Stratum 3 may well include several strata that were formed successively in a short period of time and that are no longer distinguishable simply because the levels of divergence between the X and Y sequences in these strata are very similar.
This was often because of high levels of divergence between D. melanogaster and the D. yakuba/ D. erecta clade.
The problem is known to be difficult because of the extent of divergence between this diverse group of gymnosperms and their closest phylogenetic relatives.
Because the estimated time of divergence between some of these species (e.g., M. musculus and R. norvegicus) and humans is essentially the same [ 31], we assumed that they marked the same time point in the evolutionary past.
The finding of microsynteny conservation between monocots and dicots species in chromosomal segments containing MIR169 gene copies together with bHLH and COL genes is remarkable because the estimated time of divergence between monocots and dicots is approximately 130 240 Ma (Wolfe et al. 1989; Jaillon et al. 2007).
Phylogenetic distance measures, which account for the phylogenetic relationship among the species, provide far more power because they exploit the degree of divergence between different sequences.
Because of the high level of divergence between the YLS and M. anisopliae, no useful alignments could be obtained for either orthologous introns or intergenic spacers, and further analysis of deletional biases was not possible.
To generate anti-HSPA2 rabbit polyclonal antibody, C-terminal peptide (NH2-SKLYQGGPGGGGSSGGPT), corresponding to amino acids 611 628 in the mouse HSPA2 sequence was selected because of the highest level of divergence between HSPAs amino acid sequence (Rosario et al. 1992; Scieglinska et al. 2008).
We then tested whether these LHR orthologs can also interact with D. melanogaster and D. simulans HP6, because HP6 has a much higher rate of divergence between D. melanogaster and D. simulans than HP1 (Table 1).
Because many scans for selection involve comparisons of divergence between "pairs" of species (usually in the form of the ratio of nonsynonymous to synonymous substitutions), they cannot polarize evolutionary change along individual lineages nor can they distinguish between positive selection and a relaxation of constraint for any but the most strongly selected genes.
This metric is tolerant of divergence between the sequenced strain and the reference because protein sequences diverge much more slowly than nucleotide sequences.
