The change in the composition of species in the community over time is the best answer
Genetic engineering is the process of manipulating the genes and therfor the traits of an organism
we already genetically engineer our plants so they are stonger, faster, and produce better (better looking, better tasting, etc) fruit/food.
we might possible be able to genetically engineer humand or babies to controll the traits we want (do you want your baby to be good at this)
basically genetic engineering is normally used to change theh current state of something so that it is more suited for the job that you intend for it
Relative dating to determine the age of rocks and fossils. Geologists have established a set of principles that can be applied to sedimentary and volcanicrocks that are exposed at the Earth's surface to determine the relative agesof geological events preserved in therock record.