Let’s see who paid attention in science class. Most people know that our physical traits are determined by genes, and that our genetic material comes from our parents. Some genes are dominant, others recessive. Dominant genes are those most prominently displayed if present. Some of these dominant traits are prevalent enough to impact the physical makeup of humanity.
Conversely, dominant does not always mean common. There are times at which recessive genes are the norm. This list of dominant human genes focuses on dominant traits common in the majority of the population. Give it a look to see which of your genes are dominant and which recessive.
Everyone knows being right handed is kind of the norm. If you doubt that, think about how hard it was to get left-handed scissors in kindergarten. A whopping 70 to 90% of people are right handed, all because right-handedness is a seriously dominant gene. High five, righties!
The vast majority of people in the world have black or brown hair. These colors are genetically dominant to all other hair shades. More than half the US population has brown or black hair; in certain races and ethnicities, as much as 98% of people have dark hair.
Ability To Taste PTC
Phenylthiocarbamide, or PTC, is an organic sulfur compound rarely found outside laboratories. In 1931, American chemist Arthur Fox discovered that some people taste the extremely bitter PTC, and others don’t.
Various studies conducted worldwide show that the ability to taste PTC is a dominant trait. As many as 75% of Americans can taste PTC; in indigenous American populations, that number is as high as 98%. While this sounds like a relatively innocuous genetic trait, the ability to taste PTC is correlated to the ability to taste bitter things in general.
Many bitter things are also toxic, meaning the ability to taste PTC may be a dominant trait because those without the trait died eating toxins they couldn’t taste.
Did you know that one eye color dominates the rest to a startling degree? More than 55% of the global population has brown eyes. That means brown eyes account for more of the population than the other five colors – hazel, blue, green, silver, and amber – combined.
Free Ear Lobe
Maybe you’ve heard this before. High school science class, perhaps? If you look at earlobes, you’ll notice some are joined directly to the side of the head, while others swing free. These free ear lobes come from dominant genes, and are vastly more common than their attached counterparts.
While no definitive global study exists, it’s estimated that more than two thirds of the human population has free earlobes. In some countries and cultures, however, the split is more like 50/50.
Long lashes sure are lovely. They’re also a dominant trait. Studies show that in many races and ethnicities, including Caucasian and Japanese, long eyelashes are definitely the majority.
Getting pencil-thin eyebrows may be an enviable beauty feat for some, and that’s mainly because thin, fine eyebrows are in the minority. Why’s that? Well, as it turns out, thick eyebrows are a dominant trait.
Thankfully for our species, the unibrow is not a dominant trait.
Left Thumb Crossing
Put your hands together like you’re praying. Of, if you’d prefer, clasp them together, fingers intertwined. Either will do. Now, which thumb is on top? If it’s the left, you’re displaying the dominant gene, and you’re in the majority.
Studies have found that well over half the global population exhibits this trait, a random accident of genetics.
Left Arm Folded Over Right
Just as with fingers, the manner in which you cross your arms depends on your genes. In this case, the left arm folding over the right is dominant; more than half of individuals studied displayed left-over-right arm folding.
You might be thinking “aren’t all faces round?” Not if you’re a blockhead. Seriously, faces are categorized as either square or round, then subcategorized into a number of types.
Dimples are an irregular dominant. This means that, while most people who have dimples produce children with dimples, it isn’t always the case. Because of this irregularity, geneticists hypothesize that dimples come from more than one gene.
As with long eyelashes, many people seem to want a set of full, luscious lips. Lucky for them, broad lips are in fact dominant. Certain groups – those from hot climates – display this trait more commonly than others.
Thin lips and small nostrils help the body retain heat, which makes them genetically advantageous in cold climates.
Widow’s Peak Hairline
A widow’s peak is a v-shaped point in the middle of a hairline, and a genetically dominant trait. There are no definitive studies on the commonness of this trait worldwide, and previous estimates vary wildly from as little as 3% of the population to as much as 81% exhibiting the trait.
Maybe geneticists disagreeing about everything is a dominant trait.
A bent pinky is a genetically dominant trait. Most of us have pinkies that curl imperceptibly towards the ring finger. For most people, it’s not serious, or even that noticeable, but for about one percent of the global population, it can be a genuine issue.