The basic material of chromosomes, which carries the hereditary instructions (the blueprint) which determine the formation of all living organisms. Genes the organizers of inheritance are composed of DNA. Analysis of the DNA of different primate groups has been used to determine the evolutionary line of modern humans. DNA techniques have also been used to show how long various regional human populations have been separated from each other. DNA analysis of blood residue both human and animal on prehistoric tools and weapons may provide information on the evolutionary relationships of a range of animal species and between prehistoric and modern humans.