Fig 1.
Sampling locations and study site geography.
The numbered white circles show the 12 sample sites. The red squares show the locations of the five shipping terminals. The rivers and estuary are shown in blue. High-capacity highways are plotted as wide, light grey lines, while the greater highway network is in black. The background shading describes the average interpolated Breteau Index score: 0–2 (dark grey); 2–4 (grey); 4–6 (light grey). The underlying road network is derived from the Chinese "Highways" shapefile made available by MapCruzin.com and OpenStreetMap.org under the Open Database License [https://opendatacommons.org/licenses/odbl/1.0/].
Table 1.
Results of Mantel and partial Mantel tests.
Cells contain r scores and shaded cells indicate statistical significance at P < 0.001. Mantel tests are between landscape variables (including geographic distance) and Rousset’s a, and between landscape variables and geographic distance. Partial Mantel tests are between landscape variables and Rousset’s a, after accounting for geographic distance. The number of Type I error simulations (out of 100) showing significance is indicated for each partial Mantel test.
Fig 2.
Loiselle’s k scores for pairs of individuals and (inset) a histogram showing the frequencies of these scores.
Most related pairs were found within sample sites, but several pairs were found between two sites 3.657m apart. Pairs with k > 0.258 were resolved as definite full-siblings using conservative maximum-likelihood specific tests. The half-sibling pair with the lowest k showed clear separation from all pairs of lower relatedness. Few related pairs had k scores close to the full-sibling/half-sibling category boundary (inset).
Fig 3.
Relationship between pairwise Nei’s D estimates and geographic distance.
Red triangles show distances involving Site 4, which was highly differentiated from all others. Yellow diamonds denote distances between Sites 1,2,3,5–10 and Site 11, blue squares denote the same but for Site 12. Distances between Sites 11 and 12 are shown by the green square. White on grey crosses show distances for Sites 1,2,3,5–10.
Table 2.
The order of inclusion of variables is indicated for each model. Cells containing the effect sizes of variables retained in dbRDA2 that are shaded indicate significance at P < 0.01. The number of type I error simulations (out of 100) showing significance is indicated for each variable in dbRDA2.
Fig 4.
Locations of mtDNA and wAlbB haplotype variants.
Pie charts represent mtDNA haplotypes, with the following legend: white = the single common haplotype; yellow = rare haplotype A, 1 SNP; red = rare haplotype B, 3 SNPs; dark grey = rare haplotypes of variable divergence, each confined to one sample site. One SNP in wAlbB was found in three individuals from different sites, these are indicated with a blue ring.