Open AccessEffects of the East Australian Current on the genetic structure of a direct developing muricid snail ( Bedeva hanleyi , Angas): variability within and among local populations
Author(s) -
HOSKIN M. G.
Publication year - 2000
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.1095-8312.2000.tb01201.x
Subject(s) - biology , gene flow , locus (genetics) , intertidal zone , population , genetic structure , genetic variability , snail , latitude , genetic variation , ecology , population genetics , zoology , demography , genetics , geography , gene , genotype , geodesy , sociology
This paper examines the model that the East Australian Current (EAC) is an important determinant of genetic structure for the direct developing intertidal snail Bedeva hanleyi. Above latitude 33 o S on the east coast of Australia the EAC typically flows parallel to the shore in a southerly direction, whilst below 33 o S the direction of flow is predominantly offshore. Based on this flow‐pattern it was predicted that B. hanleyi should exhibit greater genetic subdivision in the region south of 33 o S, due to smaller amounts of inter‐population gene‐flow via rafting. To test this hypothesis, collections of 45 individuals were made from each of 10–32 local populations/˜ 400 km region. Data for six polymorphic and apparently unlinked allozyme loci were consistent with the hypothesized effects of the EAC. Local populations from the northern region exhibited significantly more alleles per locus (mean = 2.2, cf. 1.8 for southern populations) and greater Hardy‐Weinberg‐expected heterozygosities (mean = 0.299, cf. 0.185 for southern populations) (one‐tailed t ‐test; P <0.05 in each case). Moreover, the weighted jackknife ±mean SE) standardized genetic variance (θ) among southern populations (0.156 ± 0.025) was more than 50% higher than that among northern populations (0.103 ± 0.018).