the first living organism on earth was probably a(n) ___ because the fossil remnants indicate a single-celled prokaryote.

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).

other information encoded in your genes might distinguish you from the others in the group