PRESS ASSOCIATION -- Scientists have gained fresh insight into how viruses such as Sars jump between species, which could help predict the emergence of future diseases.
Researchers have shown that viruses are better able to infect species that are closely related to their typical target species than those that are distantly related.
Scientists from the universities of Edinburgh and Cambridge looked at how relationships between species might determine the spread of a group of emerging diseases, known as RNA viruses, which includes HIV, Sars and flu.
Researchers infected more than 50 species of flies with three different viruses.
Their results showed that species closely related to a virus's usual target species were more susceptible than distantly related flies.
They also showed that groups of flies that were closely related were similarly susceptible to the same viruses.
The scientists' results suggest that when diseases make the leap to a distant species - such as bird flu infecting humans - they may then spread easily in species closely related to the new victim, regardless of how closely related these are to the original target species.
Ben Longdon, of the University of Edinburgh's School of Biological Sciences, who led the study, said: "Emerging diseases such as Sars, HIV and some types of flu have all got into humans from other species.
"Understanding how diseases jump between different species is essential if we want to predict the appearance of new diseases in the future."
The study, funded by the Biotechnology and Biological Sciences Research Council, Natural Environment Research Council, the Wellcome Trust and the Royal Society, was published in the journal PLoS Pathogens.