It is reasonable to assume that an attack to tubulins by drugs in tumors where BUB1 appears mutated may drift the tumor population towards extinction by exceeding the limits of mutation tolerance.
The origins of limits on mutation rates from above are perhaps harder to untangle.
The Balance feature was only selected in sensitivity analyses where the training dataset was truncated at the upper age-limit of mutation carriers.
A third gray-level feature, "Balance", was selected in sensitivity analyses in which the training dataset was truncated at the upper age-limit of mutation carriers.
Some admixtures of mutant cell line DNAs with normal control DNA samples were included to obtain some preliminary data on limits of mutation detection.
The upper (5.2 × 10-4) and lower (1.1 × 10-3) 95% confidence limits of mutation rate for nuclear microsatellite loci of plants [ 33] were used as reference.
In this respect, the limits of mutation detection techniques and the small number of breast/ovarian and site-specific ovarian cancer cases tested should be taken into account, together with the fact that most of the probands examined here were from families with only one case of ovarian cancer.
Nevertheless, their data suggest the existence of an upper limit of the mutation rate, beyond which negative clonal selection begins to limit survival of mutator clones.
For each set of observed frequencies, likelihoods were calculated under models with increasing numbers of mutations, up to a limit of six mutations per system (the limit being chosen on computational grounds).
Our result shows that in the limit of small mutation rate, the solution remains regular in the spatial variables and yet concentrates in the trait variable and forms a Dirac mass supported at the lowest diffusion rate.
An analytic calculation of evolutionary chromodynamics in finite populations is possible in the limit of small mutation rates [33], [34].
