Roll it, flip it, fold it and even mold it into a squiggle.
Your tongue can be an acrobat, regardless of whether your parents are capable
of the same tricks.
Every semester, John McDonald, an evolutionary biologist at
the University of Delaware, asks his undergraduate students the following
question: How many of you were taught in biology class that rolling the tongue
is a genetic trait?
Most of the students raise their hands. They're wrong.
In 1940, the prominent geneticist Alfred Sturtevant
published a paper saying the ability to roll one’s tongue is based on a
dominant gene. In 1952, Philip Matlock disproved Sturtevant’s findings,
demonstrating that seven out of 33 identical twins didn’t share their sibling’s
gift. If rolling the tongue was genetic, then identical twins would share the
trait. Sturtevant later acknowledged his mistake.
“I am embarrassed to see it listed in some current works as
an established Mendelian case,” he wrote in 1965 in his book, “A History of
Genetics.” Yet, McDonald says, the myth is still taught in science textbooks
and classrooms. See this and this, for example.
Don’t be discouraged if you aren’t a member of the
tongue-rolling elite — some can train their tongues to obey. In fact, one of
McDonald’s undergraduate students conducted a small study asking 10
non-tongue-rolling participants to try rolling their tongue each day. After a
week of practice, one participant achieved a successful tongue roll.
This doesn’t mean tongue rolling has no genetic “influence,”
McDonald says. More than one gene could contribute to tongue-rolling abilities.
Perhaps the same genes that determine the tongue’s length or muscle tone are
involved. But there isn’t a single dominant gene that’s responsible.
While you may think this myth is harmless, McDonald says
he’s received emails from kids who don’t share the tongue-rolling status of
their parents. Are my parents really my parents, they want to know? He quickly
puts their fears to rest. If mom and dad can’t roll their tongues, but you can,
don’t worry — chances are you’re still their kid.
This is so interesting considering I was also taught that it is a hereditary trait! I wonder what are the reasons behind some people being able to roll theirs while others cannot.
ReplyDeleteIts funny how some children of parents who didn't share the same "tongue-rolling status" as their parents began to question whether or not they were really related. It sounds like they immediately bypassed all of the other obvious things that prove that they are related. It reminded me of hypochondria in a way.
ReplyDeleteI remember learning in high school that this trait is inherited. It's funny how it was discovered that this trait wasn't genetic back in the 1960's but people still teach that it is in schools today.
ReplyDelete