Re: Can one identical twin can roll their tongue and the other can't?

This actually has to do with the muscles of the tongue. The tongue has 
different groups of muscles and the group in the very front of the tongue 
are responsible for this. If the muscles are very flexible than a person 
can roll their tongue, if not than they can't. So although the twins are 
very much alike this is something that can differ. Its more like doing a 
split than being genetically alike. I hope that helps with your class 
discussion.