A genetic mutation may have helped early humans fend off toxic fumes that wafted into the air from ancient cave fires, a team of researchers claim.
But if those offsetting factors are not so robust, he added, then the mutation may have "a very dramatic impact".
Emerging Expert Adaptive (key concepts only) "A mutation may have taken place that allowed a locust to be immune to DDT, this trait was then passed on.
The discovery, reported in the 13 November issue of Nature, demonstrates that a minor mutation may have the potential to split one species in two.
One implication of this realization is that recent mutation may have a greater influence on disease susceptibility or protection than is conferred by variations that arose in distant ancestors.
Mutation is standard among viruses, and according to two cell model studies published in the journal Cell in November, an Ebola mutation may have allowed the virus to infect humans more easily than the original.
Nevertheless, in a subgroup of patients, the presence of a deleterious mutation may have phenotypic consequences.
Our studies suggest that the Y302F mutation may have a similar function.
The differences may be attributable to allelic differences, or the canine mutation may have distinct tissue-specific consequences that sidestep cardiovascular and pulmonary effects.
Since the amino acid at NA-91 is not located in the DTD, the NA V91I mutation may have no direct effect on drug sensitivity of the virus.
The total floral organ number was also much lower in 'St Anne's' than in 'Malmaison', suggesting that the mutation may have an impact on floral meristem termination.
