The papers following explore aspects of these issues in more detail, with studies relevant to cancer, parasites, predator evolution, maintenance of genetic diversity, and adaptive mutation
The second way is a more gradual process of adaptive mutation
, whereby the capability of the virus to bind to human cells increases during subsequent infections of humans.
They cover, among other topics: radical enzymes in anaerobes, the structural and functional role of RNA in icosahedral virus assembly, virulence genes in the dimorphic fungi, the adaptive mutation
controversy, and multilocus sequence typing of bacteria.
The concept of adaptive mutation
leans heavily on the Lamarckian view.
Many scientists contend that dramatically increased rates of mutation are almost always bad for bacteria, while others believe the bacteria depend on adaptive mutation
to outlast the trials of harsh environments.
In a further extension of the accordion analogy, in addition to observing rapid gene expansion in the E3L-deficient strain of vaccinia, the researchers also observed that the virus contracted after acquiring an adaptive mutation
, swapping a beneficial mutation for a smaller genomic footprint.
Nevertheless, analyzing adaptive mutation
of the new pandemic (H1N1) 2009 virus is a priority so that researchers can evaluate the likelihood that viruses from other nonhuman species will further adapt to humans.
Our sequencing of CHIKV genomes confirmed spread of an Asian lineage strain from the Caribbean and suggested that although CHIKV has circulated in the Americas since 2013, no adaptive mutations
These analyses will provide insight into the diversity of H5N1 quasispecies and the molecular mechanisms of human adaptive mutations
Drugs that interfere with it thus could limit "the potential for development of drug resistance that can occur due to rapid adaptive mutations
of viral genomes," the scientists state.
The H7N9 virus acquires selective adaptive mutations
while moving across people, the report added.
Although apparently adaptive mutations
such as these arose in the past 10,000 years, some geneticists doubt that the agricultural revolution jump-started the pace of genetic evolution.