It's time to bust the lid off some common misconceptions about recessive genes. First of all, when you hear the term "recessive genes," you probably think of physical characteristics in humans that are less common. But that's the wrong way to look at things. It's true that many recessive traits tend to be less common, but the fact is that many "normal" human features you see every day are actually recessive! And we've got a list of recessive human genes to prove it.
It works like this: A recessive trait is one that usually only manifests itself when there is no dominant gene present. For example, if your mom has red hair and your dad has black hair, chances are you're going to have black hair because the gene for that color is dominant. As it turns out, many traits we now take for granted are so common that the dominant gene is either not around as much or gone altogether. A few of the most common recessive genes in humans are ones you would think are dominant.
But let's see if we can surprise you a little. Think you can guess the most common recessive human genes? Take a look at our recessive human traits list, and see if we can shock you within the first five.
Well, are you surprised yet? You heard that right, having five fingers is actually a recessive human trait compared to six fingers! So how did it happen that everyone except a very small percentage of the population has five-fingered hands?
Well, we're not really sure, but at some point long ago, having five fingers per hand became more prominent.
The trait may be recessive, but because there are so few dominant six-finger genes floating around, we're all still slapping high fives.
We definitely see more free-fingered folks around than we do people with webbed or fused fingers, partially because there are so few genes of this type floating around in the population.
You probably had some kid in class with you back in elementary school who boasted about being double-jointed. Whether they were telling the truth or not, they were actually bragging about a dominant trait. Having joints like most of the population is actually genetically recessive compared to having joint hypermobility, also called being double-jointed.
This is less likely to affect Europeans, but worldwide about 25% of people are double-jointed, meaning that a whopping three-quarters of us are expressing a recessive trait!
You don't see a lot of people walking around with Bride-of-Frankenstein hair. So you might be surprised to know that having streakless hair, as the majority of people do, is a recessive trait.
You might be surprised to find that dwarfism is a mostly dominant trait. But that doesn't mean that those with dwarfism invariably have parents with dwarfism.
According to the Tech Museum of Information: "Around 7 out of 8 cases of dwarfism result from DNA changes in the FGFR3 gene that appear out of nowhere. Literally. These changes (or mutations) happen in the sperm or the egg or very early on in development."
Still, roughly 85% of the population shows the recessive trait and is allergic to poison ivy, and 50 million Americans per year have the rashes to prove it.
