top 3 ideas based on affordability. include a description of the general costs of this plan and why it is less expensive than others.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

it should be d) transitional fossils.

they show the gradualism of evolution throughout a period of time