|Genetic drift can be defined as a change in the frequency of allele that is random instead of being driven by selection pressures. According to Mendel law, alleles are randomly assorted into sex cells. When the offsprings reproduce, they can only transmit one of their trait which is inherited from their parents. Genetic drift causes number of changes in a population but only in a few generations, especially if the population is very little. Genetic drift also reduces the genetic variation in a population.
Open access to the scientific literature means the removal of barriers (including price barriers) from accessing scholarly work. There are two parallel roads towards open access: Open Access articles and self-archiving. Open Access articles are immediately, freely available on their Web site, a model mostly funded by charges paid by the author (usually through a research grant). The alternative for a researcher is self-archiving (i.e., to publish in a traditional journal, where only subscribers have immediate access, but to make the article available on their personal and/or institutional Web sites (including so-called repositories or archives)), which is a practice allowed by many scholarly journals.
Open Access raises practical and policy questions for scholars, publishers, funders, and policymakers alike, including what the return on investment is when paying an article processing fee to publish in an Open Access articles, or whether investments into institutional repositories should be made and whether self-archiving should be made mandatory, as contemplated by some funders.