Genetics have come along way since this field first started out. Now, you can take a DNA sample at home and send it in to be tested for your family history and potential medical problems. On a more personal level, your genetics also determine the way that you look. You may have your mother’s dimples or your father’s oily skin. You could have blue eyes like a parent even though no one else in your family has them.
At the heart of these differences is your DNA. Dominant and recessive traits can determine the way that you look. While you may inherit both your mother’s brown eye trait and your father’s blue eye trait, the only eye color that actually appears in you is the one that is dominant.
How Do Your Genes Work?
Your DNA can determine how you look and even how you act. There is a gene known as the psychopathy gene that is present in most psychopaths. There is also a gene that has been found in everyone who has made it up Mount Everest and a different one found among Olympic weight lifters. While you still have the potential to be anything that you want, your genes can control a significant amount of who you are and what your potential is in life.
Your genes are like a code for who you are. They can determine your hair color, eye color and everything about you. When you are conceived, you receive a DNA copy from your mother and father. This means that you generally have two copies of most of your genes. While you may have differing copies of your eye color gene, the eye color that actually appears is the dominant one. A dominant gene is the one that actually appears in your person, while the recessive gene hangs back and can be passed along to your descendants. If you have a recessive gene like red hair or green eyes, the only way that you will actually have red hair or green eyes is if both parents pass along this recessive trait. Otherwise, a more dominant hair color or eye color will appear.
To gain a better understanding of how this works, let’s look at an example of green eyes and brown eyes. We will use a little “g” to show the green-eyed, recessive trait. A big “B” will be used to show the brown-eyed, dominant trait.
Now, your let’s assume that your mother has green eyes. To have green eyes, she has to have a “gg.” Since this gene is recessive, this is the only way that she could actually have green eyes appear. Now, let’s assume that your father carries “BB” from both parents passing on the brown eyed trait. This means that you could inherit only a B and a g from your parents. You would have brown eyes, but you would carry the green-eyed gene. If you marry someone with green eyes, your children could potentially have green eyes.
Now, let’s change up the example. Let’s assume your mother still has green eyes. Your father has brown eyes, but he carries the recessive gene. This means that your mother would be “gg” still, but your father would now be “Bg.” This means that you could inherit one of the following options:
Basically, you have a 50/50 chance of having green eyes or brown eyes. In all of these situations though, you would be a carrier for the green-eyed gene.
Now, a third and last example. Let’s assume that both of your parents have brown eyes, but they both carry the recessive gene for green eyes. This means that they are both “Bg.” This means you could inherit one of the following options:
In three of the above scenarios, you still get the brown-eyed gene, so you would have brown eyes. In one situation, you would have just “gg,” so you would have green eyes. Your chances of having green eyes are one out of four. You have a three out of four chance though of carrying the recessive green-eyed gene and passing it along to your children.
Common Dominant and Recessive Traits
Now, let’s look at some of the most common dominant and recessive traits.
1. Attached Earlobes
You can either have your earlobes attached to the side of your head or separated from it. Unattached earlobe genes are the dominant gene, while attached earlobes are recessive.
To have freckles, you only need to inherit one freckle gene from your parents. To not have freckles, you have to inherit no freckles from both of your parents.
3. Widow’s Peak
This gene contains two alleles. One is recessive for a straight hairline, and the other is dominant for a widow’s peak. The dominant trait is a widow’s peak, so you will have a widow’s peak if you inherit this trait from either of your parents.
Right handedness is generally dominant, while left handedness is recessive.
5. Tongue Rolling
Can you roll your tongue by raising both sides of the tongue together? If so, then you have inherited the dominant gene.
6. Crossing Your Thumbs
Interlock your fingers. Now, look at which thumb is on top of the other. If your left thumb is on top, you have inherited at least one of the dominant gene. If your right thumb is on top, then you inherited both of the recessive genes.
7. Curly Hair
Curly hair is generally considered a dominant gene, and straight hair is recessive.
Dimples are the tiny little indentations that happen when you smile. Dimples are considered the dominant gene, while not having dimples is the recessive gene.
9. Bent Pinkies
Can you bend your pinkie toward your fourth finger? If you can, then you have inherited the dominant version of the gene that allows your pinkie to bend.
10. Cleft Chin
A cleft chin is considered the dominant gene. Not having a cleft chin is from inheriting two of the recessive genes.