No New Species Have Been Observed
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[edit] Definition
The claim that no new species have been observed is a common creationist argument, though of late it has been diminishing in popularity.
[edit] Creationists in retreat
According to the Institute for Creationist Research:
- Not only could Darwin not cite a single example of a new species originating, but neither has anyone else, in all the subsequent century of evolutionary study. [1]
According to Answers In Genesis, however:
- New species have been observed to form. In fact, rapid speciation is an important part of the creation model. [2]
You may wonder at what point the evolution of new species stopped being part of the "missing evidence" and started being "an important part of the creation model". We suspect that it was at the precise moment at which creationists realized that speciation had been observed.
The headlong retreat continues:
- Genesis does not seem to have anything to say against microevolution and, perhaps, even some macroevolution, at least to the development of new genera. [3]
To put that in perspective for the lay reader, humans and orangutans are merely diferent genera of the same family, Hominidae.
[edit] Speciation observed
We list some of the more interesting examples of speciation to be found in the literature. More will be found in the links below.
In 1905, Hugo de Vries published his observations of several new species of primrose, including the giant evening primrose (Oenothera gigas), the dwarf evening primrose (O. nanella) and the red-veined evening primrose (O. rubrinervis) growing among the Lamarck's evening primrose (Oenothera lamarckiana). Lamarck's evening primrose itself was first described in Europe in the early nineteenth century, when it was brought from America. The new species did not produce fertile crosses with the parent species. (de Vries, 1905 [4])
Galeopsis tetrahit was believed to be the result of a polyploid cross of G. pubescens and G. speciosa --- that is, is was produced by a cross between them which cannot cross-breed with either of the parent species. In the 1930s, Muntzing reproduced the polyploid cross and replicated the species. Other recent species produced in the lab or in the wild by polyploid mutations include Tragopodon mirus and T. miscellus, Spartina anglica, Senecio cambrensis, Cardamine insueta and C. schulzii. [5]
One of the most often cited examples of speciation is Rhagoletis pomonella. in 1864, five years after the publication of the Origin of Species, the American biologist (and early supporter of Dawin) Benjamin Walsh hypothesized that agricultural pests, provided with an alternative food source, could and would divide into two populations which would differentiate into species symaptrically, that is, without any geographical barrier preventing the two populations from interbreeding (Walsh, 1864). Two years later, it was reported that the maggots of an unknown fly were infesting apples in the Hudson River Valley. While the new breed is genetically capaple of crossing with the other, it does not do so: the two species are biologically separated by different mate recognition systems. (Bush, 1992 [6])
In 1999, a new species of mosquito was discovered to have evolved to live in the London Underground and parasitize the rats. We should note that although the new species has sometimes been referred to as Culex molestus, this is taxonomically inaccurate, and the authors of the original paper, Byrne and Nichols, were careful to refer to the "so-called molestus form" (Byrne and Nichols, 1999 [7])
The new species of planktonic copepod Cyclops dimorphus was observed in the Salton Sea only three decades after the Salton Sea was formed: it seems to have evolved from a riparian species. (Johnson, 1953)
[edit] Note on the Woods Hole worms
In 1992, Weinberg et al reported evidence that a population of laboratory specimens of Nereis acuminata had become reproductively isolated from the wild type[8]. However further tests showed[9] that the genetic divergence between the supposed "wild type" and the laboratory strain was such as one might expect to evolve over six million years or so. It follows that the orginal research, which supposedly showed that the laboratory populations had diverged from the wild type, in reality merely showed that there were already two very similar-looking species in the genus Nereis.
We point this out because there are plenty of people who have heard about Weinberg's 1992 paper suggesting that speciation had taken place but have missed out on his 1996 paper saying that it didn't.
[edit] References
- Abbott R and Lowe, A. (2004) Origins, establishment and evolution of new polyploid species: Senecio cambrensis and S. eboracensis in the British Isles, Biological Journal of the Linnean Society 82:4, 467-474 [10]
- Boraas M., Seale B. and Boxhorn J. Phagotrophy by a flagellate selects for colonial prey: A possible origin of multicellularity, Evolutionary Ecology 1998, 12, 153±164 [11]
- Bush, G. L. Host race formation and sympatric speciation in Rhagoletis fruit flies. (Diptera: Tephritidae), Psyche vol 99 no. 4, 1992 [12]
- Byrne K., Nichols RA. Culex pipiens in London Underground tunnels: differentiation between surface and subterranean populations, Heredity. 1999 Jan;82 ( Pt 1):7-15. [13]
- de Vries, H. Species and Varieties, Their Origin By Mutation, 1905 [14]
- Digby, L. The cytology of Primula kewensis and of other related Primula hybrids. Ann. Bot. 26:357-388, 1912 [15]
- Filchak KE, Roethele JB, Feder JL. Natural selection and sympatric divergence in the apple maggot Rhagoletis pomonella. Nature. 2000 Oct 12;407(6805):739-42.[16]
- Franzke A. and Mummenhof K. Recent hybrid speciation in Cardamine (Brassicaceae) - conversion of nuclear ribosomal ITS sequences in statu nascendi, Theoretical and Applied Genetics, vol. 98, No. 5, 1999 [17]
- 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 [18]
- Huskins C. L. The origin of Spartina Townsendii, Genetica vol 12 no 6, 1930 [19]
- Johnson, M.W. 1953 The copepod Cyclops dimorphus Kiefer from the Salton Sea, American Midland Naturalist 49(1):188-192 [20]
- Pires et al. Molecular cytogenetic analysis of recently evolved Tragopogon (Asteraceae) allopolyploids reveal a karyotype that is additive of the diploid progenitors. American Journal of Botany. 2004;91:1022-1035. [21]
- Soltis P, Plunkett G, Novak S, Soltis D, Genetic Variation in Tragopogon Species: Additional Origins of the Allotetraploids T. mirus and T. miscellus (Compositae), American Journal of Botany, Vol. 82, No. 10 (Oct., 1995) , pp. 1329-1341 [22]
- Walsh, B. On phytophagic varieties and phytophagic species. Proc. Entomol. Soc. Phila. 3: 403-430. 1864
