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AIDS stands for acquired immune deficiency syndrome. It is caused by one of two “retroviruses”, HIVE 1 or HIVE 2, also known as human immunodeficiency virus. There are several viruses that are similar to these, including SIVA, also known as simian immunodeficiency virus; however ‘this disease does not seem to cause any diseases” (Sharp 1999). This article studies the very detailed “sequence diversity and provides a model in studying the molecular evolution”. (Sharp 1 999) These results pertain to the origin of the AIDS epidemic. HIVE and SIVA are a part of the lentils family of retroviruses.
In all retroviruses the disease “contains two copies of an RNA genome and encodes three major genes gag, POI, and envy’ (Sharp 1999). In this study, it was discovered that the “polyethylene relationships among the viruses show very little correspondence with the polyethylene relationships of their hosts. This means that the viruses are the subject of several cross- species transmissions” (Sharp 1999). HIVE and SIVA are not closely related. HIVE-I is closely related to a virus found in chimpanzees and HIVE-2 is closely elated to SIVA from soot manganese.
SIVA has been found in African green monkeys which may have existed more than a million years ago. Humans are in fact infected with these diseases. HIVE-2 first appeared in individuals from West Africa. It seems that HIVE-2 was passed along to humans since they kept these monkeys (soot manganese) as pets. There are no clear results as to how HIVE-I has infected humans yet. However, since “SIVA cap is closely related to HIVE-I , it is assumed that HIVE-I is the result of the cross-species remission from chimpanzees” (Sharp 1999).
The viruses of HIVE-I fall into two categories, M and O. M viruses are the most numerous and most geographically widespread, while O contains viruses isolated from individuals from central Africa. It was concluded in this study that HIVE-I groups M and O came from two different cross-species groups. The Hips have a complex sequence diversity, “reflecting a rapid rate of evolution caused by two features of the viral replicate enzyme, reverse transcripts” (Sharp 1999).