Although there is equivocal evidence for natal philopatry (returning to one's birthplace to breed) in this species, proximity to established breeding grounds likely contributes to the structuring of these different subpopulations.
For example, differences in nest predator abundance and diversity between breeding sites likely selects for different nest sizes.
Therefore, complete panmixia seems unlikely and fine scale subdivision of the breeding stock likely occurs in the spawning areas.
Suitable breeding habitats likely existed in east Asia, probably at least partly within the present breeding ranges of these lineages, e.g. Japan.
In addition to hatchery versus wild origin, individual traits such as body size and the timing of breeding are likely to affect the RS of salmon colonists.
A 5k SNP panel appeared to give significantly lower accuracy of breeding value, likely due to insufficient LD, with such large distances between SNPs.
Our findings support both studies because changes in the proportion of younger- and older-maturing males, sex ratio and breeding density likely caused fluctuations in selection.
For example, timing of breeding is likely to influence the probability of nest destruction by later spawning females, which in turn may vary with breeding density (e.g. Hendry et al. 1999; Dickerson et al. 2005).
Given the high natal dispersal of the species [ 14], males caught at the same site during breeding are likely to be unrelated and thus represent independent samples of the subspecies originating from a larger area.
Thus, the A. dumetorum collected in the area of likely A. orinus breeding range are most likely migrant individuals passing through or non-breeding individuals.
