A mutation can cause evolution of a population. When a parent with genes that is red in coloration to have offspring with a gene for black coloration, it more frequent in the population before the mutation. (I am going to use a fly for examples) In migration flies from a black population joins the red and makes the black color more frequent in the red fly population, before the black fly migration. A Genetic draft when flies are killed and has no offspring which making the next generation less. Genetic makeup cannot change unless there is a genetic variation in the population.
A mutation can cause evolution of a population. When a parent with genes that is red in coloration to have offspring with a gene for black coloration, it more frequent in the population before the mutation. (I am going to use a fly for examples) In migration flies from a black population joins the red and makes the black color more frequent in the red fly population, before the black fly migration. A Genetic draft when flies are killed and has no offspring which making the next generation less. Genetic makeup cannot change unless there is a genetic variation in the population.