define. i.natural selection ii.genetic drift iii.organic evolution

(i) The process whereby organisms better adapted to their environment tend to survive and produce more offspring is called natural selection.

(ii) The process of change in the genetic composition of a population due to chance or random events rather than by natural selection, resulting in changes in allele frequencies over time is called genetic drift.

(iii) Organic evolution is the scientific process of identifying a genetic change in a species or within a group of species over an amount of time.