#EvolutionOfHands #HumanAnatomy #NumberOfFingers
Have you ever stopped to wonder why humans have five fingers on each hand, instead of 3, 7, or 9? 🧐 Why did evolution decide that five was the magic number for our hands? Let’s delve into this fascinating question and explore the reasons behind our unique anatomy.
## Evolutionary Advantage 🌱
### The Power of 5️⃣
The number 5️⃣ of fingers on each hand is not a random choice by evolution. In fact, having five fingers offers a perfect balance between dexterity and complexity. This number allows us to perform intricate tasks with ease, such as writing, typing, or playing musical instruments. Imagine trying to play the piano with only 3 fingers on each hand or juggling with 9 fingers – it would be quite a challenge!
### Efficiency in Design 🎨
Having five fingers per hand is also a result of evolutionary efficiency. Developing and maintaining additional fingers would require more energy and resources from the body. Evolution tends to favor simplicity and functionality, and five fingers strike the perfect balance between versatility and conservation.
## Practicality vs. Innovation 🤔
### The Case for 7️⃣ or 9️⃣
While having 5 fingers is undoubtedly advantageous, one may wonder if having 7 or 9 fingers could offer even more benefits. In theory, having more fingers could increase our hand’s capabilities and versatility. However, in practice, having too many fingers could lead to clumsiness and reduced functionality. It’s all about finding the perfect balance between innovation and practicality.
### Two Thumbs Up! 👍
As for having two thumbs and a single central finger, it may seem like an interesting concept on paper. However, having multiple thumbs could disrupt the delicate balance and coordination of our hands. Thumbs play a crucial role in gripping and manipulating objects, and having two of them could complicate rather than enhance our abilities.
In conclusion, the number of fingers we have on each hand is not a random quirk of evolution but a carefully crafted design that balances dexterity, efficiency, and practicality. Next time you look at your hand, remember that those five fingers are the result of millions of years of evolution, fine-tuned to perfection. 🌟
So, why five fingers? Because it’s the Goldilocks number that’s just right for all our hand-related needs! 🖐 #FiveFingersFTW
I think all tetrapods have the basis for 5 fingers from tiktaalik, and we just kinda kept our number of digits while other species lowered or effectively lowered their number of digits down (like ungulates, dogs, etc). I think it’s probably more-so that it’s a lot harder to add digits than it is to reduce/maintain them, so a fair bit of chance. I supposed if the OG tetrapod had 8 fingers maybe it would still reduce down to 5 if that’s ‘optimal’ but I have my doubts
Some studies have found polydactyly (6 fingers/ extra finger) is a dominant trait which is kind of interesting as to why 5 fingers have become so common. 5 fingers was obviously dominant in the evolutionary aspect
In 2010 a complete specimen of a 380 million year old fossil of a lobe-finned fish, Elpistostege was discovered. Lobe-finned fish are considered to be ancestral to amphibians and all amniota.
Elpistostege had five bones at the ends of its loby fins. This appears to be the oldest evidence for the five digits (or vestigial remnants of digits) shared by all amniota.
https://www.scientificamerican.com/article/how-a-380-million-year-old-fish-gave-us-fingers/#:~:text=The%20presence%20of%20small%20rows,than%20380%20million%20years%20ago.
evolution isn’t a master designer or anything like that. it’s just survival. as far as the individuals with whatever trait it is can survive long enough to pass it on, the trait will be there.
I’m guessing whatever animal had the five digits on a hand, survived the most and produced the most offspring so that trait was dominant
Neil Shubin’s book “Your Inner Fish” discusses the history of 5 fingers in some detail. The anatomic structure of limbs (fins) apparently developed in fish even before land animals existed, and followed a pattern of 1 bone, 2 bones, many bones, terminating in 5 bones from proximal to distal. So humans have 1 bone in the upper arm (humerus), 2 bones in the forearm (radius and ulna), the wrist with many bones, and then 5 digits. This pattern was largely maintained over hundreds of millions of years of evolution.
So 5 rays in a fishy fin existed long before anything that could be called a “hand”.
We’ll never know for certain.
