It's time to bust the lid off of 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 important and "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 genome is one that only manifests itself when there is no dominant gene present. For example, if your mom had red hair and your dad had black hair, then you're going to have black hair because that color hair is the dominant one. However, if both your parents have red hair, you're going to have red hair! 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 even 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 genes list, and see if we're able to shock you within the first five traits.
Having Five Fingers
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 a five-fingered hand? Well, historically it hasn't been exactly attractive to have an extra digit, so most people walking around today are carrying two recessive alleles to pass on to their offspring. The gene may be recessive, but because there are so few dominant six-finger genes floating around, we're all still slapping high fives.
Because the gene for this disorder is actually autosomal dominant, if you get a gene for this it will express itself. However, we definitely see more free-fingered folks around than people with webbed or fused fingers, partially because there are so few genes of this type floating around in the population. Only 3-10 in every 10,000 births shows evidence of webbed or fused fingers.
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. You see, having normal joints like most of the population is actually genetically recessive compared to hypermobile joints, also falsely 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 gene!
Hair Without White Streaks
You don't see a lot of people walking around with bride-of-Frankenstein hair. Based on this, you might be surprised to know that having streakless hair, like the majority of us, is a recessive trait. We're not sure exactly how often the expression of the dominant trait occurs in humans, but we do know that the number of people with white streaks due to genetics are less than 200,000 people in the US alone.