It's genetic, isn't it?

Genetics is the study of how genes are inherited in a population. A scientist interested in genetics is a geneticist. If something is genetic, that means it is passed to you by your Mum and Dad. You inherit genes from your parents.

Genes control most aspects of human life, from eye colour to how fast you can run. There are some fun ways to demonstrate genetics in your own family.

Take tongue rolling. The ability to roll your tongue is what we call a dominant trait. If you have the gene for tongue rolling you will be able to roll your tongue.

Can you roll your tongue? No, not like this….

Like this!

Yes? You only need one copy of the gene to roll your tongue. It could have come from your mother or father, or you could have got a copy of the gene from both your mother and from your father, if they can both roll their tongues.

No? Then you didn’t get any copies of this gene from either your Mum or Dad. It doesn’t matter if you can’t roll your tongue; it’s completely normal. I can’t roll my tongue and I’m mostly normal!

Tongue rolling is a Mendelian genetic example. Gregor Mendel was a famous Austrian scientist who worked out inheritance using tall and short pea plants. Mendelian genetics demonstrates that our genes are inherited equally from each parent. You can draw out the inheritance pattern in your family for the gene for tongue rolling.

First, ask your Mum and Dad and brothers and sisters to roll their tongues. Observe who can and who can’t roll their tongue. Remember, you are looking for rolling your tongue into an ‘o’ shape, as shown above. Draw a simple diagram like the one below. If someone can roll their tongue, put ‘+’ and if not, put ‘-‘.

Can you tell who you got your ability to roll your tongue from? You can also ask grandparents, aunts, uncles and cousins to roll their tongues – it could make a fun family gathering, and is a little bit of science too.

If you would like a bit more detail, do have a look at my blog. I am very happy to answer questions.

Dr Lesley Beeton is an experienced life science researcher with a passion for talking and writing about science.