But the thing to understand about evolution is that evolution does not favour optimal design. It favours optimal breeding. Whatever helps you survive long enough to pass on your genetic material.
Let’s say you had for example, a completely useless finger on the back of your head. It does absolutely nothing. Will evolution get rid of it? No, unless people born without that finger breed more successfully than you.
The basic 5 digit design must have been extremely successful at one time, as almost everything that has a spine has 5 digits, or the remnants of 5 digits.
You could say it’s a mix of evolutionary competition and randomness of life. I believe the running theory for why five is that the fish that came out of the sea already had bony fins with five bones, which eventually evolved into fingers.
If all that tracks then we have 5 fingers because it was an optimal number to give their fins enough area and power for the way they moved. Also, it kinda makes sense that it was the ones who had strong front fins that crawled onto land, yeah?
It’s been a while, so i may be misremembering something or there’s been a new theory since
I think this is just a matter of evolution. Our distant ancestors probably did have more fingers or appendages, but over time the ones that were not needed for survival evolved away by probably fusing to other fingers or simply not growing.
My guess is that we retained the five most useful ones that help us with grip, stability, and movement for our physical stature across the terrain that we encounter. If you notice, we have heels on our hands and feet that dig into the platform we put them on, which makes it less likely for finger like appendages around it to not get damaged during movement (so evolutionarily it won’t make sense for fingers to grow there), but we have just enough count of fingers to keep us mobile yet stable. With this claim, you could argue we could be better off with a front heel and a rear heal for movement or rather just a single heel without any fingers, but then we would not be able to grab our food when feeding unless we went the route of Elephants.
Speaking of, Elephants are a good example of why having fingers in general are a benefit. They have heels on the rear side of their feet, but they also have five counts of fingers spread across the front half of their feet that flex when they move around, giving them support from all possible directions of movement. Any more fingers than five, and they get diminishing returns; six or more won’t do them any good if they have a heel to support their massive weights, so they have five fingers that allows them to flex so they can move across different terrains.
Also, we could have evolved the way of sloths or birds which have fewer fingers, but those animals are compensated by either sharp talons or lengthy claws for feeding purposes that are largely enabled because of their methods of mobility – – flight and climbing trees. In contrast to birds, our distant ancestors did not evolve to fly but they did evolve somewhat similar to sloths and hence we have have similar lengths of fingers and not stumps like Elephants. Slots have fewer fingers because they hang from trees and grip things by folding their palms inwards, whereas our ancestors evolved to traverse a-top of trees as well as on land, grab things with however many fingers they had at the time, and eventually kept the ones that were useful. Also, our feet can be thought of as having two heels, but we still have the same amount of fingers that allow us to grip on terrains that allow us to move forward, and hence away from potential predators.
All of this to day that we could have evolved in any possible way as required for our survival, which requires being able to get away from our predators movement and stability) and being able to feed ourselves (grip-ability), but our evolution took this path that it deemed the most efficient.
Evolution can only act on what came before it.
Humans are evolved from amphibians, which, in the distant past, had up to 8 digits per limb. Different species will have had different numbers.
For some reason, at some point in our evolutionary history between these amphibians and us, a species with 5 digits per limb became very successful, and is the common ancestor to the terrestrial tetrapods (4 legged animals).
It might be that there was something better about 5 digits (a good compromise between utility and cost, maybe?) or it could be a complete coincidence. The species could have been successful for some other reason, and just happened to have 5 digits.
Since our ancestors had 5 digits, and because since then we never had an additional mutation to give us 4 or 6 fingers that became dominant, we still 5 digits.
This is one of those things where we likely will never know a great answer. It evolved that way. Evolution is a messy process and does not optimize for anything in particular except ability to pass on genetics to the next generation. At some point, the five digit limb became a dominant one and there isn’t really much selective pressure one way or the other.
We can make some educated guesses, though. Fewer fingers gives you less dexterity and tool control. More fingers would require more total muscle mass to maintain the same grip strength, and a more complex system that would be bulkier and have higher energy requirements. 5 worked out to be a good balance between different factors, and the rest is up to the non deterministic nature of evolution.