Skim coating weak concrete is only a temporary fix. Another option is to lay a thicker overlay and slow-dry the new surface. To slow-dry, cover the driveway with moist, breathable material. Keep the material wet to provide additional moisture for the concrete to absorb.
The two main sources of genetic variation are gene shuffling and  mutations. A mutation is a process wherein the structure of a gene  is altered.Edit. Share to: Blobbert. 37,033 Contributions. Answered.In Genetic Engineering.he 4 types of genetic variation are 1) mutation-is the mutation of a gene. this is really rare, most mutations are in the recessive trait so they are hidden by a dominant t â¦ rait. Most mutations have no effect but some can be harmful and very few have positive effects.
But then there is no longer any variation for further evolution. The possibility of continued evolution therefore is critically dependent on renewed variation. For a given population, there are three sources of variation: mutation, recombination, and immigration of genes.utations are the source of variation, but the process of mutation does not itself drive evolution. The rate of change in gene frequency from the mutation process is very low because spontaneous mutation rates are low (Table 24-9).