Selection pressure at 165th and 276th residues of our blaTEM-1 like, blaTEM-169 and blaTEM-190 proteins indicated positive selection pressures during natural evolution of these variants.
That same-sex marriage could go from its preliminary draft of "diagnosable" to the final edit of "so what?" must indicate some positive evolution on the part of the larger human consciousness.
The selection pattern was characterized by the ratio of Ka to Ks substitution, in which Ka/Ks > 1 indicates positive selection or Darwinian adaptive evolution, Ka/Ks < 1 indicates purifying or stabilizing selection, and Ka/Ks = 1 indicates neutral evolution [ 61].
These results indicate positive selection during HOTAIR's evolution.
Purifying selection is indicated by ω <1, whereas ω =1 implies neutral evolution and ω >1 indicates positive selection [ 33].
A dN/dS (also known as Ka/Ks) ratio >1, <1 and = 1 indicates positive, negative, or purifying selection, and neutral evolution, respectively [ 32].
Additionally, as adaptive evolution is likely to act on a small subset of amino acid residues and hence averages of substitution rates across the gene may not strictly indicate positive selection, HGGs were scanned for adaptive evolution using codon-based substitution models that allow ω to vary among sites, with the parameters of the model estimated using maximum likelihood.
In this statistical approach, an ω < 1 indicates the action of purifying selection (i.e., a selective constraint against mutations that negatively impact the function of the protein); ω = 1 is consistent with neutral evolution, and ω > 1 indicates positive Darwinian selection (i.e., favoring the fixation of beneficial amino acid changes) [ 49].
A Ka/Ks ratio < 1 indicates purifying selection, Ka/Ks = 1 suggests neutral evolution, and Ka/Ks > 1 indicates positive selection.
An ω-value > 1 indicates positive selection, ω < 1, purifying selection and neutral evolution when ω = 1.
We considered the two lower rate categories as representing purifying selection and (nearly) neutral evolution respectively, and the two higher rate categories as indicating positive selection.
