N Bierne

..Global hitchhiking is a neglected phenomenon that might prove to be important in species with large population sizes such as many marine invertebrates...

..25). We validated the outlier status of this locus, and analysed DNA sequence polymorphism in order to identify the nature of the selection responsible for the unusual differentiation...

..However, Dirichlet-based estimators were less biased than the product-rule estimator, which ignores coancestry...

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..We argue that selective constraints for optimal codon usage are likely to be correlated with selective constraints on the protein, both between codons within a gene, as previously suggested, and also between genes within a genome...

..We argue that endogenous genetic barriers are often more likely than local adaptation to explain the majority of Fst-outlying loci observed in genome scan approaches - even when these are correlated to environmental variables...

..The present dataset also supports previous reports of partial spawning asynchrony...

..More generally, we suggest that comparative neutrality tests based on discrepancies among marker types have to be applied with caution when the presence of semi-permeable genetic barriers to gene exchange is suspected...

..Nevertheless, neglecting mutational load may to some extent obscure the estimations of selective parameters based either on artificial F1 crosses or on cline characteristics...

..We also provided evidence for a recent migratory 'short-cut' connecting M. edulis-like populations of the Charente patch to an external M. edulis population in Normandy and thought to reflect artificial transfer of spat for aquaculture...

..Moreover, the main origin of associative overdominance is random variation in individual inbreeding whereas physical linkage has little effect...

..Furthermore, they show that assortative mating through gamete preference, as already demonstrated for sea urchins, may play a role in speciation processes taking place in the sea...

..These results, together with previous reports, suggest that GC-biased gene conversion has influenced base composition evolution in Drosophila and explain the correlation between intron and exon GC content...

..balancing) remains unclear. This study concurs with previous reports of an effect of slight selection on AMP genes evolution in other invertebrates, although selection does not necessarily act on the mature peptides...

..The analysis of several Drosophila data sets suggests that approximately 25% +/- 20% of amino acid substitutions were driven by positive selection in the divergence between D. simulans and D. yakuba...

..All sequences have been incorporated into a publicly available database and form the basis for subsequent microarray design, SNP detection and polymorphism analysis, and the placement of novel markers on genetic linkage maps...

..We argue that the Goldman-Yang method is misleading in this context and conclude that methods that rely on a mutational-opportunity definition of a site should be used with caution...