It is the very modern catchphrase of Homer Simpson. But 'Doh!' or a version of it may have prehistoric origins.
Research suggests that 'Duh' would have been one of the first words spoken by humans.
It is thought the shape and mechanics of the mouth, throat and other parts of the vocal tract of our ancestors from one million years ago would have allowed them to speak - but not a lot.
The mouth, tongue and throat are mainly made of soft tissue and so there is little evidence of them in the fossil record. But there is one bone in the vocal tract - the hyoid - and Dr Bart de Boer, of the University of Amsterdam, began studying it.
In apes the hyoid attaches to a large pouch called an air sac, which shrank as modern man evolved meaning more complex words could be formed, reports New Scientist.
