Speciation by Monobrachial Centric Fusions

Fixation of centric fusions in natural populations often encounters minimal meiotic problems due to the ability of trivalents to segregate normally; therefore, little sterility barrier is achieved between a founder population and the parental stock. However, a strong sterility barrier can develop be...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 1986-11, Vol.83 (21), p.8245-8248
Main Authors: Baker, Robert J., Bickham, John W.
Format: Article
Language:English
Subjects:
Acrocentric chromosomes
Biological and medical sciences
Biological evolution
Biological Sciences: Evolution
Chromosomes
Evolution
Evolutionary genetics
Fundamental and applied biological sciences. Psychology
Genetics of eukaryotes. Biological and molecular evolution
Heterozygotes
Hybridity
Population genetics
Reproductive isolation
Speciation
Taxa
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Summary:Fixation of centric fusions in natural populations often encounters minimal meiotic problems due to the ability of trivalents to segregate normally; therefore, little sterility barrier is achieved between a founder population and the parental stock. However, a strong sterility barrier can develop between different founder populations fixed for centric fusions that are monobrachially homologous in the resulting biarmed chromosomes (one arm is homologous but the other is nonhomologous). Hybridization through secondary contact then results in complex multivalents, which encounter problems in segregation and produce unbalanced gametes. Speciation mediated by centric fusions is a peripatric speciation model that does not postulate populational phenomena atypical of those characteristic of most mammals. The model appears applicable to a diversity of mammalian taxa such as bats of the Rhogeessa tumida-parvula complex, shrews of the Sorex araneus complex, and rodents of the Mus musculus and Rattus rattus complexes.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.83.21.8245