The recruitment method may also imply selection bias towards 'especially motivated' students regarding their participation rate in examined courses or regarding their mobility.
This may imply that selection favouring the accumulation of non-synonymous substitutions within a lineage also favours the accumulation of synonymous substitutions.
The latter of these raises the possibility than the presence of an apparent homonym within a protein may imply positive selection within the family to which that protein belongs, and which may be detectable using appropriate methods (Yang, 1997; Anisimova and Yang, 2007).
Considering that metallicolous populations are presumed to evolve from non-metallicolous populations, this evidence may imply that selection for Cu tolerance in C. communis has been greater than in R. acetosa, although present-day levels of Cu tolerance in metallicolous populations are lower in R. acetosa.
Our results provide strong evidence that the majority of olive trees in the study are grafted, that the large majority of scions belong to a single ancient cultivar containing somatic mutations, and that the widespread occurrence of one sucker genotype may imply rootstock selection.
Although this may imply a study selection bias, we pre-specified the study selection criteria, thus minimising such bias.
Despite the fact that we provided a detailed follow-up of all consecutively treated patients this analysis may imply an operative selection bias.
These findings are particularly relevant to the observation of consistently higher codon bias of X-linked genes in D. melanogaster [ 30- 32] and may imply that natural selection might be more efficient at X-linked loci in general.
Significant difference between the levels of divergence in the gene segment regions and intergenic region may imply difference in selection pressure on these regions and the functional importance of these IGHV gene segments.
