Rollable tongue = genes are from...

Factual Questions
1

Not sure how to describe this to someone who has no idea what I’m on about but I’ll try:

Some people can roll their tongues into a tube and some can’t ( along their mouth front-back axis).
I remember being told that this was something to do with where their ancestry is from,but have no idea by who or any cite.
This is the kind of thing I remember:

Celtic people - or people with ancestry in the UK - can roll their tongues, whereas people with ancestry from the continent (Roman? Norse etc…) cannot.

Truth or fiction?

2

Fiction — because I know of a counter-example: these identical twins. One of them can roll her tongue, and the other cannot.

3

Probably because I wasn’t paying attention and can’t remember details this is useless but I know we were taught at school that tongue rolling was a genetic thing.

I’m a tongue roller and so are my parents and brother…my child is a non tongue roller (FREAK!! :D)

4

If tongue rolling is genetic, why couldn’t identical twins either both roll or both not.

:confused:
FTR, I can roll my tongue, and rotate it 360 degrees (180 either way) :smiley: :cool:

5

I haven’t (so far) found anything in the article about the twins rolling their tongues. We were taught in Physiology and Anatomy class that this is a genetic trait. I have Celtic heritage and I cannot roll my tongue. It infuriates me that I can’t roll my tongue. I believe that NOT being able to roll the tonge is a recessive trait.
As I remember from school a pair of truly identical twins would have all the same recessive and dominant traits. HOWEVER, twins can LOOK identical and still be fraternal. They do have the same parents and some siblings have a remarkable resemblance without being identical twins.

http://www.geneblack.com

6

It was on the program itself when it aired. After citing the many uncanny similarities between them, they cited a few differences, and this was one. Both girls stood side by side and stuck out their tongues. One could roll, and the other couldn’t. The reference was just so you could know who they are. You can contact the producers via the link for verification.

7

I can turn my tongue over. My children can as well. Try it - stick your tongue out, and turn it over.

8

I’ve always heard it’s a genetic trait, but I’ve never actually seen evidence or a citation, now that I think about it. (Note to self: whenever anyone tells you anything, loudly yell “Cite?” in their face.)

However, genetics is complex. Genetics plays a strong role in developing schizophrenia, for instance, and yet in many cases a person may develop the disease while their identical twin doesn’t. Most things aren’t subject to a 100%, double-your-money-back guarantee when it comes to genetics; perhaps it’s more accurate to say that there is a genetic trait that makes it easier (or more difficult) to role your tongue, or a genetic trait whose presence (or absence, as the case may be) makes it impossible to do so, without guaranteeing the ability for those who lack (or possess) the gene.

Just WAGs, obviously, but it’s still reasonable to say it’s a genetic trait even if in some cases it doesn’t behave in a perfectly clear manner.

9

No one yells “Cite!” in my face!

In A History of Genetics (Harper & Row, 1965), Alfred Sturtevant, wrote: {"It is important that suspected cases of Mendelian inheritance in man be recorded, so that they may be checked by other workers and, if valid, may be incorporated in studies of possible linkage and of anthropological questions. There is an unfortunate tendency, however, to accept cases when the evidence is so weak that it would not be conisdered conclusive for any other organism other than man. About 70 percent of people of European ancestory are able to roll up the lateral edges of the tongue (note boy on right in picture), while the remaining 30 percent are unable to do so (note girl on left in picture). In 1940 (Proc. Nat. Acad. Sci. 26: 100-102, 1940), I suggested that this difference is due to a single pair of genes (sic) (the ability being dominant), though it was clear that a few people were able to learn to do it and that there were a few discordant pedigrees.

In 1952, Matlock (“Identical twins discordant in tongue-rolling.” J. Hered., 43:24) concluded that identical twins don’t always share tongue-rolling.

N. G. Martin (J. of Heredity 66:179-180, 1975) found that identical twins are no more likely to share tongue-rolling than are fraternal twins. 8 of 28 MZ twins (29%) were discordant for tongue rolling (one could and one couldn’t) and a similar percentage (32% or 6 of 19) of DZ twins were also discordant.

In 1982, Cruz-Gonzalez, studying Thessaloniki Greeks, established that dry ear wax and attached ear lobes are recessive traits in that population, but the genetic basis for tongue-rolling was muddier.

In 1983, Katalin Forrai [Hungary. Sorry, cite not legible] found no genetic basis for tongue-curling – or “hand-clasping” or “arm-folding”. The latter traits are good serach terms for further research on the subject of such traits, e.g Reise, M “The genetics of hand-clasping a review and a familial study” Ann. Hum. Bio. 26:39 - 48 (Vol 26 No. 1 Jan 1, 1999)

The National Center for Genome Research lists it with a question mark: “? autosomal dominant”

And now you know WHY no one yells “Cite!” in my face

10

Well I was hoping someone would call cite! on my little admission:

Beat you to it CBCD. :stuck_out_tongue:

I wouldn’t mind providing a “cite” to a nice girl, maybe after a few glasses of wine. :smiley:

11

If its recessive that means if both parents can’t do it, the kids can’t either, right?

Just curious, as it’s been way too many years since I’ve dealt with simple genetics.

For the record: In our family of four, everyone but my mother can roll their tongue and everyone can turn it over. I can only turn it over one direction, however.

12

Nope, just means it’s not terribly likely. The kid would have to get the recessive version of the gene from both parents for it to be expressed. Assuming that there is only one gene involved (not necessarily a valid assumption, but it makes the math easier), look at it this way:

Upper-case letters - father’s contribution
Lower-case letters - mother’s contribution
D or d - dominant gene
R or r - recessive gene

Father is D-R, mother is d-r
An offspring will get one gene from each parent.
25% chance of a D-d mix - no recessive trait expressed
25% chance of a D-r mix - no recessive trait expressed
25% chance of a R-d mix - no recessive trait expressed
25% chance of a R-r mix - recessive trait is expressed

13

Gah, didn’t think of this before I hit Submit - that’s assuming that both parents are “carriers” of the recessive gene. If either parent does not carry it, while the other does, their children will not express that recessive condition as it will not be possible for them to have two copies of the recessive gene. Either mom or dad was only capable of giving them a dominant gene.

(Again, this is excluding mutation, effects that other genes might have on the trait, etc.)

14

Both my parents can roll their tongue but I can’t.

15

My daughter can do this.
Her mother nor I can not do this ever.

Salaam. A

16

That’s odd…neither can the mailman!

:wink:

17

Ahhhh, but what about the milkman?
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Better check the window cleaner as well. :smiley:

18

I have suddenly discovered the real reason my parents moved house. :smiley:

19

:wink:

20

LMAO. :smiley: