Open AccessDistribution of genetic diversity within and between Western Mediterranean island populations of the black rat Rattus rattus (L. 1758)
Author(s) -
Cheylan Gilles,
Granjon Laurent,
BrittonDavidian Janice
Publication year - 1998
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/j.1095-8312.1998.tb01525.x
Subject(s) - biology , genetic diversity , ecology , mediterranean climate , mainland , founder effect , genetic structure , phylogeography , colonization , population , zoology , genetic variation , phylogenetics , demography , allele , genetics , sociology , gene , haplotype
Genetic diversity was estimated by allozyme analysis at 26 loci in black rat populations (Rattus rattus) from 15 western Mediterranean islands (Hyéres, Corsica, Sardinia and related islets). Although overall variability levels were low (H = 0.025), the mean heterozygosity values for the islands were similar to those for three reference mainland populations. Within the islands, however, genetic diversity varied in relation to island size and geographic isolation. In particular, most small insular populations were significantly more variable than those on both large and isolated islands. The generic relationships between island populations were established by F ST analyses indicating possible geographic origins and patterns of colonization. The maintenance of unexpectedly high levels of variability in the small island populations is discussed in relation to changes in the demographic and social structure observed in these populations. These island populations of black rat illustrate how genetic diversity may be efficiently maintained in a series of interconnected spatially fragmented populations.