Distant relatives

According to the scientists, there may be a common ancestor to the viruses that cause AIDS, Ebola and influenza. Scientists say all the viruses use a very similar mechanism to enter the cells they infect. "The structure of this molecule shows that a widely dissimilar virus, a virus that everybody thought was different from the other group, ends up having, in fact, many similarities," said virologist Robert lamb, a member of the team at Howard Hughes Medical Institute at Northwestern University in Chicago, USA. "It suggests a common ancestor among all these viruses, where one would have thought they could not be related at all," he said.