Part of the show Cambridge Science Festival - Bioterrorism & Biological Weapons
Is there an evolutionary advantage to tongue-rolling ?
No one seems to know why some of us can roll our tongues (into a tube shape) and some of us can't !
For years it has been thought that tongue rolling is genetically inherited. This means that if both your parents carry the gene and can roll their tongue, you have a 3 in 4 chance of being able to roll your tongue too.
We don't know if there is an evolutionary advantage.
It may be that if a gene involved in tongue rolling is close to another important gene, they may be inherited together. (eg. people who have cystic fibrosis seem to have protection against salmonella, so there are lots of cystic fibrosis carriers in Europe).
Some scientists reckon you can learn to tongue roll with practice, but you need to carry the gene in order to succeed.
However, whether tongue rolling is genetically inherited at all, is now debated, as studies in 1975 in identical twins showed about 1/3 of them don't share the trait. Another study, in Spain, showed 67% women and 64% men can roll their tongues, whilst another more recent internet survey suggested up to 81% people might be able to perform the feat.
But, the long and the short of tongue rolling is: we don't know - maybe tongue rolling was important in our ancestors for eating, drinking or speaking!
I don't believe I have the ability, but I have wondered if there would be a linguistic benefit to rolling the tongue. Perhaps more flexibility in the tongue. What about whistling differences?