I have just googled evolution and in the explanation it stated- organisms are believed to have developed, also it says- the theory of gradual evolution. I thought that evolution is now considered fact.
The words believed and theory to me seem to suggest that offically there is still some doubt or am I just being too perdantic.
Is the Oxford dictionary beyond reproach? Or just needs an update?
I presume that the Oxford dictioary is based on fact or am I mistaken.
Evolution is certainly accepted as fact by the scientific community, but there is still much doubt among laypeople. In America, almost 50% of the population believes the Earth is only 6,000 years old, for example. If I had to guess, that is why the Oxford dictionary phrased it the way they did. That, or the author of that particular definition had a personal bias.
The dictionary.com definition does not use that kind of language: http://dictionary.reference.com/browse/evolution?s=t
Also, the American Heritage dictionary provides a more assertive definition: http://science.yourdictionary.com/evolution
Remember: dictionaries do not establish what words mean. They only document how words are being used. So I wouldn't take it as the authoritative source for scientific definitions, but rather a guide to point you in the right direction. Also, remember that word choices like "believed" doesn't necessarily imply doubt. That's just how the author chose to phrase it ;)