Let's further define mutation as a heritable change in the genetic material. This point becomes important in multicellular organisms where we must distinguish between changes in gametes (germline mutations) and changes in body cells (somatic mutations).
Statistical significance relates to the question of whether or not the results of a statistical test meets an accepted criterion level. In psychology this level is typically the value of p < .05. The criteria of p < .05 was chosen to minimize the possibility of a Type I error, finding a significant difference when one does not exist. It does not protect us from Type II error, failure to find a difference when the difference does exist.
For the everyday meaning of significant, synonyms are large, important, big, meaningful etc. Statistical significance means that if, in the population from which the sample was randomly drawn the null hypothesis (e.g. âthat there is no differenceâ) was true, then it is unlikely that you would get a test statistic (e.g. t value) as extreme as the one you got in a sample the size of the one you have.