory. Since the fly is not found in Europe, and the apple is an import from Europe, the only presumption is that the apple strain is a speciation off the original hawthorn strain. ~~~~~~~~~~~ I do not currently have references to cite for the speciation of fish, however I have a couple for the case of rats. Genus _Rattus_ currently consists of 137 species [1,2] and is known to have originally developed in Indonesia and Malaysia during and prior to the Middle Ages [3]. ([1] is the only source I have consulted.) [1] T. Yosida. Cytogenetics of the Black Rat. University Park Press, Baltimore, 1980. [2] D. Morris. The Mammals. Hodder and Stoughton, London, 1965. [3] G. H. H. Tate. "Some Muridae of the Indo-Australian region," Bull. Amer. Museum Nat. Hist. 72: 501-728, 1963.

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