As I studied Biological Anthropology today I came across this, which I found particularly interesting: (This is found within the chapter on gene flow and genetic variation).
“Studies of the genetics of human and other populations have generally concluded that despite our long-standing belief that inbreeding, or reproduction between close kin, is always bad for the health of a population, very limited amounts of gene flow can eliminate the harmful effects of inbreeding. A study of rhesus macaque monkeys conducted in the mountains of Pakistan showed only limited migration between breeding groups. Nonetheless, very limited gene flow from males who immigrated to the valley where the study was conducted were enough to maintain high levels of genetic diversity (Melnic and Hoelzer, 1996). Studies such as this do not imply that inbreeding is normal and healthy, only that a low level of immigration apparently can offset its harmful effects in a population.”