The control of gene flow across a narrow hybrid zone: a selective role for chromosomal rearrangement?
Shaw, D.D.; Marchant, A.D.; Arnold, M.L.; Contreras, N.; Kohlmann, B.
Canadian Journal of Zoology 68(8): 1761-1769
ISSN/ISBN: 0008-4301 DOI: 10.1139/z90-257
Independent molecular, biochemical and cytological markers were used to assess the evolutionary status of a narrow hybrid zone between 2 genomically distinct taxa of Caledia captiva. Despite the extreme narrowness (<1 km) of the hybrid zone when assessed in terms of its chromosomal profile, other diagnostic nuclear and cytoplasmic markers were found at high frequencies in populations up to 400 km beyond the chromosomal limits of the zone. It is suggested that the hybrid zone is very old and capable of moving while still retaining its narrow chromosomal profile.