Thanks for your prompt replies! My interest was in the way DNA is used to conclusively identify criminals, and then I got to wondering why, if it is so specific, do we not reproduce ourselves identically. If I understand
"Meiosis is more than merely choosing 23 haploid chromosomes. There is also a process called "crossover", where homologous DNA is swapped between DNA strands. giving far more combinations of DNA inside of the chromosomes, giving a greater variety of genes than even the parents had."
correctly, our end product selves are a result of these combinations in sub-sets of the DNA.