1988/10/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
Other primates, such as chimpanzees and gorillas, copulate behind. Our ancestors passed behind at a point of evolution.
Herpes virus (RSV) has two forms in humans and one in monkeys. In humans, the HSV-1 virus is usually transmitted by kisses and genital HSV-2 virus. This may be due to their copulation position. Humans face sexual activity and genital contact and the general are fairly common actions. However, in the subsequent exercise it is difficult to kiss. Monkeys rarely kiss.
With the change to the frontal position, oral and genital transmission differed and the virus acquired two forms.
The time when the virus takes both forms was when our ancestors changed their position of copulation. Glenn Gentry, of the University of Mississippi, and his friends, have calculated the time when this occurred (the creation of two HSV viruses), taking into account the average rate of protein variation. The figure reached has been 10.7 million years.