Animal testing on non-human primates between the monkeys natural behaviors versus the behaviors expressed by the diazepam induced monkeys in thirteen different locations inside the maze. Scientist Barros and his colleagues created this model to allow the monkeys to roam a less confined environment and slightly eliminate outside factors that may induce stress. Many of the best-known allegations of abuse made by animal protection or animal rights groups against animal-testing facilities involve NHPs. The so-called "pit of despair" was used in experiments conducted on rhesus macaque monkeys during the 1970s by American comparative psychologist Harry Harlow at the University of Wisconsin–Madison.<ref name="Blum1994/95">Blum, Deborah. "The Monkey
Rhesus macaque The X chromosome has three times more rearrangements than other chromosomes. The macaque gained 1,358 genes by duplication. Triangulation of human, chimpanzee, and macaque sequences showed expansion of gene families in each species. The "PKFP" gene, important in sugar (fructose) metabolism, is expanded in macaques, possibly because of their high-fruit diet. So are genes for the olfactory receptor, cytochrome P450 (which degrades toxins), and CCL3L1-CCL4 (associated in humans with HIV susceptibility). Immune genes are expanded in macaques, relative to all four great ape species. The macaque genome has 33 major histocompatibility genes, three times those of human. This has clinical