"what's important to me is the fruit of the land in kalahari," she says. "in the resettlement camps, everything is about money," she says. "if you don't have money, people end up stealing to survive." >> reporter: professor maitseo bolaane is the director of the san research center, a small office at the university of botswana in gaborone. she believes the san people are a resource that can be used for the good of the kalahari reserve. >> the people themselves are monuments. they can contribute their knowledge system in the utilization of the resources within the central kalahari game reserve. >> reporter: inside the c.k.g.r., those small communities hold on, numbers dwindling every year, living in the hope that others will be able to return. for now, it is only them, dancing in the desert under the kalahari stars. for the newshour, i'm martin seemungal in the central kalahari. >> brangham: on this independence day, many americans will no doubt be enjoying a beer or two. one of the essential ingredients in beer is yeast. but for 600 years, only two species