Firstly, in haplodiploid systems bidirectional CI possesses a limited ability to maintain Wolbachia diversity and, by extrapolation, a limited ability to maintain genetic divergence of locally adapted genes.
During mutation, the genetic material of chromosomes get modified to maintain genetic diversity.
In conclusion, when both Wolbachia strains were maintained, enhancement of genetic divergence by bidirectional CI was weaker in haplodiploids than in other genetic systems.
Accordingly, the biology of the species (e.g. dispersal capacity), availability of suitable habitat and ocean current regimes, which determine the contemporary level of gene flow, would significantly contribute to promote, maintain or homogenize the genetic divergence created by glacial periods.
We find that morphological (bill size and plumage coloration) and life history (reproductive effort) differences observed between wild populations were maintained in laboratory raised individuals suggesting genetic divergence of fitness related traits.
In this study we analyze 22 consecutive populations of F. ceranoides along NW Iberia to investigate the processes generating and maintaining the observed high levels of regional genetic divergence.
This diversity is maintained by a delicate balance between disruptive selection pushing toward further genetic divergence and gene flow between the divergent forms, pushing toward a phenotypic and genetic homogenization (Seehausen 2000).
Balancing selection thus maintains a high level of polymorphism within populations but reduces genetic divergence between populations.
Since the importance of hybridization on the wild is increasingly recognized [ 64, 65], this process may be a significant factor maintaining and generating morphological diversity even among groups separated by overall little genetic divergence.
Our niche-based models suggest postglacial genetic divergence between these rivers may have partly been maintained by lack of predicted suitable habitat between these rivers.
