By the year 2010, 17.8 million youths aged 16-19 will work, up from 16 million in 2000, according to government forecasts. Young workers suffer a disproportionate share of injuries and fatalities, especially in the first year on the job. In 2006, 30 youths under 18 died from work-related injuries.
A mutation may or may not affect the amino acid sequence. A mutation may or may not affect the phenotype. Some specific mutations in a gene may have more adverse affects than other mutations in the same gene. A mutation is not necessarily bad. It may even be good. A mutation may enhance or positively change the function of the protein produced by the gene.
In most cases, such changes are neutral and have no effect or they are deleterious and cause harm, but occasionally a mutation can improve an organism's chance of surviving and of passing the beneficial change on to its descendants. Mutations are the necessary raw material of evolution. Mutations can be caused by many factors including environmental insults such as radiation and mutagenic chemicals. Mutations are sometimes attributed to random chance events.