The phrase "active selection pressure" is correct and usable in written English.
It can be used in discussions related to evolutionary biology, ecology, or any context where natural selection is being described.
Example: "In this environment, the active selection pressure has led to the development of traits that enhance survival."
Alternatives: "intense selection pressure" or "strong selection pressure".
Moreover, even if the coding sequences seem not to have been nonfunctionalized, the regulatory regions might have mutations because duplicated genes are considered to be under active selection pressure owing to energy constraints on gene expression [ 50].
Conversely, the reduction in the frequency of the common deletion in liver tumours indicates that there is an active selection pressure against the presence of mtDNA with large deletions, or more controversially that a population of liver cells do not undergo the typical ageing response and subsequently form the liver tumour.
One reasonable explanation is that the duplication events during the evolution of these miRNA families in Brachypodium are less active or the selection pressure on duplicated miRNAs is higher than that in rice and Populus.
Excessive utilization of non-degradable antibiotics by human patients or in farm animals might lead to accumulation in the water compartment and subsequently to the promotion of resistance development when wide areas containing relevant bacteria have sufficient concentrations of active antibiotics leading to a constant selection pressure on the bacteria.
This would imply that the retroposon acquired an active promoter and has been subjected to selection pressure.
Homogeneity of the VSG coat expressed was ensured by maintaining trypanosome transfectants with drug markers in the active VSG expression site on the appropriate drug selection pressure to prevent switches to different VSG expression sites.
Viral populations are dynamic and evolve under positive selection pressure.
The distribution of hω residues in KTTs, consistent with alignment results that suggest highly positive Darwinian selection pressure, often focuses on the biologically active region that usually interacts with their ligands.
As non-synonymous changes are more likely to be deleterious, under negative or purifying selection pressure, these substitutions were eliminated in functionally active proteins, which may have provided a steady protein complement for insects [ 28].
Pseudogenes, especially retrotransposed pseudogenes lacking active promoters, represent putatively unconstrained sequences which are accumulating variations due to the lack of selection pressure [ 27, 28].
However, the transposition of an isolated ESAG7 copy into an active expression site (without ESAG6 and 5) has been reported under in vitro drug and serum selection pressure [38].
