Purifying selection acts to prevent divergence of structure and function by selecting against extreme values of a trait, in contrast to directional selection, where a single phenotype is selected and therefore allele frequency shifts in one direction.
Pursuant of our original goal to correlate divergence of YbdB/YdiI homolog function with the divergence of structure, we now take an in-depth look at the homologs within the Enterobacteriaceae family.
The diversity and morphology of male genitalia have been well documented in many insect taxa [ 1- 7], and most evolutionary biologists agree that sexual selection is responsible for driving the frequent and rapid divergence of these structures [ 6, 8- 11].
This suggests that part of the evolutionary differentiation that occurred within these genera included divergence of the structure of the SigB-controlled regulons.
Little similarity in banding patterns was observed among or even within HSGs (Additional file 3), suggesting divergence of genome structure.
However, the significant pattern of divergence of intron structure between classes, and conservation within classes, adds further evidence for functional divergence among classes.
The divergence of exon/intron structure often plays a key role in the evolution of gene families.
Hi-C maps from liver cells of different species allowed us to ask how the evolutionary dynamics of CTCF correlate with conservation or divergence of domain structure.
This might be due to the greater extent of divergence of this structure between mice and men than other CNS regions, like the cerebellum and retina.
To close, we note that the mutational part of the Stress Model accounts for observed patterns of evolutionary divergence of protein structure and dynamics [ 21- 23].
