to be one of the zoonotic origins of HIV/AIDS. The SIV or Simian immunodeficiency virus that infects them is similar to a certain strain of HIV-1. The HIV-1 virus exhibits phylogeographic clustering, which is due to large rivers. This clustering allows pinpointing the probable geographic origins of two of the human virus clades. In the southern part of Cameroon, the populations of western lowland gorillas have had examinations of their feces. Out of 2,934 gorilla samples, 70 reacted with at least one HIV-1 antigen. These samples came from four field sites, all located in southern Cameroon. The origin of AIDS has been linked to a virus known to infect more than 40 species of nonhuman primates in Africa. HIV-1, is composed of four phylogenetic lineages, which at some point in time have independently gone through cross-species transmission of the SIV (simian immunodeficiency virus). The simian immunodeficiency virus infected various African primates such as gorillas and chimpanzees. Disease has also been a factor in the survival of the western lowland gorilla. The Ebola epizootic in western and central Africa has caused more than 90% mortality rate in western lowland gorillas. From 2003–2004, two epizootics infected the western lowland gorilla, which caused two-thirds of their population to disappear. The outbreak was monitored in the Republic of Congo by Magdalena Bermejo and other field-based primatologists, as it also spread to humans through contact with bushmeat. The catastrophe led the World Conservation Union to designate the western lowland gorilla a critically endangered species. Malaria is also an issue that has been arising for the western lowland gorillas. Out of 51 faecal samples from habituated individuals, 25 were shown to have Plasmodium DNA. Laverania, which is a subgenus of the parasitic protozoan genus Plasmodium, was found in these studies. Varying exposure to different Anopheles mosquitoes transmitting Plasmodium species is known to be the origin of malaria in western lowland gorillas. Wild western lowland gorillas are known to consume the seeds of the "grains of paradise" plant, apparently conferring healthy cardiovascular conditions from their consumption—the occasionally poor cardiovascular health of lowland gorillas in zoos has been postulated to be due to the lack of availability of the Aframomum seeds in zoo gorillas' diets. Adult male gorillas are prone to fibrosing cardiomyopathy, a degenerative heart disease. See also List of individual apes Cross River gorilla Mefou National Park References External links Western Lowland Gorilla Conservation in Gabon: