As you can see, Chimerism can lead to this striking image of a man with two very different colour eyes. It occurs when people carry a second set of DNA in them, which materializes in strange, but usually safe, ways like this.
An average human can see only a million colours, but if you are special or I should say, tetra chromatic, you may witness more than a hundred colours! Some of us possess a fourth cone cell to identify colours.
The condition is called Distichiasis and is not harmful in anyway. It only means that you have a second row of eyelashes. If maintained properly, it can really bring out your eyes. Elizabeth Taylor certainly rocked those.
A gene called Proprotein convertase subtilisin/kexin type 9 (PCSK9) exists in all of us, but a small subset of the population has less than the rest of us, which puts them at lower risk for cardiovascular diseases.
It’s not dangerous but it’s kind of cool! It's proof that once all living things had gills. Only 5% of the people in the world have this. Again, there's no use and neither is it dangerous.
It is also called palmaris longus. Basically it was a muscle that helped our ancestors climb trees. Though we don't use it anymore, some people do have it. It can be used if someone needs a tendon graft, but functionally it is utterly useless. To check if you have it, put your arm on a flat surface then touch your thumb with your pinky finger, it will pop out of your wrist.
DEC2 is a gene basically allows a person to have a less sleep cycle compared to others, giving them the extra time to achieve greater things!