Posted by:
Joe Forks
at Wed May 12 20:36:47 2010 [ Email Message ] [ Show All Posts by Joe Forks ]
Here's one
Speciation by hybridization in Heliconius butterflies
Jesús Mavárez1,4, Camilo A. Salazar2,4, Eldredge Bermingham1, Christian Salcedo2, Chris D. Jiggins3 and Mauricio Linares2
1. Smithsonian Tropical Research Institute, Apartado postal 0843-03092, Panamá, República de Panamá
2. Instituto de Genética, Universidad de los Andes, Carrera 1E No 18ª–10, PO Box 4976, Santafé de Bogotá D.C., Colombia
3. Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK
4. *These authors contributed equally to this work
Correspondence to: Jesús Mavárez1,4Mauricio Linares2 Correspondence and requests for materials should be addressed to M.L. (Email: mlinares@uniandes.edu.co) or J.M. (Email: mavarezj@si.edu). The sequences have been deposited in GenBank under accession numbers DQ445384–DQ445414 (Distal-less) and DQ445416–DQ445457 (Invected).
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Speciation is generally regarded to result from the splitting of a single lineage. An alternative is hybrid speciation, considered to be extremely rare, in which two distinct lineages contribute genes to a daughter species. Here we show that a hybrid trait in an animal species can directly cause reproductive isolation. The butterfly species Heliconius heurippa is known to have an intermediate morphology and a hybrid genome1, and we have recreated its intermediate wing colour and pattern through laboratory crosses between H. melpomene, H. cydno and their F1 hybrids. We then used mate preference experiments to show that the phenotype of H. heurippa reproductively isolates it from both parental species. There is strong assortative mating between all three species, and in H. heurippa the wing pattern and colour elements derived from H. melpomene and H. cydno are both critical for mate recognition by males.
here's two
Speciation via introgressive hybridization in East African cichlids?
Salzburger W, Baric S, Sturmbauer C.
Department of Zoology and Limnology, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria.
Abstract
Speciation caused by introgressive hybridization occurs frequently in plants but its importance remains controversial in animal evolution. Here we report a case of introgressive hybridization between two ancient and genetically distinct species of Lake Tanganyika cichlids that led to the formation of a new species. Neolamprologus marunguensis contains mtDNA haplotypes from both parental species varying on average by 12.4% in the first section of the control region and by 5.2% in a segment of the cytochrome b gene. All individuals have almost identical DNA sequences in the flanking regions of the single-copy nuclear DNA locus TmoM27, and show a mosaic of alleles derived from both parental lineages in six microsatellite loci. Hence, our finding displays another mode of speciation in cichlid fishes. The increase of genetic and phenotypic diversity due to hybridization may contribute to the uniquely rapid pace of speciation in cichlids.
OH LOOK, A UNIVERSITY THAT STUDIES HYBRID SPECIATION HAHAHA
http://www.zin.ru/labs/herplab/research4.html
Hybridogenic complexes of European green frogs, the diploid-tetraploid complex in green toads of Central Asia, and other interesting cases of uncommon speciation have been studied by Leo Borkin and his coauthors. Geographic (allopatric) speciation has also been studied. Levels of genetic heterozygosity and divergence (in biochemical loci) were estimated in continental and insular populations and in subspecies and closely related species of some groups of amphibians and reptiles.
Now Jeff, just because you DON'T KNOW IT, doesn't mean it isn't true! ----- Herp Conservation Unlimited
Conservation through captive propagation
Mexicana Group Directory
Photography by Joseph E. Forks
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