The world's top scientists have joined forces to call for "evidence-based" teaching of evolution in schools.
A statement signed by 67 national science academies says evidence on the origins of life is being "concealed, denied, or confused" in some classes.
It lists key facts on evolution that "scientific evidence has never contradicted".
These include the formation of Earth 4.5 billion years ago, and the onset of life at least 2.5 billion years ago.
"In some countries, the simple theory of evolution is denied in the teaching of children in schools," according to the scientists.