--- res: bibo_abstract: - The common shrew (Sorex araneus) is subdivided into several karyotypic races in Britain. Two of these races meet near Oxford to form the "Oxford-Hermitage" hybrid zone. We present a model which describes this system as a "tension zone," i.e., a set of clines maintained by a balance between dispersal and selection against chromosomal heterozygotes. The Oxford and Hermitage races differ by Robertsonian fusions with monobrachial homology (kq, no versus ko), and so F1 hybrids between them would have low fertility. However, the acrocentric karyotype is found at high frequency within the hybrid zone, so that complex Robertsonian heterozygotes (kq no/q ko n) are replaced by more fertile combinations, such as (kq no/k q n o). This suggests that the hybrid zone has been modified so as to increase hybrid fitness. Mathematical analysis and simulation show that, if selection against complex heterozygotes is sufficiently strong relative to selection against simple heterozygotes, acrocentrics increase, and displace the clines for kq and no from the cline for ko. Superimposed on this separation is a tendency for the hybrid zone to move m favor of the Oxford (kq no) race. We compare the model with estimates of linkage disequilibrium and cline shape made from field data.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Todd foaf_name: Hatfield, Todd foaf_surname: Hatfield - foaf_Person: foaf_givenName: Nicholas H foaf_name: Barton, Nicholas H foaf_surname: Barton foaf_workInfoHomepage: http://www.librecat.org/personId=4880FE40-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-8548-5240 - foaf_Person: foaf_givenName: Jeremy foaf_name: Searle, Jeremy foaf_surname: Searle bibo_doi: 10.1111/j.1558-5646.1992.tb00624.x bibo_issue: '4' bibo_volume: 46 dct_date: 1992^xs_gYear dct_isPartOf: - http://id.crossref.org/issn/0014-3820 - http://id.crossref.org/issn/1558-5646 dct_language: eng dct_publisher: Wiley-Blackwell@ dct_title: A model of a hybrid zone between two chromosomal races of the common shrew (Sorex araneus)@ fabio_hasPubmedId: '28564402' ...