Red hair is a recessive trait caused when a person has two copies of the mutated MC1R gene on their 16th chromosomes. Only 1-2% of the global population are red heads.

This trait is among one of the most common features on earth and is thought to be the original hair color of humans. Black and brown hair are found in all people of all backgrounds and ethnicities, ranging from Asian to African to Latin American to European.

Brown eyes are a dominant trait. Over half of the world's population has brown eyes, as the majority of people from Asia and Africa have this eye color.

Tone deafness is actually a dominant gene and the ability to carry a tune expertly is recessive. However, the majority of people can still carry a very basic tune.

Curly hair is a dominant trait, however, it is more prevalent in some populations than others. For example, it is less common among Caucasians.

This is a common vision problem, in which people can see things from afar, but not so well up close. It's thought that over half of Americans are farsighted, even if it is only to a small degree.

It's thought that about 30% of Americans are farsighted to some degree. This common condition makes objects up close appear clearly, but far away objects appear blurry.

A widow's peak is a V-shaped patch of hair where the hairline meets the forehead. It gets its name from the old myth that a woman with one would outlive her husband.

While technically a medical deformity, dimples have been considered signs of luck and beauty in cultures around the world for centuries. About a fifth of the world's population has them.

This dominant trait only becomes visible after sunlight exposure. No baby is born with freckles.

Those with cleft chins have inherited a recessive gene. These genes are more common in European populations.

While it is thought that our species originally had straight hair, we evolved into curls. The trichohyalin gene is the one responsible for creating curly hair.

Most of the world's population carries this gene. It is estimated that about 90% of the world is right-handed.

It's estimated that only about 10% of the entire human population has this gene and is left-handed. Humans have been this way for thousands of years.

When it comes to human blood, there are A, B and O genes. A and B are dominant, while O is recessive.

This recessive trait is actually the result of a genetic mutation. It's the rarest eye color on earth, as only about 2% of the global population has green eyes.

This transcription error on the 16th chromosome results in extra eyelashes growing in the waterline of the eye. This is a dominant trait, meaning that all it takes is one parent with it to virtually guarantee a child will have it too.

Despite the vast majority of people having 5 fingers, this trait is actually recessive, while having 6 fingers is dominant. It's thought that since 5 fingers were considered more attractive, it led to more of these people finding partners, which made this recessive trait more common.

This recessive genetic combination is relatively rare globally, but prevalent in certain groups. While less than 10% of the world's whole population has blue eyes, in the European country of Estonia, over 90% of the people are blue-eyed.

Studies show that 15% of people are not allergic to poison ivy. These people are actually displaying a dominant genetic trait.

Shortness is a dominant gene and tallness is recessive. This recessive gene is more common in women and less common in men.

Type O blood is a universal donor, meaning that it can coexist with any other blood type. While it's a recessive gene, it is not rare, as almost half of all African Americans have it.

Hairy hands are a dominant trait, however, they are more or less prevalent in some populations. While African Americans often have hairier knuckles, Eskimoes have almost none.

This recessive trait affects one in 12 men worldwide in some form, and many others are carriers. It affects almost 5% of the global population.

Thin lips are recessive while fuller lips are genetically dominant. Their prevalence varies by community.

Those who can roll their tongue by raising the sides together have inherited a dominant gene. Those who cannot do this have inherited a recessive gene.

Albinism is a recessive trait. This rare condition, in which melanin lacks in hair, skin and eyes, affects roughly 1 in 20,000 people globally.

Congenital deafness is recessive, which is why one or two deaf biological parents does not guarantee that a child will also be deaf. About 70 million deaf people around the world speak sign language as their first language.

People who can bend their pinkie fingers inward toward their fourth finger are actually expressing a dominant genetic trait. This dominant gene causes the distal section of that finger to bend.

Those with a cleft chin have a dominant gene. These without one have a recessive gene.

Body hair is a genetically dominant trait. However, the presence and distribution of body hair can differ between ethnicities.

Those with long eyelashes have a dominant trait. Those with short eyelashes have a recessive trait.

Broad noses are ultimately a dominant trait while narrow noses are recessive. However, average nose width can often vary by ethnicity.

Astigmatism is a dominant trait. If you have normal vision, you have a recessive genetic trait.

O blood types are comprised of recessive genes but are still the most common blood types in America. 38% of the population is O+ and 7% is O-.