One in 500 children is born with a sixth finger. This condition is referred to as “polydactyly” or the development of an extra finger.
“Poly” for many and “dactylos” for fingers.
To many, this condition is considered just but a rare trait. In research done currently, it has been found out that a totally developed sixth finger can be of advantage.
This condition may occur due to different environmental factors which include; nutrients intake level or exposure to harmful chemicals before one gets pregnant.
When one has two thumbs, this condition is called “radial polydactyly“; radius being the bone that is in support of the thumb. When it is two little fingers, it is “ulnar polydactyly“, ulna being the bone supporting the little finger. When the sixth is between either of the other 3 fingers, this is referred to as “central polydactyly“.
This condition can also occur through genetics. A set of genes by name “hox genes” are liable for development of different body structures in the body. They may cause genetic polydactyly where one has six fingers.
The sixth finger is found to be made up of just tissues. This finger is most cases lacks bones or tendons which make it a bit weak compared to the other fingers. This finger functions only when it has fully developed and has bones or tendons.
It has not yet been proven whether the sixth finger is helpful and relevant in any way. However, this finger is seen to enhance motor abilities. In cases where the finger is fully developed, it may provide extra skills.
Surprisingly Polydactyly is not only limited to humans. A primate by name “Aye-Aye lemurs” is found to have an extra thumb. This thumb has bones and cartilage. This primate uses this extra thumb when looking for food. Nevertheless, their extra thumb, is found to move in three different directions.