We use these results to prove the strong existence of the solutions of stochastic differential equations with singular (functional) drifts and also to prove the non-existence of strong solutions of some stochastic differential equations.
Species differences in sub-cellular localization may reflect non-functional neutral drift.
Although the overall functional significance of epigenetic drift remains to be established, a few instances of epigenetic drift causing silencing of key transcription factors have already been reported [ 5].
However, as in eukaryotic evolution, where new protein interactions compensate for random drift in functional complexes, 54 new protein design may of course adapt connectors for broader use.
A second pressing question relates to the functional consequences of epigenetic drift, since it would appear that the association between age-driven DNAm and gene expression changes is, at the very best, only marginal (18 , 25 55).
In neither of the two data sets did we observe a difference in p N / p S between the native AZ population and the introduced AL population, again suggesting that neither the introduction itself nor the exposure to the epizootic have considerably affected the drift of functional polymorphisms in the introduced AL population.
It is very likely that only a very small fraction of the age-associated epigenetic drift is of functional consequence, with the few functional changes ultimately affecting key transcriptional regulators, thus compromising stem cell differentiation (55) or predisposing cells to neoplastic transformation (74).
Whereas non-functional regions of the genome evolve mostly due to neutral drift (Kimura, 1983), functional regions are, for the most part, under negative selection, i.e. most mutations are deleterious.
Measured end points included, but were not limited to, total and population abundance, total and population biomass, relative abundance, taxa richness, Shannon diversity, trophic functional feeding group abundance and biomass, drift rate and density, drift richness, and drift Shannon diversity.
Through conversations in this language students can begin to consider the fact that many gene products have multiple functions, that gene duplication is essential for functional specialization, and that genetic drift is a key evolutionary mechanism (Aharoni et al., 2005; Copley, 2003; Lynch, 2007).
