I love to study genetics. Okay, I love it to a point. It can be hard to follow all the single nucleotide polymorphisms on such and such gene, leading to a certain particular allele. But when I take the time to understand it, I’m amazed at how complex and unique God made our bodies.
As I age, I become more interested in the genetics of hair because my hair has gone through some changes in my lifetime. I was born with slightly wavy hair (my mom had wavy hair and my dad had curly hair) that went mostly straight in my adult years. But things changed when I got pregnant with my first child. My hair went curly and I had no idea how to handle it. It became a big, dry mass of hair, somewhat similar to a bee hive.
For years I worked with it and finally got control of it. I came to love my curls. Now that I’m done with having kids (for 7 years now) my hair has started to relax a little. It’s returning to its original wavy state and it makes me sad, but it has also made me delve into the genetics of curly hair.
Did you know curly hair is dominant? I think most people are surprised to hear that because it seems like more people have straight hair (45% of Caucasians). But this is in part based on what we define as curly.
True curly hair has both copies of the dominant gene for curly hair (C), or in genetic terms CC, and comprises only 15% of the Caucasian population. The 45% of people who have straight hair have two recessive copies of the straight gene, in genetic terms ss. The other 40% of Caucasians have wavy hair, genetically shown as Cs, because hair type is an example of incomplete dominance. Incomplete dominance means that when individuals have a dominant gene and a recessive gene, their hair type will not be expressed by only the dominant gene, but instead will be a mixture of the two.
If we include wavy haired people in our assessment of curly haired people, both segments add up to 55% and it’s easy to see how the gene for curly hair is dominant.
In 2009, scientists discovered the gene they believe is responsible for curly hair—trichohyalin. You won’t remember that (and neither will I), but every time you style your hair, think of how many complicated sets of genes are at work in you right now. God designed you Himself, even down to the multitude of hairs on your head.
I wouldn’t be able to say it any better than the way singer and song writer, Jonny Diaz, put it in his song More Beautiful You:
And you were made with such care, your skin, your body and your hair
Are perfect just the way they are
There could never be a more beautiful you
Don’t buy the lies, disguises and hoops, they make you jump through
You were made to fill a purpose that only you could do
So there could never be a more beautiful you
References: http://www.gbhealthwatch.com/Trait-Hair-Curl.php, http://genetics.thetech.org/ask/ask45, http://www.telegraph.co.uk/news/science/science-news/6751910/Curly-hair-gene-discovered-by-scientists.html, http://phys.org/news/2009-11-gene-curly-hair.html
Photo Credit: First photo: I have no idea, probably my dad. Second photo by Kinsey Christin.