Why do we have five fingers (Science Behind Fact)

Our fingers are one of the most important parts of our body.

We use them all the time, for almost every work, motor action and so on.

Most of the time, we do not even focus on how we use them or put a second thought to how they are.

But, why do we have five fingers, and how did we get them? 

Science and Evolutions

To trace back what happens, our arms and toes begin as tiny buds that sprouted from our sides when we are just four-week-old embryos.

Around the six weeks mark, these limb buds had grown longer and five rods of cartilage had appeared in their flattened tips.

As we hit the seven weeks, the cells between the rods have died away. What we are left with is sculpting five small fingers or toes from once-solid masses of flesh.
 
A team of scientists has recently discovered that this process is orchestrated by three molecules.

These molecules mark out their zones in the embryonic hand where the fingers are supposed to grow. They also mark out the spaces where they are destined to die.

This trinity is what gives way to the creation of music, writing and art and so much more.

Without it, our fingers would not exist. 
 
This three-molecule model was first thought of by the famous English mathematician, Alan Turing.

Back in 1952, Turing proposed a simple mathematical model in which two molecules could create patterns by spreading through tissues and interacting with each other.

This was a breakthrough as it helped us understand how different processes might happen.

For example, the first molecule might activate the second, while the second block the first. 
 
Modern scientists knew these molecules and knew that they would need to show up in the form of some sort of striped pattern.

In the case of humans, they’d either be active in the bits that become the fingers or the areas in between

. It is activated in a striped pattern from a very early stage of development.

This also seems to control the activity of other genes and if you get rid of it, its underlings lose their neat periodic patterns.
 
Just for an overview, the three molecules are called- Wnt, Bmp, and Sox9.

Researchers have found something very significant by comparing cells where Sox9 is active or inactive. They found two other groups of genes— Bmp and Wnt— also formed striped patterns.

Other different kinds of patterns have also been assessed among these molecules.

Bmp rises and falls in step with Sox9 and both are active in the digits.

Want is out of phase; it’s active in the gaps. The three molecules also affect each other: Bmp activates Sox9 while Wnt blocks it, and Sox9 blocks both of its partners.

All these molecules work together. These molecules seem to be working in a trinity rather than a pair.
 
Other things were also discovered during the research, such as the impact of other molecules that impact the trinity.

One such molecule might be the FGF, a protein that’s more concentrated at the fingertips than at the base of the hand.

It effectively increases the wavelength of the fingers as you move to the tip of the hand. This might explain why our fingers are slightly splayed, rather than strictly parallel.
 
Yet nobody has been able to find an answer to the question of why we possess exactly 5 fingers.

Science is still trying to find traces and origins to answer this question, in the hope one day we can pinpoint the actual cause.