Some More Observed Speciation Events
Copyright © 1992-1997 by Chris Stassen
L. Drew Davis
ere 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.
Two strains of Drosophila paulistorum developed hybrid sterility of male offspring between 1958 and 1963. Artificial selection induced strong intra-strain mating preferences.
(Test for speciation: sterile offspring and lack of interbreeding affinity.)
Dobzhansky, Th., and O. Pavlovsky, 1971. "An experimentally created incipient species of Drosophila", Nature 23:289-292.
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
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
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
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. 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? Donkeys and 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 populations 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 similar in appearance to the hybrids, they produced fertile offspring. The evolutionary 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 and 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.
... on and on to about #50 if you like...
There are about 100 each for every year before 1991 to 1987 in my database.
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.
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.
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.
A talk.origins participant writes:
1) Speciation occured in a strain of Drosophila paulistorum sometime between 1958 and 1963 in Theodosius Dobzhansky's lab. He wrote this up in:Another talk.origins participant writes: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 reproductive 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-
Dobzhansky got a subpopulation of D. paulistorum to speciate in his lab. The reference is:
Dobzhansky and Pavlovsky, 1957 An experimentally created incipient species of Drosophila, Nature 23: 289- 292
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.
Yet another talk.origins participant writes:
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 . ( is the only source I have consulted.)
 T. Yosida. Cytogenetics of the Black Rat. University Park Press, Baltimore, 1980.
 D. Morris. The Mammals. Hodder and Stoughton, London, 1965.
 G. H. H. Tate. "Some Muridae of the Indo-Australian region," Bull. Amer. Museum Nat. Hist. 72: 501-728, 1963.
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